Photorefractive Keratectomy

Anatomy and Physiology

Laser refractive surgeries act upon the surface of the cornea—the transparent, dome-shaped, outermost layer that covers the front of the eye. The first step of PRK requires the complete removal of the superficial corneal epithelium down to Bowman's layer. The excimer laser then ablates the stroma, thereby remodeling the corneal surface. Further details about the excimer laser are provided below. Following the procedure, re-epithelialization occurs through the migration of fibroblasts and the synthesis of collagen.[2] PRK is a laser-based refractive surgery that corrects common visual disorders, such as myopia, hyperopia, and astigmatism, by reshaping the cornea's anterior surface. An in-depth understanding of the corneal anatomy and physiology is crucial for understanding the principles, outcomes, and limitations of PRK.[13]

Structure of the Cornea

The cornea is the transparent, avascular anterior part of the eye, accounting for approximately two-thirds of the eye's total refractive power [approximately 43 diopters (D)]. Structurally, it is about 500 to 600 µm thick at the center and is slightly thicker at the periphery. The cornea is composed of 5 primary layers (from anterior to posterior).

• Epithelium: The outermost layer (approximately 50 µm thick) is composed of stratified squamous non-keratinized epithelial cells. This layer acts as a barrier against microbial invasion and minor trauma and plays a key role in corneal hydration and drug absorption. In PRK, this layer is completely removed before laser ablation.

• Bowman's layer: A thin, acellular, collagen-rich layer beneath the epithelium. This layer does not regenerate if damaged and plays a limited role in the refraction process. The integrity of this layer may influence healing responses post-PRK.

• Stroma: Constituting nearly 90% of corneal thickness, the stroma is composed mainly of regularly arranged collagen fibrils (types I and V) and keratocytes. This layer contributes significantly to the cornea's biomechanical strength and transparency. PRK involves precise photoablation of the anterior stroma to reshape the corneal curvature.

• Descemet's membrane: A thin, elastic basement membrane supporting the endothelium. Descemet's membrane serves as a protective barrier. This membrane regenerates if partially damaged but is not typically involved in PRK.

• Endothelium: A monolayer of hexagonal cells on the posterior corneal surface responsible for maintaining corneal deturgescence through active ion pumping. Endothelial cells do not regenerate. Although PRK does not directly affect this layer, long-term ectasia or inflammation can compromise its function.[14]

Tear Film and Epithelium

The precorneal tear film is a trilaminar structure composed of lipid (outermost), aqueous, and mucin layers. This film is critical for maintaining optical clarity and corneal nutrition. Post-PRK epithelial disruption can destabilize the tear film, leading to transient or prolonged dry eye symptoms. The restoration of epithelial integrity is a key component of postoperative recovery.[15]

Corneal Nerve Supply

The long ciliary nerves from the ophthalmic branch of the trigeminal nerve densely innervate the cornea. These sensory fibers enter the cornea radially through the stroma and form dense sub-basal and epithelial nerve plexuses. During PRK, nerve endings are disrupted due to the removal of epithelium and stromal ablation, leading to decreased corneal sensitivity and an altered blink reflex. Nerve regeneration begins within weeks but may take months to normalize, which can impact healing, tear production, and postoperative discomfort.[16]

Corneal Biomechanics and Healing

Biomechanically, the anterior one-third of the corneal stroma provides the most tensile strength. PRK removes part of the anterior stroma, which can lead to minor reductions in structural integrity compared to deeper lamellar procedures, such as LASIK. However, the absence of a flap in PRK preserves overall biomechanical stability better over the long term.[17]

Healing after PRK involves 3 overlapping phases:

• Epithelial healing (first 3-5 days): Basal epithelial cells proliferate and migrate to cover the ablated area. Complete epithelialization is typically achieved within 3 to 7 days. Mitomycin C may be used intraoperatively to reduce the risk of haze during this phase.

• Stromal remodeling (weeks to months): Keratocytes undergo apoptosis near the ablation zone, followed by repopulation and matrix remodeling. Myofibroblast transformation during healing can lead to subepithelial haze, especially with higher corrections.

• Neurotrophic recovery (months): Corneal nerves regenerate gradually over several months. During this time, patients may experience decreased corneal sensitivity, dry eye, and photophobia.[2]

Anterior Segment Considerations

In addition to corneal tissue, adjacent anatomical structures influence PRK outcomes:

• Limbus: The limbal stem cells support epithelial regeneration. Careful epithelial debridement should spare limbal cells to prevent healing defects.
• Anterior chamber: Although unaffected directly, inflammation after PRK may cause cells and flare-ups in the anterior chamber.
• Iris and pupil dynamics: The pupil diameter influences the ablation zone. An overly small optical zone relative to mesopic pupil size may cause glare or halos postoperatively.[18]

Refractive Index and Optical Zone

The refractive index of the cornea (approximately 1.376) contributes to its high refractive power. PRK modifies the anterior corneal curvature to correct refractive errors. Myopic corrections flatten the central cornea, whereas hyperopic treatments steepen it peripherally. The optical and transition zones must be tailored to individual pupil size to optimize postoperative visual quality.[19]

Role of the Cornea in Vision

The cornea is not only the primary refractive surface but also crucial for image quality. Any surface irregularity, scarring, or biomechanical instability introduced during or after PRK can lead to higher-order aberrations, reduced contrast sensitivity, or visual distortions.[17]

Immunologic Privilege and Inflammatory Response

The cornea possesses immune privilege due to avascularity and expression of immunosuppressive molecules. Nonetheless, surgical trauma during PRK induces inflammatory mediators, such as interleukin-1, tumor necrosis factor-alpha, and matrix metalloproteinases. These mediators modulate keratocyte activity, healing, and haze formation. Topical corticosteroids and anti-scarring agents, such as mitomycin-C, modulate this immune response to prevent haze and optimize visual outcomes. Understanding the anatomical and physiological nuances of the cornea is fundamental to performing PRK safely and effectively. PRK exploits the anterior cornea's accessibility, regenerative epithelial potential, and avascularity to achieve long-term refractive correction. However, the procedure also relies on the precision of ablation patterns, wound healing, and nerve regeneration. A thorough understanding of these anatomical structures and physiological mechanisms enables the interprofessional team—comprising surgeons, optometrists, technicians, and nurses—to anticipate complications, set realistic patient expectations, and promote optimal healing.[20]

Indications

PRK is an option in patients with myopia up to −12 D, astigmatism up to 6 D, and hyperopia up to 5 D.[21] Results are better and more predictable in low ranges; high refractive error correlates with a higher likelihood of regression and corneal haze.[2]

PRK offers several advantages over other surgical options for the correction of visual refractive errors:

• Some patients may be reluctant to undergo procedures that require flap formation due to fear of related complications such as incomplete flap, free flap, buttonhole, flap dislocation, epithelial ingrowth, folds, and wrinkles.
• PRK may also be preferable in patients, professional athletes, or other individuals with a higher risk of flap dislocation.[2]
• Some ophthalmologists who rarely perform refractive surgery may elect to perform PRK over LASIK, which is generally considered a more complex procedure.
• PRK may be an option for select patients in whom LASIK is contraindicated, such as those with thin corneas, epithelial basement membrane dystrophy (due to the risk of epithelial ingrowth), a history of recurrent erosions, anteriorly placed scleral buckles, or very flat or very steep corneas.
• PRK may be performed as an enhancement procedure to correct residual refractive errors following corneal transplantation, penetrating keratoplasty, LASIK, cataract surgery, or other surgeries of the eye. Studies on the use of PRK as an enhancement procedure have demonstrated excellent safety and efficacy.[22][23]

PRK is a surface ablation refractive surgery that reshapes the anterior corneal surface to correct refractive errors. This procedure remains an essential alternative to LASIK in specific patient populations due to its unique safety profile and long-term efficacy. Although both PRK and LASIK utilize excimer laser ablation to modify the corneal curvature, PRK does not involve flap creation, preserving more corneal biomechanics and offering advantages in select indications.[24]

Myopia (Nearsightedness)

PRK is most commonly indicated for the correction of low to moderate myopia, generally ranging from −1.00 D to approximately −6.00 D. However, some studies have demonstrated safe outcomes even in higher ranges when residual stromal thickness is adequate. By flattening the central cornea, PRK reduces its refractive power, allowing light to focus more accurately on the retina. Patients with thin corneas who are poor candidates for LASIK due to inadequate flap thickness can benefit from PRK.[25]

Hyperopia (Farsightedness)

Although less commonly performed than myopic corrections, PRK is also indicated for low-to-moderate hyperopia (up to +3.00 D). In these cases, the excimer laser steepens the central cornea to increase its refractive power. However, postoperative regression and increased risk of haze are more prevalent in hyperopic ablations, making careful patient selection and close follow-up essential.[26]

Astigmatism

PRK effectively corrects regular astigmatism up to ±4.00 D by selectively ablating the steepest meridian to regularize the corneal curvature. Patients with mixed astigmatism (both myopic and hyperopic components) can also be considered after proper corneal mapping and wavefront analysis.[27]

Thin Corneas or Low Residual Stromal Thickness

One of the most significant advantages of PRK over LASIK is the preservation of corneal structural integrity. As PRK does not involve the creation of a corneal flap, it conserves more stromal tissue, making it suitable for patients with thin corneas (typically <500 µm central thickness) or those in whom LASIK leaves an inadequate residual stromal bed. Maintaining sufficient stromal tissue is crucial in preventing postoperative ectasia, a progressive disorder characterized by corneal thinning.[12]

Occupational or Lifestyle Considerations

PRK is particularly suitable for individuals in occupations or environments where ocular trauma is a risk, such as:

