Two-Staged Sequential Management of Post-LASIK Ectasia: Under-Flap Corneal Cross-Linking for Stabilization Followed by Flap Surface Topography-Guided PRK for Visual Optimization

Abstract

Background/Objectives: To evaluate the efficacy, accuracy, safety, and long-term stability of topography-guided photorefractive keratectomy (TGPRK) in eyes where post-LASIK (PLE) ectasia progression was stabilized with under-flap corneal crosslinking (ufCXL). Methods: This retrospective interventional case series included six eyes from five patients with PLE after microkeratome LASIK. All eyes underwent ufCXL to halt ectatic progression. A shallow TGPRK enhancement was performed on the LASIK flap surface after corneal and refractive stability was confirmed (18 months median) post ufCXL Outcome measures included uncorrected and corrected distance visual acuity (UDVA, CDVA), spherical equivalent (SEQ), refractive astigmatism, keratometry, and corneal irregularity indices over a mean follow-up of 47 months. Results: ufCXL stabilized ectatic progression but left residual refractive errors, limiting UDVA. TGPRK performed subsequently significantly improved UDVA, from 0.38 to 0.10 LogMAR (p = 0.017), and increased the LASIK efficacy index from 0.46 to 0.83 (p = 0.0087). Refractive astigmatism was reduced in all eyes achieving a SEQ within ±1.00 D of the target. Long-term stability was maintained, with no ectasia progression, no change in SEQ, no change in corneal irregularity indices, and no increase in maximal keratometry. Conclusions: TGPRK performed in ufCXL stabilized corneas can safely correct residual refractive errors, resulting in significant and sustained improvements in both refractive and visual outcomes in PLE.

Keywords

• LASIK
• Coneal Ectasia
• under-flap CXL
• topography-guided
• PRK