Best Photorefractive Keratectomy (PRK) Treatment Approach
For refractive correction, wavefront-guided PRK using modern excimer laser platforms is the optimal approach, demonstrating superior safety and efficacy with 96.6% of eyes achieving within ±1.00 D of intended correction at 12 months. 1
Primary Treatment Strategy
Standard PRK for Refractive Errors
Wavefront-guided PRK should be the preferred technique for treating low to moderate myopia (-0.125 to -6.50 D) and high myopia (≥-6.50 D), achieving safety and efficacy indexes of 1.01 and 1.02 respectively at 12 months 1
The treatment demonstrates excellent predictability with 81.5% of eyes within ±0.50 D of intended correction at one year 1
For myopic astigmatism, PRK successfully corrects both spherical and cylindrical components, with 73% of astigmatism corrected at 6 months and 94% at 1 year 2
Surface Ablation for Corneal Aberrations
When treating corneal aberrations or irregularities, phototherapeutic keratectomy (PTK) is the most effective approach for anterior corneal pathology limited to the anterior 10-15% of stromal thickness. 3
PTK improves epithelial stability and visual acuity in conditions including epithelial basement membrane dystrophy, bullous keratopathy, and anterior stromal scarring 3
Apply mitomycin-C (MMC) as an adjunct to PTK to reduce risk of haze and recurrence, especially for deeper ablations 4, 3
MMC should be applied on a circular sponge to the corneal stroma after laser treatment, followed by copious irrigation to reduce toxicity risk 3
Combined Procedures
PRK with Corneal Cross-Linking (CXL)
Combining CXL with PRK has been proposed to stabilize the cornea while improving visual function in ectatic conditions 5
However, simultaneous procedures carry substantial concerns: CXL alone induces changes in anterior corneal curvature that don't stabilize until 6-12 months postoperatively 5
Increased risk of stromal haze after simultaneous combined procedures remains a major concern, and the exact sequence (simultaneous vs. sequential) and long-term safety remain undetermined 5
Special Clinical Applications
Accommodative Esotropia
PRK effectively treats purely refractive accommodative esotropia in young adults with mild to moderate hyperopia 6
All patients achieved orthophoria without correction postoperatively, with mean esotropic deviation reducing from 10.75 prism diopters preoperatively to zero 6
Critical caveat: These findings should not be widely applied to children with accommodative esotropia 6
Management of PRK Complications
Retreatment Strategies
There is no single gold standard for retreatment after PRK—the surgeon must consider patient history and specific problem type when selecting the appropriate technique. 7
For residual refractive error: Both LASIK and repeat PRK are viable options 7
For corneal haze: Treat with phototherapeutic keratectomy combined with mitomycin-C, which produces good results 7
For high-order aberrations and decentration: Use topographically-guided excimer photoablation or wavefront-guided PRK 7
Critical Technical Considerations
Surface Irregularity Management
When treating irregular surfaces with PTK, use a masking agent (methylcellulose or sodium hyaluronate) to fill valleys so peaks can be ablated first, preventing etching of surface topography into underlying layers 3
Post-PTK complications including hyperopic shift and surface irregularity should be monitored, as treatment to deeper levels is associated with higher-order aberrations and irregular astigmatism 3
Depth Limitations
Limit PTK treatment to the anterior 10-15% of stromal thickness when possible to avoid significant hyperopic shift and irregular astigmatism 3
For deeper stromal aberrations, consider anterior lamellar keratoplasty (ALK) instead, which can achieve smoother results when performed using microkeratome or femtosecond laser 3
Key Pitfalls to Avoid
Overtreatment with PTK leads to significant hyperopic shift and irregular astigmatism 3
Inadequate mitomycin-C management can cause stromal melt and ocular surface toxicity—copious irrigation after application is essential 3
Ignoring biomechanical impact of deeper treatments can lead to progressive ectasia—always assess corneal thickness and topography before treatment 3
Delayed treatment timing in certain conditions (such as interstitial lung disease with basilar opacities, though not directly related to PRK) demonstrates the importance of early intervention when indicated 8