• Military personnel
• Police officers
• Firefighters
• Athletes (eg, boxers, martial artists, and swimmers)

The absence of a corneal flap eliminates the risk of flap displacement, making PRK safer in these high-risk scenarios. In contrast, LASIK flaps can be dislocated or traumatized even years after surgery, especially under blunt force.[28]

Previous Corneal Surgery or Scarring

Patients with a history of prior corneal surgeries, such as radial keratotomy or LASIK enhancements, may be at risk for flap complications or unpredictable healing outcomes. PRK is often considered in such cases where flap creation is technically challenging or contraindicated. Similarly, in eyes with mild anterior stromal scars, PRK can serve both refractive and therapeutic purposes by ablating superficial opacities while also correcting refractive errors.[29]

Recurrent Corneal Erosion or Epithelial Basement Membrane Dystrophy

PRK is beneficial for patients with recurrent corneal erosion syndrome or epithelial basement membrane dystrophy, where the removal of the epithelium and laser treatment may help re-establish a stronger epithelial adhesion complex. In such cases, PRK may provide both therapeutic and refractive benefits, leading to long-term symptomatic relief and improved vision.[30]

Refractive Correction After Cataract or Intraocular Lens Surgery

PRK can be used to correct residual refractive error following cataract surgery or refractive lens exchange, particularly in pseudophakic patients with monofocal intraocular lenses who desire spectacle independence. This procedure is also helpful in fine-tuning outcomes after the implantation of multifocal or toric intraocular lenses. Careful biometry and topography are necessary in these patients to ensure predictable results.[31]

Anisometropia

PRK is effective in treating significant interocular refractive differences (anisometropia), particularly in individuals who are intolerant to contact lenses or spectacle correction. In such cases, PRK offers the opportunity to equalize refractive status and reduce image size disparity (aniseikonia), enhancing binocular vision and comfort.[32]

Contact Lens Intolerance

Patients with chronic discomfort, corneal neovascularization, or epithelial changes from contact lens wear may benefit from PRK. This population often seeks refractive surgery as a means of achieving spectacle independence without the risks associated with LASIK, particularly when long-term lens wear has induced corneal hypoxia.[33]

Suspected Corneal Surface Irregularities Not Amenable to LASIK

PRK is also indicated in patients with mild irregular corneal topography or forme fruste keratoconus, provided they undergo careful screening. When combined with corneal collagen cross-linking, PRK can provide visual rehabilitation in early keratoconus, offering some degree of refractive correction.[32]

Enhancement After Previous Refractive Surgery

PRK is often used as an enhancement procedure in cases of residual or regressed refractive error after prior LASIK or PRK. Because it avoids flap manipulation, PRK is particularly suitable for enhancement following flap-based procedures.[34]

Dry Eye Syndrome or Ocular Surface Disease

Although epithelial disruption in PRK can transiently worsen dry eye symptoms, many patients with preexisting dry eye may be better suited to PRK than LASIK, which severs more corneal nerves and may exacerbate dry eye over the long term. With careful management, including preoperative ocular surface optimization and postoperative lubrication, PRK remains a viable option in this group.[35]

Topography-Guided or Wavefront-Optimized Ablations

In eyes with visually significant higher-order aberrations or mild corneal irregularities, PRK can be combined with customized ablation profiles (topography-guided or wavefront-guided) to improve visual quality beyond simple sphere and cylinder correction. These advanced laser techniques are instrumental in treating night vision disturbances, glare, and halos.[8]

Pediatric or Amblyopic Indications (Off-Label Use)

While not a primary indication, PRK has been explored off-label in pediatric patients with anisometropic amblyopia refractory to conventional therapies. In carefully selected cases, PRK may provide an alternative to optical correction or serve as a tool in amblyopia management to enhance binocular vision.

In summary, PRK is a versatile and time-tested procedure that offers effective refractive correction in a wide range of clinical situations. The indications of PRK extend beyond simple myopia correction and encompass a broad array of anatomic, occupational, and therapeutic considerations. PRK remains the preferred option in patients with thin corneas, those with ocular surface disorders, and those at risk of trauma, due to the absence of a flap. With the evolution of laser technology and adjunctive therapies such as mitomycin-C and crosslinking, PRK continues to offer excellent safety and efficacy in both primary and enhancement settings. Understanding its broad indication spectrum allows clinicians to tailor refractive solutions to the individual's anatomical and functional needs while minimizing complications and optimizing outcomes.[36]

Contraindications

PRK has evolved into a safe and effective refractive surgical option for correcting myopia, hyperopia, and astigmatism. However, like any surgical procedure, PRK has specific contraindications that must be carefully considered to ensure patient safety and optimize outcomes. Contraindications can be classified into absolute and relative categories. While absolute contraindications disqualify a patient from undergoing PRK, relative ones require clinical judgment and thorough preoperative assessment before proceeding. Failure to recognize contraindications can lead to poor visual outcomes, corneal complications, or the progression of underlying conditions. There are many absolute and relative contraindications for laser refractive surgery, as proposed by the FDA and the American Academy of Ophthalmology (AAO). Patients should have a stable refraction within ±0.5 D for at least 1 year before PRK.[37]

Absolute Contraindications

PRK is not a desirable therapy in patients with significant cataract, unstable glaucoma, or uncontrolled external diseases, such as blepharitis, dry eye syndrome, and atopy or allergy. Keratoconus and other abnormalities of the cornea, such as corneal ectasias, thinning, edema, interstitial or neurotrophic keratitis, and extensive vascularization, are considered absolute contraindications. However, a study found that PRK in patients with keratoconus with a predicted central corneal thickness of over 450 µm resulted in improved visual outcomes and did not lead to keratoconus progression.[38] Patients with active systemic connective tissue diseases such as systemic lupus erythematosus and rheumatoid arthritis are considered poor candidates due to the increased risk of corneal haze and corneal melt.[39]

Relative Contraindications

PRK is relatively contraindicated in pregnant women or nursing mothers, as hormonal influences may result in changes in refractive error. Furthermore, medications received postoperatively may be transmitted indirectly to the fetus or nursing infant. Caution is also necessary for patients with functional monocularity, ocular conditions that limit visual function, excessively steep or flat corneas, abnormal corneal topography, significant irregular astigmatism, inadequately controlled dry eye, uveitis, and glaucoma. A history of herpes simplex keratitis may be considered a relative contraindication; however, preoperative treatment with systemic antivirals for several months postoperatively can minimize the risk of herpes simplex keratitis reactivation. Patients with uncontrolled diabetes mellitus are at higher risk of refractive instability or poor wound healing. Patients on medications with a high risk of ocular adverse effects, such as amiodarone, isotretinoin, and sumatriptan, are generally recommended to avoid refractive surgeries.[39]

Corneal Ectatic Disorders (Absolute)

The presence of keratoconus, pellucid marginal degeneration, or other corneal ectasias is an absolute contraindication for PRK. Ablation in these eyes may lead to further biomechanical instability, exacerbating ectasia and leading to progressive corneal thinning, steepening, and visual distortion. Corneal topography and tomography (eg, Pentacam and Orbscan) should be used to detect early or subclinical signs (forme fruste keratoconus), such as inferior steepening, asymmetric bow-tie patterns, or reduced corneal thickness. In such cases, crosslinking may be considered, but PRK should be avoided.[40]

Thin Corneas with Inadequate Residual Stromal Bed (Absolute)

Although PRK conserves more stromal tissue than LASIK due to the absence of a flap, there is still a minimum residual stromal bed requirement. A cornea that is too thin to accommodate the planned ablation depth (while preserving at least 250 to 300 µm of residual stromal bed) is contraindicated. Central corneal thickness < 470 µm typically necessitates caution. Attempting PRK on such corneas increases the risk of postoperative haze, ectasia, and poor refractive predictability.[41]

Active Ocular Surface Disease (Absolute/Relative)

Conditions such as severe dry eye syndrome, ocular rosacea, blepharitis, meibomian gland dysfunction, and conjunctival disorders can impair epithelial healing and increase the risk of infection, corneal haze, and postoperative discomfort. Inflammation from these conditions compromises the quality of the tear film and epithelial integrity, leading to poor surgical outcomes. Although mild-to-moderate cases may be treated and optimized preoperatively, severe forms are a contraindication until ocular surface health is restored.[42]

Autoimmune and Connective Tissue Disorders (Absolute/Relative)

Systemic diseases, such as rheumatoid arthritis, lupus erythematosus, Sjögren syndrome, and scleroderma, are associated with impaired wound healing and an increased risk of corneal melting, delayed epithelial recovery, and infection. PRK should be avoided in patients with poorly controlled or active autoimmune disease. Well-controlled disease may be considered on a case-by-case basis, with close collaboration between the patient and their rheumatologist, and thorough preoperative counseling.[43]

Unstable or Progressive Refractive Error (Absolute)

PRK is contraindicated in patients with unstable refraction, typically defined as a change of more than 0.50 D in sphere or cylinder over the preceding 12 months. Progression may indicate early keratoconus or hormonal changes (eg, pregnancy, diabetes mellitus, and steroid use) and can lead to refractive regression postoperatively. Stable refraction should be documented with serial refractions and corneal imaging before surgery is planned.[44]

Significant Cataract or Presbyopia (Relative)

PRK is generally not recommended for older adults with early or moderate cataracts, as it does not address the underlying lens opacity. Performing refractive surgery in such eyes may result in suboptimal outcomes and patient dissatisfaction. Similarly, presbyopic patients expecting complete spectacle independence must be thoroughly counseled about the limitations of PRK in addressing near vision, particularly without monovision or multifocal options. Alternative approaches, such as refractive lens exchange, may be more appropriate.[45]

Uncontrolled Glaucoma (Absolute/Relative)

