Refractive Outcomes of Topography-Guided Photorefractive Keratectomy With Simultaneous CXL for Keratoconus
Narrative Responses:
Purpose
To evaluate efficacy and safety of topography-guided photorefractive keratectomy (TG-PRK) with collagen cross-linking (CXL) for keratoconus (KC
Methods
Retrospective case series of 365 eyes with contact lens (CL) intolerant KC undergoig TG-PRK with Allegretto Wavelight (AW) laser using Topographic Neutralization with simultaneous CXL. Epithelial removal by trans-epithelial laser, riboflavin 0.1% until aqueous staining, UV irradiation 370nm for 8-15 minutes at 3mW/cm2 - 5.4 J/m2. Refractive correction planned to leave residual stromal depth of 300 microns with target correction of -1.25 diopters(D). Symptom score (10 point), uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), efficacy, and safety were evaluated at 12 months
Results
165 eyes completed 12 months follow-up. 82 eyes (49%) had UCVA of 20/40 or better. 26 eyes (16%) had UCVA of 20/25 or better. 81 eyes (49%) had BSCVA improved, 45 eyes (27%) gained 2 lines or more, 5 eyes (4%) lost 2 lines or more. Average symptom score improved from 6.7 to 4.2 Mean reduction of astigmatism was 1.52 diopters (D). . Complications included 7 with delay in epithelial healing, 4 with subsequent haze, 2 sufficient to reduce BCVA more than 2 lines, with one undergoing keratoplasty. One developed herpetic keratitis recovering pre-operative BCVA after PTK.
Conclusion
Satisfactory efficacy and safety were achieved after simultaneous topography-guided PRK with CXL. At one-year follow-up, almost half achieved UCVA of 20/40 or better with one third improving 2 or more lines of BSCVA. The combined technique of CXL with customized TG PRK offers promising results for CL-intolerant KC patients.