PRK is contraindicated in patients with uncontrolled or advanced glaucoma. Postoperative inflammation and steroid use can exacerbate intraocular pressure, leading to glaucomatous progression. Furthermore, the procedure alters corneal thickness, which may affect intraocular pressure measurements. In stable, well-controlled glaucoma, PRK may be considered after careful evaluation of visual fields, optic nerve status, and glaucoma medication burden.[46]

Pregnancy and Lactation (Absolute/Relative)

Hormonal fluctuations during pregnancy and lactation can cause transient changes in corneal curvature, thickness, and tear film stability, which can affect refractive measurements. Additionally, medications used perioperatively may pose risks to the fetus or neonate. Elective PRK should be deferred until several months postpartum and after cessation of breastfeeding, with confirmation of stable refraction.[47]

Herpetic Eye Disease (Relative)

Patients with a history of herpes simplex keratitis are at increased risk of viral reactivation following PRK due to the disruption of corneal nerves and the use of topical corticosteroids. PRK is not absolutely contraindicated in these patients, but requires prophylactic antiviral therapy and close postoperative monitoring. Patients with active herpetic disease should not undergo PRK.[48]

Unrealistic Expectations or Psychological Conditions (Absolute/Relative)

Patients with unrealistic expectations about surgical outcomes or those with psychological conditions such as body dysmorphic disorder or obsessive-compulsive traits may not be suitable candidates for PRK. Satisfaction with outcomes in these patients is often poor, regardless of visual results. Thorough counseling and psychological evaluation may be warranted before proceeding.[49]

Corneal Scarring or Opacities (Relative)

Corneal scars from trauma, infections, or previous surgery can interfere with the laser ablation profile and result in irregular astigmatism or suboptimal visual recovery. PRK may be performed in mild anterior stromal scars when combined with therapeutic ablation; however, significant scarring is generally considered a contraindication unless the goal is visual rehabilitation with informed consent.[50]

Chronic Use of Certain Medications (Relative)

Long-term use of systemic steroids, isotretinoin (Accutane), antipsychotics, or chemotherapy agents may impair corneal wound healing, affect tear production, and increase the risk of postoperative complications. A detailed medication history is essential, and PRK should be deferred or avoided in patients on these drugs unless cleared by their treating physician.[51]

Poor Healing Response or Keloid Tendency (Relative)

Patients with a history of hypertrophic scars or keloids may have an exaggerated healing response post-PRK, leading to haze formation and irregular healing. Although the cornea is immunologically privileged and does not scar the same way as skin, caution is advised in such patients, particularly in high refractive corrections where ablation depth is greater.[52]

Pediatric Age Group (Relative)

PRK is not routinely performed in children due to the difficulty in confirming refractive stability, increased healing response, and risk of regression. However, in cases of anisometropic amblyopia or refractive intolerance, PRK may be considered off-label after conventional therapy has failed, ideally in collaboration with a pediatric ophthalmologist.

PRK offers excellent refractive outcomes when performed in well-selected patients. However, careful screening for contraindications is essential to prevent complications such as ectasia, haze, infection, and patient dissatisfaction. Both ocular and systemic health must be thoroughly evaluated through clinical examination, topographic/tomographic analysis, and appropriate laboratory tests. Understanding and recognizing absolute and relative contraindications helps clinicians offer safer, more effective treatments tailored to individual needs. In cases where contraindications are identified, alternative options such as phakic intraocular lenses, refractive lens exchange, or non-surgical corrections should be considered.[53]

Equipment

PRK employs a 193-nm argon fluoride excimer laser to ablate the anterior corneal stroma. At 193 nm, a single photon can break the carbon-carbon and carbon-nitrogen bonds that form the peptide backbone of the corneal collagen molecules. With each pulse, the collagen polymer is broken into smaller fragments, and a discrete amount of corneal tissue is expelled from the surface.[54] The epithelial debridement may be performed through mechanical removal with a spatula, transepithelial removal with the femtosecond laser, application of a diluted alcohol solution, or use of a rotary brush.[55] Further details on the advantages and disadvantages associated with each technique are discussed below.

Equipment Used in Photorefractive Keratectomy

PRK is a sophisticated refractive surgical procedure that corrects myopia, hyperopia, and astigmatism by reshaping the corneal stroma using excimer laser ablation. The precision and safety of PRK largely depend on advanced instrumentation and meticulous procedural execution. The following section outlines and elaborates on the essential equipment used in PRK, including diagnostic devices, therapeutic lasers, intraoperative instruments, and postoperative adjuncts that collectively contribute to optimal outcomes.[56]

Excimer laser system: At the heart of PRK lies the excimer laser, which emits UV light at a wavelength of 193 nm. This high-energy beam breaks molecular bonds in the corneal tissue through a process called photoablation, removing tissue with micron-level precision and minimal thermal damage to surrounding structures.

Key components:

• Laser console: Contains the laser generator, beam delivery optics, and computerized control systems.
• Eye tracking system: Advanced multi-dimensional eye trackers (translational and rotational) compensate for involuntary eye movements, ensuring precise ablation.
• Beam profile: Can be broad beam, flying spot, or scanning slit, with flying spot systems offering the highest customization and least thermal damage.
• Software suite: Allows wavefront-guided, topography-guided, or standard ablation profiles to optimize outcomes based on individual ocular aberrations.[57]

Popular excimer laser platforms include the following:

• Alcon Wavelight EX500
• Schwind Amaris
• Zeiss MEL 90
• Nidek EC-5000
• Bausch + Lomb Technolas

These systems integrate patient interface modules, dynamic pupil tracking, and customized ablation algorithms for enhanced visual outcomes.[58]

Epithelial removal tools: PRK begins with the removal of the corneal epithelium to expose Bowman's layer for stromal ablation. Techniques and instruments for epithelial debridement include the following:

• Mechanical brushes and spatulas:
• Instruments, such as the Amoils brush or #15 blade, are commonly used to gently scrape away the epithelium.
• This method is effective, though it may cause uneven surfaces or trauma if not performed meticulously.

• Alcohol-assisted delamination:
• A 20% ethanol solution is applied for 20 to 40 seconds using a circular well (alcohol well) to loosen epithelial adhesion.
• The epithelium is then gently peeled off using a blunt spatula.
• Although efficient, this method may affect epithelial healing and induce inflammation.

• Transepithelial PRK:
• Modern excimer systems can now ablate both the epithelium and stroma in a single-step laser-based technique, improving comfort and reducing manual handling.

• Laser brush or epi-clear: Specialized devices designed to offer uniform, atraumatic epithelial removal, especially in eyes with thin or irregular corneas.[59]

Operating microscope and illumination system: A high-quality surgical microscope provides magnification and coaxial illumination, which are essential for visualization during PRK. Key features include the following:

• Adjustable magnification (typically ×6 to ×25)
• Anti-glare coating to reduce corneal reflection
• Coaxial LED or halogen illumination
• Compatibility with the laser interface

Microscopes from Carl Zeiss, Leica, and Haag-Streit are widely used in ophthalmic laser suites.[60]

Corneal pachymetry device: Central corneal thickness is a critical preoperative measurement for PRK candidacy and safety. Devices used include the following:

• Ultrasound pachymeter: Handheld, high-frequency probe for point-based thickness measurements.
• Optical pachymetry: Included in systems such as Pentacam or optical coherence tomography (OCT), offering pachymetric mapping across the cornea.

Ensuring adequate residual stromal thickness post-ablation (typically >250 µm) is essential to avoid ectasia.[61]

Topography and tomography systems: Corneal mapping is crucial for detecting early ectatic disorders and customizing ablation profiles.

• Placido disc-based topographers (eg, keratograph and topographic modeling system): Analyze anterior corneal curvature.
• Scheimpflug imaging systems (eg, Pentacam and Galilei): Provide full-thickness tomography, posterior corneal surface mapping, and elevation data.
• OCT-based devices: Offer high-resolution cross-sectional images of corneal layers.

These devices aid in planning customized procedures and excluding at-risk corneas.[62]

Wavefront aberrometry: Aberrometers quantify higher-order aberrations such as coma, trefoil, and spherical aberration, allowing wavefront-guided ablations that optimize night vision and contrast sensitivity. Key devices include the following:

• Hartmann-Shack Aberrometers
• iDesign Advanced WaveScan Studio
• Zywave Aberrometer (Bausch + Lomb)

Wavefront data are seamlessly integrated with the laser platform for personalized treatment profiles.[63]

Sterile surgical instruments and supplies:

• Eye speculum: Stainless steel or disposable to maintain eyelid separation.
• Sponges and cannulas: For balanced salt solution (BSS) irrigation and soaking mitomycin-C.
• Mitomycin-C (MMC) applicator: Used prophylactically (typically 0.02% for 12 to 30 seconds) in cases of high myopia to prevent subepithelial haze.[64]

Intraoperative medications:

• Topical anesthetics (eg, proparacaine): Ensure patient comfort.
• Antibiotics and anti-inflammatory drops: Reduce infection and inflammation postoperatively.
• Mydriatics and Miotics: Rarely needed in PRK unless combined with other procedures.[65]

Postoperative contact lenses: A bandage contact lens is applied at the end of PRK to protect the denuded corneal surface, reduce pain, and support re-epithelialization.

• Silicone hydrogel lenses with high oxygen permeability (eg, Acuvue Oasys and Air Optix Night & Day Aqua lenses) are preferred.
• Lenses are typically removed after 3 to 5 days when epithelial healing is complete.[66]

Postoperative diagnostic devices:

• Slit-lamp biomicroscope: Evaluates corneal healing, detects haze, epithelial defects, or infection.
• Anterior segment OCT: Monitors epithelial remodeling and haze depth.
• Refraction equipment: Assess visual outcomes and detect regression.[67]

Air filtration and surgical suite setup: PRK is performed in a clean, climate-controlled laser suite with the following:

• HEPA filtration units: Minimize the presence of airborne particles.
• Temperature and humidity regulation: Maintain excimer laser calibration.
• Surgeon console and video documentation systems: Facilitate procedure planning and audit.

The successful execution of PRK relies heavily on advanced, integrated equipment that ensures surgical precision, safety, and reproducibility. From diagnostic planning with corneal imaging systems to state-of-the-art excimer lasers and postoperative recovery tools, each element plays a vital role in the procedure's success. As technology continues to evolve, innovations in epithelial removal, wavefront customization, and intraoperative imaging are making PRK safer and more effective than ever. A thorough understanding of the equipment involved enables eye care professionals to optimize patient outcomes, reduce complications, and maintain the high standards expected in refractive surgery.[68]

Personnel

The successful execution of PRK relies not only on advanced technology but also on a well-coordinated interprofessional team. Each member plays a vital role in ensuring procedural efficiency, safety, and optimal patient outcomes. Collaboration, communication, and competence among personnel significantly contribute to patient-centered care in refractive surgery.

Ophthalmic Surgeon (Refractive Specialist)

The ophthalmic surgeon is the central figure in PRK. Board-certified and fellowship-trained in cornea or refractive surgery, the surgeon is responsible for preoperative evaluation, surgical planning, execution of laser ablation, and postoperative management. Expertise in interpreting diagnostic data, such as topography, wavefront analysis, and pachymetry, is crucial for selecting appropriate candidates and customizing treatments. The surgeon also manages intraoperative decision-making, epithelial removal techniques, and ensures aseptic surgical protocols. Postoperative follow-up care, including the recognition of complications such as haze or regression and the prescription of adjunctive therapies, also falls under their purview.[69]

Optometrist/Refractionist

Optometrists play a crucial role in preoperative workups, including accurate refraction, visual acuity assessment, and patient counseling. These healthcare professionals perform comprehensive ocular surface evaluations, contact lens discontinuation protocols, and assist in identifying contraindications such as keratoconus. Postoperatively, optometrists play a key role in assessing epithelial healing, managing mild inflammation, monitoring visual recovery, and reinforcing compliance with medication regimens.[70]

Ophthalmic Technician/Technologist

Technicians operate diagnostic imaging systems, such as corneal topography, pachymetry, wavefront aberrometry, and anterior segment OCT. These healthcare professionals ensure that all collected data are of high quality and reproducible, thereby aiding in surgical planning. During surgery, they assist in equipment setup, calibration of the excimer laser, and managing intraoperative tasks under the surgeon's guidance.[71]

Scrub Nurse/Operating Room Nurse

The scrub nurse ensures sterility and provides surgical instruments in a timely and efficient manner. Responsibilities include preparing the patient, draping, applying anesthetic drops, handling intraoperative supplies (eg, mitomycin-C and bandage contact lenses), and coordinating with the circulating nurse. The operating room nurse plays a critical role in workflow efficiency and preventing surgical delays.[72]

Circulating Nurse

The circulating nurse manages the surgical environment outside the sterile field, handles patient documentation, communicates with the control room or laboratory for any urgent requests, and provides any nonsterile items required by the surgeon or scrub nurse. This role also includes maintaining temperature and humidity parameters in the laser suite.[73]

Patient Counselor

Patient counselors provide preoperative education regarding PRK expectations, potential risks, and postoperative care. By facilitating informed consent and addressing patient anxiety or misconceptions, these healthcare professionals play a crucial role in enhancing patient satisfaction and adherence to post-surgical instructions.[74]

Biomedical Engineer/Laser Technician

Biomedical engineers or laser technicians maintain the laser platform, ensuring calibration, performing safety checks, and updating the software. These professionals troubleshoot intraoperative issues and ensure compliance with manufacturer and safety regulations.[75]

Administrative Staff

Scheduling, documentation, informed consent management, and insurance coordination are handled by administrative staff, enabling a smooth clinical workflow and efficient patient experience.[76]

Preparation

Careful patient selection and a thorough review of risks and benefits with patients are essential to maximizing good visual outcomes and patient satisfaction. Patients should receive information about the excimer laser and postoperative evaluation requirements through information sheets, patient counselors, and the ophthalmic surgeon. Patients should be informed about the sequence of events during surgery and what they may feel, see, smell, or hear, as this helps reduce their anxiety. The medical history and medication list of patients should be screened for any contraindications, as listed above. Most importantly, patients should only be selected if they have realistic expectations of visual outcomes. Patients should be made aware that the goal of refractive surgery is to allow for less reliance on glasses and contact lenses rather than to achieve the complete absence of refractive error.[77]

As part of the preoperative evaluation, the clinician must obtain the patient's refraction. Additionally, the patient's refractive stability, degree of refractive error, and astigmatism require documentation. Both manifest and cycloplegic refractions should take place—any disparity between these 2 values greater than 1 D of sphere warrants re-evaluation. Discrepancies may occur due to accommodative spasm, which is relatively common in middle-aged patients. Patients with a high degree of refractive error should know that outcomes are less predictable and that there remains an increased risk of scar formation and degradation of the optical performance.[78]

Several additional components of the preoperative evaluation are essential to ensure appropriate patient selection. The cornea should undergo evaluation for scars, vessels, or previous inflammation. Pupil size should be measured with the commercial pupillometer, as large pupils may contribute to glare and haloes postoperatively. Slit-lamp examination is necessary to rule out significant corneal abnormalities such as neovascularization, keratoconus, scarring, or the presence of a cataract. Corneal pachymetry allows for the determination of corneal thickness and detects keratoconus or other types of corneal ectasia. Eyelids and tear film require an examination for signs of blepharitis or dry eyes. Computed corneal topography allows for the detection of irregular astigmatism and keratoconus. Notably, soft contact lenses should not be worn for 3 days and hard contact lenses for 2 weeks before preoperative evaluation, as they can cause corneal warpage, which subsequently interferes with the accuracy of preoperative refractive measurements. Intraocular pressure should be measured to identify glaucoma. Fundoscopy is performed to rule out a retinal hole, degenerative retina, and other types of macular disease. Lastly, computed videokeratography may be conducted to rule out early keratoconus, corneal warpage, and asymmetrical or irregular astigmatism.[79]

Preoperative medications are generally given 20 minutes immediately before refractive surgery. To reduce postoperative pain, nonsteroidal anti-inflammatory drug (NSAID) drops such as ketorolac tromethamine 0.5% or diclofenac 0.1% should be administered, with a dosing regimen of  1 drop 3 times every 10 minutes. Topical anesthetic drops such as proparacaine hydrochloride 0.5% are also placed onto the eye immediately before surgery. Topical fluoroquinolones such as moxifloxacin 0.5% and gatifloxacin 0.3% are given to reduce the chance of infection. Sedation may be a consideration if the surgeon plans on holding the eye during ablation, but it is generally not recommended if the patient maintains self-fixation.[80]

The success of PRK is significantly influenced by meticulous preoperative preparation. A thorough and individualized approach ensures that only appropriate candidates are selected, optimizes surgical outcomes, minimizes complications, and enhances patient satisfaction. The preparatory phase involves a combination of clinical evaluations, diagnostic imaging, patient counseling, and coordinated team efforts to tailor care to each individual's ocular and systemic status.

Stepwise Patient Evaluation for PRK

Patient selection and medical history: Obtaining a detailed medical and ocular history is the initial step in PRK preparation. Patients should be evaluated for systemic diseases such as diabetes mellitus, autoimmune disorders, or collagen vascular diseases that can impair wound healing. A history of keloid formation, poor epithelial healing, or active dermatologic conditions around the eyes should also be obtained.

From an ocular standpoint, a history of herpes simplex virus keratitis; previous ocular surgeries, including refractive or cataract procedures; trauma; dry eye disease; or contact lens intolerance should be obtained. The duration and stability of refractive error should be verified, typically requiring a documented stable refraction for at least 12 months.[81]

Contact lens wear should be discontinued before examination—at least 2 weeks for soft lenses and 3 to 4 weeks for rigid gas permeable lenses—to prevent corneal warpage and ensure accurate corneal measurements.[82]

Refractive stability and visual acuity: Preoperative manifest and cycloplegic refraction should be stable and within the parameters amenable to PRK. The magnitude and type of refractive error, including sphere, cylinder, and axis, must be confirmed with repeated measurements. Patients with high degrees of myopia (>−8.00 D) or astigmatism (>4.00 D) may not be ideal candidates due to increased risk of haze and regression.

Best-corrected distance visual acuity (BCDVA) and uncorrected visual acuity should be recorded using Snellen or LogMAR charts. Discrepancies between manifest and cycloplegic refraction may indicate latent hyperopia or accommodative spasm, which warrants cautious evaluation.[81]

Ocular surface and tear film assessment: A healthy ocular surface is critical for both surgical accuracy and postoperative healing. Dry eye disease, blepharitis, and meibomian gland dysfunction should be identified and treated before surgery. Diagnostic tests include the following:

• Tear break-up time
• Schirmer's test
• Ocular surface staining (fluorescein or lissamine green)
• Meibography or lipid layer imaging (if available)

Artificial tears, punctal plugs, lid hygiene, and anti-inflammatory therapies may be used preoperatively to optimize tear film quality.[83]

Corneal topography and tomography: High-resolution corneal topography and tomography are indispensable for detecting irregular astigmatism, keratoconus, and other corneal ectasias. Devices such as Pentacam, Orbscan, and Galilei provide pachymetric maps, elevation data, and Belin/Ambrosio Enhanced Ectasia Display. Corneal thickness (central and thinnest point) is particularly crucial for PRK. Candidates should have a minimum residual stromal bed of approximately 250 µm after ablation and epithelium removal. Total corneal thickness should ideally be >480 to 500 µm, depending on the refractive correction required.[84]

Wavefront aberrometry and pupil size: Wavefront analysis can identify higher-order aberrations, which influence visual quality postoperatively, particularly in low-light conditions. Customized (wavefront-guided or wavefront-optimized) ablation profiles can be planned based on this analysis to improve visual outcomes.

Pupil size should be measured under both mesopic and scotopic conditions. Larger pupils may predispose to postoperative glare, halos, or night vision disturbances, especially when the optical zone of ablation is inadequate.[85]

Endothelial Cell Count and Anterior Segment Evaluation

In older patients or those with previous intraocular surgeries, specular microscopy may be performed to assess the corneal endothelium. Slit-lamp examination evaluates the cornea, conjunctiva, lens (to rule out early cataract), and anterior chamber. Gonioscopy is not routinely needed unless glaucoma or narrow angles are suspected.[86]

Retinal and Optic Nerve Examination

Dilated fundus examination: Dilated fundus examination is essential to exclude pre-existing retinal pathology, such as lattice degeneration or retinal holes, particularly in high myopes. In such cases, prophylactic laser photocoagulation may be advised before refractive surgery. The optic nerve should be assessed for signs of glaucoma or optic neuropathy. Intraocular pressure (IOP) should be recorded using Goldmann applanation tonometry, as post-PRK corneal thinning can affect future IOP measurements.[87]

Counseling and Informed Consent

Patient education and expectation management: Effective patient education and expectation management are cornerstones of successful refractive surgery. Patients should be informed that visual recovery after PRK is slower than LASIK, with discomfort and photophobia persisting for several days postoperatively. Patients should understand that optimal visual acuity may take several weeks to months to achieve.

Other counseling points include the following:

• Need for postoperative medications, such as antibiotics, steroids, or lubricants
• Possibility of corneal haze or regression
• Temporary use of a bandage contact lens
• Importance of UV protection post-surgery
• Risks of under- or overcorrection
• Enhancement procedures, if necessary

A thorough written informed consent outlining these details should be reviewed and signed by the patient.[88]

Preoperative Investigations and Systemic Considerations

Although not always mandatory, specific systemic investigations (eg, blood sugar, HIV/hepatitis B surface antigen/hepatitis C virus, and hemoglobin A_1c) may be requested to assess surgical fitness or risk of delayed healing. Patients on medications such as isotretinoin or amiodarone should avoid PRK due to epithelial toxicity and healing issues. Pregnancy and lactation are contraindications to elective refractive surgery due to hormonal effects on corneal curvature and refractive stability. Patients should be advised to delay surgery by at least 6 months postpartum.[89]

Scheduling and Pre-Surgical Instructions

Patients should be advised to stop wearing contact lenses as mentioned earlier and maintain good eyelid hygiene. Any ongoing ocular surface disease should be treated and stabilized for at least 1 to 2 weeks before surgery. Patients using topical antiglaucoma medications or steroids should be re-evaluated for compatibility and risk mitigation.

On the day of surgery, patients should adhere to the following guidelines:

• Avoid makeup, perfume, and lotions
• Arrange for transportation and an attendant
• Be advised to eat light meals
• Bring previous glasses or prescriptions
• Expect no driving for several days [90]

Interprofessional Coordination

An interprofessional team approach enhances patient safety and surgical outcomes. Ophthalmologists, optometrists, technicians, and nursing staff collaborate during preoperative assessments and imaging. Counselors and patient coordinators play a crucial role in addressing concerns, providing reminders for follow-up appointments, and ensuring compliance with preoperative instructions.

Conclusion

A well-structured preoperative preparation phase in PRK ensures the selection of appropriate candidates, improves visual outcomes, and minimizes postoperative complications. By integrating advanced diagnostic technology, patient-centered education, and interprofessional collaboration, clinicians can provide safe and effective care that meets the highest standards of refractive surgery.[91]

Technique or Treatment

Patient Positioning

Patient positioning should prioritize comfort. To allow for minimal head or body movements, legs should remain uncrossed, the neck not twisted, and patients should receive instruction to take shallow breaths. The head should be aligned such that when inserting the wire speculum, an equal amount of sclera is visible on the superior and inferior aspects of the globe. In unilateral surgeries, the nonoperative eye should be covered or taped closed, whereas the operative eye is clearly marked with an adhesive label or temporary mark on the forehead. Skin preparation is typically performed with alcohol wipes or povidone-iodine. A gauze pad may be placed between the operative eye and ear to absorb any fluid run-off.

Excimer Laser

On the day of surgery, the excimer laser should be calibrated and checked for an adequate, homogenous beam profile, alignment, and power output. Relevant data entry includes the patient's name, refraction, intended correction, epithelial removal technique, keratometry values, optical zone, and transition zone.

Pupil Fixation

Various techniques exist to ensure proper fixation of the pupil, which is essential to avoid complications such as decentration. Self-fixation, in which patients focus on a target light, is the most popular method, as it produces more accurate centration than globe immobilization by the ophthalmic surgeon.[21] Small microsaccades are not expected to adversely affect visual outcomes. Notably, this method is more difficult with higher corrections as the corneal surface may dry during the procedure. Many newer excimer lasers have built-in tracking systems that stop firing if there is significant eye deviation.[21] Regardless, the surgeon should continue to monitor the patient's globe and immediately stop treatment if fixation is lost. Other methods that are less commonly used to ensure pupil fixation include a fixation ring with or without suction and forceps.

Effective Communication with the patient is essential as they are expected to maintain fixation and remain motionless throughout the procedure. Surgeons should consistently reassure patients, encouraging relaxation and informing them in advance when vision is expected to blur. Other distractions should be minimal, as both the patient and surgeon may become distracted by any level of background conversation.

PRK Technique

Removal of superficial epithelial cells: The first step in PRK is the removal of the superficial epithelial cells, which can be performed through several techniques. Regardless of method, removal should be performed quickly to avoid desiccation and skillfully to avoid nicking Bowman's layer.

• Mechanical debridement: This technique involves using a blunt spatula to scrape off epithelium from the periphery toward the center. The next step is wiping a sponge hydrated with BSS or carboxymethylcellulose 0.5% across the cornea. Mechanical debridement does not rely on laser optics but may be time-consuming for inexperienced surgeons, increasing patient anxiety and reducing stromal hydration.[92]

• Laser-scrape technique: This method removes 38 to 45 μm of epithelial cells, and then residual debris is mechanically removed with a spatula.[92] The tear film requires irrigation with BSS before ablation to create a homogenous and smooth surface. One approach by which the surgeon may measure the depth to which epithelium may be removed is the use of blue fluorescence that appears as the epithelium is ablated. The disappearance of blue fluorescence indicates that the laser has reached the stroma and that the surgeon may begin to scrape away the debris. This technique tends to be easier for inexperienced ophthalmic surgeons; there is no reported difference in corneal wound healing response between the mechanical epithelial debridement and the laser-scrape technique.[93]

• Transepithelial technique: This technique also uses a blue fluorescent light to indicate completion of ablation and eliminates the need for manual spatula scraping to remove cellular debris.[93] The transepithelial technique is popular among patients but requires more time to master. Transepithelial debridement furthermore maintains a uniformly moist cornea and reduces the incidence of haze. Studies comparing mechanical and transepithelial debridement have demonstrated no significant differences in postoperative visual outcomes or incidence of higher-order aberrations.[94][95]

• Alcohol-assisted removal: Epithelial cells may alternatively be removed with a dilute solution of 20% alcohol. The alcohol solution is dropped onto a 6- or 7-mm optical marker placed on the cornea.[94] After 20 to 30 seconds, the optical marker is removed, and the ocular surface is irrigated with BSS to minimize toxicity to the limbal germinal epithelium. The epithelium is then easily removed and generally heals within two to three days. This technique appears to result in the best long-term visual outcomes and a faster mean epithelial healing time.[55][96] Notably, this technique may be associated with more postoperative dry eye symptoms.[97]

• Rotary brush-assisted removal: The surgeon may opt to use a rotary brush that contains fine hairs to remove the epithelium without injuring the underlying Bowman's layer. This technique allows for the epithelium to be easily removed and provides a smooth corneal surface. However, patients may lose fixation when the pupil becomes occluded with the brush, with an increased risk of the surgeon removing too much epithelium.[21][97]

Laser

After exposing the stroma, the laser is centered and focused according to the manufacturer's recommendations. Correction of myopia involves placing a large number of laser pulses centrally and fewer pulses in the periphery of the optical zone, thereby flattening the natural arc of the cornea. In contrast, the correction of hyperopia involves delivering the most significant number of laser pulses in the periphery to steepen the corneal arc.

Use of Collagen Crosslinking

There has been a trend to combine PRK with collagen crosslinking in patients with keratoconus and post-LASIK ectasia.[98][99] Collagen crosslinking is believed to have a therapeutic effect, which enhances corneal strength. A prospective study found that PRK crosslinking in patients with central corneal thickness between 450 and 474 μm or with borderline suspicious tomography—without meeting criteria for forme fruste keratoconus (early stage)—resulted in a comparable level of safety, efficacy, and stability outcomes compared to PRK in eyes with normal Central corneal thickness.[100] However, there is some concern that collagen crosslinking poses an increased risk of riboflavin or UV irradiation toxicity to the cornea.[101]

Application of Topical Mitomycin-C

Topical mitomycin-C is often applied as a soaked pledget on the ablated surface for 1 minute or less immediately after laser ablation to reduce the incidence of primary or recurrent haze.[102] Some clinicians may opt to apply mitomycin-C proportionally to the degree of preoperative refractive error. Mitomycin-C prevents cell proliferation by crosslinking DNA and inhibiting DNA synthesis. Notably, complications such as glaucoma and corneal perforation have been rarely correlated with mitomycin-C use, and refractive outcomes tend to be more variable when using mitomycin-C.[103] Most clinicians use 0.02% mitomycin-C; however, to avoid potential toxicity, some experts have proposed that high-dose mitomycin-C (0.02%) is only used for high myopia corrections, whereas low-dose mitomycin-C (0.002%) is the preferred choice for correcting low-to-moderate myopia.[104]

Post-Treatment Management

After laser ablation is complete, topical NSAID, antibiotic, and steroid drops are instilled. The ocular surface is irrigated with chilled BSS, which is believed to reduce postoperative haze formation.[23] The use of chilled BSS has been suggested to minimize inflammation and thereby reduce postoperative pain, although this has not been validated.[105] A soft bandage contact lens is placed on the corneal surface, and the wire speculum is removed.

Patients should be advised that their vision likely remains blurry while the corneal surface re-epithelializes. This vision change may hinder their ability to participate in work, hobbies, or travel. Patients should allow the healing process to complete before resuming activities that require critical vision. Ghosting, glare, and shadows in the vision are common, transient phenomena in the immediate postoperative period. These issues tend to worsen at night and are more prevalent in young patients with myopia and large pupillary diameters. Patients should also be instructed to maintain good ocular hygiene due to the increased risk of infection while the epithelium is regenerating.[21]

Post-Treatment Discomfort

Approximately 90% of patients experience no postoperative pain, whereas the remaining 10% typically experience mild-to-moderate pain or discomfort in the 24 to 36 hours following the procedure.[21] Postoperative pain is not correlated with gender, preoperative anxiety, or knowledge of the procedure.[106] Pain is most often managed with NSAID drops, such as ketorolac tromethamine 0.5% or diclofenac 0.1%, administered several times a day for 24 to 48 hours. NSAID drops inhibit prostaglandin synthesis to promote an analgesic effect; however, NSAID drops may slow the rate of epithelial regeneration and promote the formation of sterile infiltrates.[21] For this reason, NSAID drops should be used sparingly beyond 72 hours postoperatively. Breakthrough pain may be managed with oxycodone/acetaminophen 5/325 mg taken every 4 to 6 hours. Gabapentin and cold compresses have also shown clinical utility.[107]

Post-Treatment Medications

Other medications used in the postoperative management include topical fluoroquinolones, typically used 4 to 5 times daily for 5 to 7 days or until re-epithelialization is complete.[21] Topical anesthetics such as tetracaine 0.5% to 1% have been demonstrated to reduce pain scores without adverse effects of re-epithelialization or visual outcomes when administered every 30 minutes for the first 24 hours.[108] However, these topical anesthetic agents should be used sparingly and judiciously due to their risk of abuse and subsequent corneal perforation/melt.[109] Frequent use of non-preserved, chilled, artificial tears is also recommended to prevent irritation or discomfort associated with the use of a bandage soft contact lens.[110]

Topical corticosteroids are often used to prevent significant regression and postoperative haze. However, no consensus has been reached on the most appropriate duration of treatment. Among all topical steroids, prednisolone acetate, loteprednol, and fluorometholone are the most commonly used following PRK. Steroids may be administered 4 times daily for 1 week and tapered off over the following 3 weeks, or 5 times daily for 1 month and tapered off over 4 months. The latter regimen is typically reserved for patients with high levels of myopia.[21] When combined with NSAID drops, the incidence of sterile infiltrates in the postoperative period dramatically decreases. However, steroids carry an increased risk of ocular hypertension, ptosis, posterior subcapsular cataracts, and reactivation of herpes simplex keratitis. Risk factors for steroid-induced ocular hypertension include male sex, high central corneal thickness, lower mean keratometry power, high myopia, and corneal haze.[111] The risk of ocular hypertension is reduced using lower penetrating steroids such as fluorometholone or rimexolone rather than prednisolone acetate or dexamethasone.[21] Ocular hypertension should be treated by reducing or discontinuing the dose of topical steroids and administering a topical beta-blocker.

Post-Treatment Course

Re-epithelialization is complete in most patients by postoperative day 3; bandage soft contact lens, antibiotic drops, and NSAID drops may be discontinued at this time. Corneal videokeratoscopy should be performed at 1 month following refractive surgery to determine whether the ablation was centered correctly.

Table 1. Stepwise Procedure for Photorefractive Keratectomy

Complications

Pain

Mild pain or discomfort and keratoconjunctivitis sicca (dry eye) are the most common complications following refractive surgery. Discomfort and pain may be described as a sensation of having sand in my eye and should be managed with medications as listed above. Dry eye is one of the most common complications in patients receiving refractive surgery and a major cause of patient dissatisfaction. Risk factors for the development of dry eye after refractive surgery include older age and female gender.[112] Notably, dry eye symptoms tend to occur less often in PRK than in LASIK.[112] The alcohol-based technique for epithelial removal and the topical use of mitomycin-C have correlations with worse dry eye symptoms.[97][113] Treatment options for dry eye include artificial tears, punctal occlusion, omega-3 fatty acids, topical anti-inflammatory agents, and topical cyclosporine, available in doses ranging from 0.05% to 2%.[2][114]

Infection

Corneal infection and sterile infiltrates are rare early complications of laser refractive surgery. A 2017 study found that approximately 0.0013% of cases resulted in definite or probable microbial keratitis.[115] These conditions are typically apparent on postoperative days 2 to 4. Suspicion of ocular infection warrants a bacterial culture of the blood sample and corneal scraping. Corneal infections should be treated with topical fluoroquinolone eye drops every hour during the daytime, tapered according to clinical improvement; more severe infections may necessitate treatment with topical tobramycin 1.5% or cefazolin 5% every 30 minutes to 1 hour. Sterile infiltrates should be treated with prednisolone acetate eye drops.[21]

Re-epithelialization is typically complete by postoperative day 3. Delayed epithelial healing presents symptomatically as persistent blurred vision and, on slit-lamp examination, as epithelial defects with well-defined borders. If the surface remains intact by postoperative day 4, all medications except for the topical antibiotic should be discontinued, and the bandage soft contact lens should be replaced. Topical steroids may be restarted once epithelialization is complete.[21] Intraoperative mitomycin-C has correlated with delayed epithelial healing.[116]

Pseudodendrites are considered a regular part of the healing response and should not be confused with dendrites seen in herpes simplex keratitis. Pseudodendrites typically appear on postoperative day 3 or 4 and may cause blurring of vision if present in the visual axis. As they are part of the typical healing pattern and generally self-resolve within a matter of days, no changes in treatment are warranted.[21]

Halo Effect

Patients may experience a halo effect during the first 4 to 6 weeks following PRK, as the epithelium continues to heal. This phenomenon is more likely to occur at night when pupillary dilation allows for the transmission of light at the edge of the ablation zone. This symptom tends to diminish with time and generally does not warrant a change in treatment. Pilocarpine drops may be administered to promote pupillary constriction, but many patients do not tolerate these drops well.[117]

Central Corneal Islands

The formation of central islands along the cornea is an incompletely understood and likely multifactorial complication that may result in blurred vision. Central islands may be visible as small central shadows on retinoscopy, and diagnostic confirmation is provided by computed videokeratography, which shows elevations within the central or pericentral zone. Theorized causes of central island formation include emission of debris during laser ablation that interferes with laser pulses, uneven intraoperative corneal surface hydration that reduces central corneal ablation rate, and a higher degree of postoperative epithelial hyperplasia in the central cornea. Notably, the incidence of central islands following PRK has significantly decreased with the advent of new technology specifically designed to prevent their formation.[118] Central island formation is preventable by producing additional pulses to the central 2.5-mm area. Central islands tend to disappear within months but may be removed by the excimer laser if persistent after 6 to 12 months.[119]

Ectasia

Ectasia is an infrequent complication in the modern era due to strict adherence to the inclusion criteria, technical improvements in the excimer laser, and increased ability to interpret and assess preoperative surface data.[120] A retrospective study found the incidence of post-PRK ectasia to be 0.03%, and all noted cases occurred in individuals with underlying keratoconus.[121] The use of collagen crosslinking may prevent corneal ectasia in patients with keratoconus undergoing refractive surgery.[122]

Decentration

Decentration may occur due to poor pupil fixation and significant eye movements. Decentration may result in increased astigmatism, glare, haloes, and worse visual outcomes. Decentration tends to occur more often in eyes with higher attempted corrections due to the longer period required for fixation.[21] Rates of decentralization have decreased due to pupil tracking technology. Prevention of decerebration involves proper stabilization of the patient's head and stopping the procedure if the patient begins to lose fixation. If symptomatic, decentration treatment is possible with wave-guided enhancements.[123]

Corneal Erosion

Persistent corneal erosion is an early complication that presents as pain, tearing, and photophobia upon awakening. Corneal erosion tends to occur outside the area of ablation. Symptoms can be managed with hypertonic drops and ointment. If these do not succeed in reducing symptoms, placement of a bandage soft contact lens or phototherapeutic keratectomy (PTK) is another option.[30]

Corneal Haze

Corneal haze is a late complication that typically peaks in intensity at 1 to 2 months following laser refractive surgery and disappears within 6 to 12 months. Histological studies in animals and humans have demonstrated that haze is likely due to the migration of keratocytes and the deposition of abnormal glycosaminoglycans and non-lamellar collagen in the anterior stroma during the wound healing response.[124] Increased haze is related to the depth of laser ablation, epithelial removal technique, intraoperative corneal dryness, and homogeneity of the laser beam.[21] The risk of haze development is significantly higher in patients with hyperopia or high myopia.[125] The likelihood of haze development may be reduced by administering mitomycin-C 0.02% intraoperatively for 2 minutes or 2 to 4 times daily in the postoperative period for 1 to 4 weeks.[126] Moderate-to-severe haze that interferes with vision may be treated with topical steroid drops 5 times daily, which are tapered over 2 or 3 months with signs of clinical improvement.[21] Steroid drops decrease DNA synthesis and lens-specific antianabolic activity, thereby inhibiting keratocyte activity and collagen synthesis. Persistent haze lasting beyond 6 to 12 months may require treatment with topical mitomycin-C alone, superficial keratectomy, or PTK with or without mitomycin-C.[127] The application of a bandage soft contact lens is recommended, which should remain on the cornea until the underlying epithelial defect is completely resolved.

Persistent Refractive Errors

Persistent refractive errors may occur following laser refractive surgery due to undercorrection, overcorrection, or regression. Refractive errors are more likely to occur at higher corrections. Undercorrection may arise from insufficient initial treatment, significant myopic regression, or an excessively moist cornea during refractive surgery. Factors that promote regression include preoperative flat keratometry, small optical zones, steep wound edges, and secondary UV exposure.[21] Undesirable regression may be combated with aggressive use of topical steroids and wearing UV-protective sunglasses when exposed to sunlight at high altitudes for 6 months following laser refractive surgery. Conversely, overcorrection occurs due to an excessively dry cornea or preoperative assessment that fails to account for accommodation. A small amount of initial overcorrection is often considered acceptable, as regression occurs over time. Regression can be promoted by prolonged wear of a bandage soft contact lens or topical NSAID drops 4 times daily for 1 to 2 months.

Options for treatment of persistent refractive errors include further surface ablation, LASIK, and PTK, depending on the amount of desired correction, corneal thickness, and the amount of corneal haze. These enhancement procedures generally get delayed until a stable refraction is achieved for at least 3 to 6 months.[21] Patients with corneal haze should wait at least 6 to 12 months for symptoms to improve before enhancement surgery. Some authors have suggested using collagen crosslinking alone for the treatment of small amounts of residual refractive error, although this has not yet been researched as an option.[128]

Table 2. Complications of Photorefractive Keratectomy and Their Features

Abbreviations: NSAID, nonsteroidal anti-inflammatory drug; PRK, photorefractive keratectomy; BCL, bandage contact lens; RGP, rigid gas permeable; PTK, phototherapeutic keratectomy.

Clinical Significance

Long-term visual outcomes for patients who undergo PRK are generally excellent. A 15-year follow-up study of patients found that 55% of eyes were within ±1 D and 85% within ±2 D.[1] Technical improvements in the excimer laser, combined with the adoption of a peripheral transition zone, have enabled more predictable outcomes.

Systematic reviews comparing LASIK and PRK have demonstrated no differences in long-term efficacy, accuracy, or adverse outcomes in patients with low-to-moderate myopia.[129][130] However, LASIK tends to result in shorter recovery time and less postoperative pain.[131] There is a higher incidence of haze in PRK than in LASIK, likely due to the destruction of the basement membrane.[2] There is limited evidence to suggest whether LASIK or PRK is more beneficial for patients with hyperopia.

PRK is a widely established corneal refractive procedure that corrects myopia, hyperopia, and astigmatism by reshaping the anterior stromal curvature using an excimer laser. First introduced in the late 1980s, PRK is considered the progenitor of modern surface ablation techniques and has maintained a clinically significant role in refractive surgery, especially in selected patient populations. Although newer techniques, such as LASIK and SMILE, have emerged, PRK remains relevant due to its safety profile, suitability for thin corneas, and avoidance of flap-related complications.[3]

Alternative for Thin Corneas and Surface Irregularities

One of the most important clinical applications of PRK is in patients with thin corneas or irregular corneal surfaces where LASIK is contraindicated. LASIK requires the creation of a corneal flap, which can weaken structural integrity and increase the risk of ectasia in already thin corneas. PRK, by avoiding a stromal flap, preserves more corneal tissue, offering a safer alternative for patients with borderline corneal thickness, mild forme fruste keratoconus (under close monitoring), or those who have undergone prior corneal surgery.

Additionally, PRK has demonstrated utility in treating residual refractive error after corneal transplantation or radial keratotomy, where irregularity precludes safe flap creation. Surface ablation in such cases allows for predictable refractive enhancement with less disruption of corneal biomechanics.[132]

Absence of Flap-Related Complications

Unlike LASIK, PRK eliminates the risk of flap-related issues such as flap dislocation, striae, epithelial ingrowth, or traumatic flap complications. This advantage makes it particularly valuable for individuals in professions or sports with a high risk of ocular trauma, such as military personnel, martial artists, boxers, and firefighters. In these patients, avoiding a corneal flap significantly reduces the long-term risk of posttraumatic visual degradation.

Efficacy and Stability

PRK is a highly effective procedure with long-term stability and predictability. Numerous studies have reported comparable visual outcomes between PRK and LASIK. The mean postoperative uncorrected distance visual acuity (UDVA) typically reaches 20/20 or better in over 85% to 90% of patients undergoing PRK for low-to-moderate myopia. Moreover, refractive outcomes remain stable over time, particularly with the use of modern ablation algorithms and the application of mitomycin-C to reduce haze.[133]

Application in Refractive Enhancements

PRK is also used as a re-treatment option for patients with residual or recurrent refractive error following LASIK or other refractive procedures. As lifting a LASIK flap multiple times can weaken the cornea and increase the risk of complications, surface ablation with PRK becomes the preferred modality for safe enhancement. This approach is particularly useful in post-LASIK patients who experience myopic regression, epithelial ingrowth, or problems with the corneal flap interface.

Management of Epithelial and Superficial Stromal Disorders

PRK can serve a dual purpose in patients with recurrent corneal erosions, anterior basement membrane dystrophy, or superficial corneal scars. The removal of abnormal epithelium and smoothing of the anterior stroma during PRK results in an improvement in corneal architecture and symptom relief. Therapeutic surface ablation has also been shown to be beneficial in some instances of Salzmann's nodular degeneration and mild anterior stromal haze.[134]

Role in Occupational Vision Correction

PRK is often preferred for individuals requiring high visual demands in environments where dry eye or flap-related issues are detrimental. For instance, astronauts, pilots, and divers benefit from PRK, as it avoids flap instability caused by pressure or environmental changes. Similarly, in patients at risk of severe dry eye following LASIK, especially postmenopausal women, PRK has a lesser impact on corneal nerves and tear film stability.

Improved Safety with Mitomycin-C

The use of mitomycin-C during intraoperative procedures is a significant advancement that has enhanced the safety of PRK. Mitomycin-C significantly reduces the incidence of postoperative haze, especially in higher myopic corrections (>6 D), which was a significant limitation of early PRK techniques. The incorporation of mitomycin-C has expanded the applicability of PRK to higher refractive errors with improved outcomes and patient satisfaction.[135]

Fewer Biomechanical Alterations

PRK causes less biomechanical disruption of the cornea compared to LASIK and SMILE. Preserving corneal integrity is crucial for maintaining normal corneal curvature and preventing progressive ectasia, making PRK a safer option in patients at marginal risk of corneal instability and enhancing long-term visual safety.

Considerations in Healing and Visual Recovery

Although PRK offers multiple clinical advantages, its significance must also be viewed in light of delayed visual recovery and postoperative discomfort, which are more pronounced compared to LASIK. The epithelial healing time in PRK averages 3 to 5 days, and patients may experience photophobia, pain, and fluctuating vision during the first postoperative week. However, with modern bandage contact lenses, pain control regimens, and faster epithelial healing, this has become more manageable.[136] Additionally, corneal haze, although largely controlled with mitomycin-C, remains a potential complication that must be closely monitored in the early postoperative months, especially in high refractive corrections or cases involving UV exposure.

Cost-Effectiveness and Accessibility

PRK is generally less expensive compared to LASIK, as it avoids the creation of a femtosecond or microkeratome flap, making PRK an attractive option for patients in resource-limited settings or in healthcare systems where cost containment is a priority. The simplicity of equipment and technique also allows PRK to be performed in a broader variety of clinical settings.[137]

Pediatric and Special Population Relevance

Though rarely performed in children, PRK has been explored in selected pediatric patients with anisometropic amblyopia unresponsive to conventional therapies. In such cases, PRK can equalize refractive error and promote binocularity. PRK may also be used in aphakic correction in patients unfit for intraocular lens implantation or spectacles.[138]

Global Perspective and Refractive Burden

From a public health standpoint, PRK contributes to the global initiative of reducing uncorrected refractive error, a significant cause of visual impairment. By providing a safe and effective solution that avoids complex technology, PRK has the potential to make refractive surgery more accessible in low- and middle-income countries. PRK remains a clinically significant refractive procedure due to its safety, versatility, and applicability in special populations. Despite the advent of newer technologies, PRK offers a unique advantage in thin corneas, high-risk occupations, irregular corneas, and enhancement settings. With improved safety profiles through adjuncts such as mitomycin-C and enhanced pain management, PRK remains a relevant and valuable tool in the refractive surgeon's armamentarium. For carefully selected patients, it provides excellent visual outcomes with preserved corneal integrity, reduced biomechanical disruption, and long-term refractive stability.[139]

 Table 3. Clinical Benefits of Photorefractive Keratectomy Versus Other Refractive Procedures

Abbreviations: PRK, photorefractive keratectomy; LASIK, laser in situ keratomileusis; SMILE, small incision lenticule extraction.

Table 4. Key Indications with Clinical Significance

Abbreviation: LASIK, laser in situ keratomileusis.

Table 5. Long-Term Visual Outcomes After Photorefractive Keratectomy

 Table 6. Clinical Significance in Special Populations

Abbreviations: PRK, photorefractive keratectomy.

Table 7. Mitomycin-C Use and Clinical Impact

Abbreviations: PRK, photorefractive keratectomy; PTK, phototherapeutic keratectomy.

Enhancing Healthcare Team Outcomes

An interprofessional team of ophthalmic surgeons, nurses, optometrists, and technicians may be involved in the preoperative evaluation, surgery, and postoperative care of patients who undergo PRK. Ensuring appropriate patient selection according to FDA and AAO guidelines and maintaining adequate follow-up are essential for maximizing long-term visual outcomes and patient satisfaction. Nurses should ensure that informed consent is obtained. If surgery is performed on one eye, the nurse must mark it before the procedure. Nurses also assist during the procedure and provide postoperative care, reporting all status changes to the surgeon. Before any anesthesia, a timeout should be called to verify the patient ID, name, and location of the surgery. All members of the team should be aware of clinical signs and symptoms suggestive of major postoperative complications, and prompt referral to a cornea specialist is warranted should any of these complications arise. Close communication between members of the interprofessional team is vital for improving outcomes.[140]

PRK, as a refractive surgical procedure, necessitates seamless collaboration across the healthcare continuum to optimize patient safety, satisfaction, and visual outcomes. Successful PRK outcomes are not solely dependent on the skill of the operating ophthalmic surgeon but also on a well-orchestrated, interprofessional team effort.[132]

Clinicians and surgeons are responsible for evaluating candidacy, managing expectations, performing the surgical procedure, and ensuring long-term follow-up. Coordinated assessments from optometrists and ophthalmic technicians inform their clinical decision-making. Optometrists play a crucial role in preoperative evaluation, postoperative monitoring, and assessing long-term refractive stability, ensuring early identification of complications such as haze or regression.[141]

Nurses and ophthalmic technicians play a critical role in patient preparation, perioperative education, and postoperative care. Their responsibilities include ensuring informed consent, preoperative antisepsis, and administering medications while addressing patient anxiety and supporting compliance. Pharmacists contribute by counseling patients on postoperative medication regimens—particularly steroids, NSAIDs, and antibiotics—thereby preventing adverse effects and promoting corneal healing.[142]

Interprofessional communication is vital throughout the perioperative period. Regular team briefings, shared electronic health records, and patient-centered discussions ensure that all healthcare professionals are aligned on the treatment plan. Patient safety is enhanced through standard operating protocols, double-check systems for medication dispensing, and meticulous documentation of surgical steps and visual outcomes.[143]

In addition, ethical considerations such as informed consent, patient autonomy in refractive choices, and transparency about risks and benefits are integrated into every stage of care, fostering trust and enhancing patient satisfaction. By fostering a collaborative team environment, PRK programs can achieve improved refractive outcomes, reduced complication rates, better medication adherence, and higher patient satisfaction. Ultimately, coordinated interprofessional efforts ensure not only the technical success of the procedure but also a holistic, patient-centered approach to visual rehabilitation.[144]

Nursing, Allied Health, and Interprofessional Team Interventions

Successful PRK outcomes depend on a coordinated, interprofessional approach involving nurses, optometrists, ophthalmic technicians, pharmacists, and primary care providers. Interprofessional collaboration ensures safe perioperative care, patient education, and timely management of complications. Key responsibilities and contributions of each team member are discussed below.[69]

Nurses

• Preoperative assessment and counseling: Nurses evaluate baseline ocular and systemic health, confirm informed consent, and reinforce expectations, including pain and delayed visual recovery.
• Medication administration: Nurses ensure the proper instillation of prophylactic antibiotics, NSAIDs, and anesthetic drops before and after surgery.
• Patient education:
  • Instructions regarding medication adherence (especially topical steroids and lubricants).
  • Use of protective eye shields at night.
  • Importance of follow-up visits and avoiding eye rubbing.

• Pain management: Monitoring postoperative discomfort and guiding use of oral analgesics or cold compresses.
• Infection control: Educating about hygiene during epithelial healing (first 3-5 days), signs of infection, and when to report symptoms.[145]

Optometrists

• Preoperative evaluation:
  • Refractive error assessment, topography, pachymetry, and tear film evaluation.
  • Determining candidacy by identifying contraindications (eg, keratoconus and dry eye).

• Postoperative monitoring:
  • Detecting complications such as haze, regression, or epithelial healing issues.
  • Adjusting refractions and helping with visual rehabilitation or temporary corrective aids.[146]

Ophthalmic Technicians

• Diagnostic testing:
  • Accurate corneal topography, wavefront aberrometry, and anterior segment photography.

• Surgical preparation:
  • Sterile preparation of the eye.
  • Assisting with the calibration and settings of the excimer laser.

• Documentation: Recording intraoperative parameters and outcomes for audits and patient records.[64]

Pharmacists

• Medication review:
  • Screening for drug allergies and interactions, especially NSAIDs or corticosteroids.

• Ensuring availability and compliance:
  • Providing clear instructions on tapering steroid schedules.
  • Recommending preservative-free lubricants and handling analgesic regimens appropriately.

• Patient counseling:
  • Reinforcing the importance of compliance with anti-inflammatory therapy to prevent haze.[147]

Primary Care Physician/General Practitioner

• Systemic health optimization:
  • Ensuring that systemic conditions such as diabetes mellitus or autoimmune diseases are well-controlled before surgery.

• Postoperative coordination:
  • Managing any systemic adverse effects of medications, such as corticosteroids.
  • Providing additional pain or anxiety relief if required.[148]

Interprofessional Communication and Coordination

• Shared decision-making: Team collaboration during preoperative counseling supports informed consent and realistic expectations.
• Electronic health records: Secure, timely documentation of patient progress and shared alerts on red-flag symptoms (eg, delayed epithelial healing and corneal haze).
• Continuing education: Regular interprofessional continuing medical education updates on refractive surgery techniques and safety protocols.

Ethical and Patient-Centered Considerations

• Respect for autonomy: Empowering patients with complete information about alternatives to PRK (eg, LASIK and SMILE).
• Informed consent: Ensuring the patient comprehends benefits, limitations, recovery time, and potential for enhancements.
• Equity in access: Ensuring that refractive surgery is accessible irrespective of socioeconomic background when offered in public health settings.

The success of PRK hinges not only on the surgeon's precision but also on the synergy among interprofessional team members. Through coordinated care, education, and timely follow-up, the team enhances patient outcomes, reduces complications, and improves satisfaction in refractive surgical care.[149]

Nursing, Allied Health, and Interprofessional Team Monitoring

Postoperative monitoring after PRK is essential for ensuring epithelial healing, managing complications, and optimizing refractive outcomes. This process requires coordinated interprofessional engagement, where nurses, optometrists, technicians, pharmacists, and ophthalmologists share responsibilities in an integrated follow-up framework.[150]

Nursing Monitoring

• Daily symptom assessment: Monitoring pain, photophobia, tearing, and visual acuity changes during the first 5 to 7 days.
• Epithelial healing monitoring: Checking bandage contact lens fit and observing for signs of delayed epithelialization.
• Red flags for infection or inflammation:
  • Pain not responding to analgesics.
  • Discharge or worsening redness.
  • Corneal infiltrates or epithelial defects.

• Monitoring medication compliance:
  • Ensuring adherence to the antibiotic-steroid-lubricant regimen.
  • Documenting tapering of topical steroids to prevent haze.

• Patient's emotional status:
  • Offering reassurance about fluctuating vision.
  • Coordinating referrals to counseling in cases of anxiety or unrealistic expectations.[151]

Optometrist Monitoring

• Visual acuity and refraction follow-up:
  • Serial uncorrected and best-corrected visual acuity recordings.
  • Monitoring for regression or residual refractive error.

• Corneal clarity evaluation:
  • Identifying the grade of subepithelial haze using slit-lamp biomicroscopy.

• Wavefront aberration monitoring:
  • Postoperative assessment of higher-order aberrations is indicated.

• Dry eye and tear film status:
  • Monitoring for ocular surface disruption or evaporative dry eye syndrome.[152]

Ophthalmic Technician Role in Monitoring

• Ocular imaging support:
  • Performing serial corneal topography and anterior segment photos.
  • Assisting with epithelial defect size documentation.

• Bandage contact lens monitoring:
  • Evaluating centration and tightness of lenses.
  • Coordinating removal timing (typically postoperative day 4-7).[153]

Pharmacist Monitoring

• Drug adverse effect surveillance:
  • Detecting adverse reactions to NSAIDs (eg, corneal melts).
  • Ensuring no systemic contraindications with oral analgesics or antibiotics.

• Steroid taper monitoring:
  • Reviewing the prescribed tapering plan to minimize haze risk.
  • Encouraging preservative-free formulations in sensitive patients.[154]

Table 8. Interprofessional Monitoring Protocol

Communication and Documentation

• Utilizing electronic medical records to track symptom trends, medication logs, and interprofessional notes.
• Telephonic or telehealth check-ins by nurses/optometrists for patients in remote locations.
• Escalation protocols for early referral to ophthalmologists if warning signs arise (eg, keratitis, central haze, and persistent pain).

Comprehensive monitoring after PRK is best achieved through a structured, team-based approach. Each professional contributes specialized oversight to enhance safety, minimize complications, and optimize visual outcomes. Strong communication, early detection of complications, and timely interventions form the backbone of successful PRK recovery.[155]