Comparison of t-PTK + CXL and CXL with mechanical debridement for keratoconus: fellow eye study.

PURPOSE: To compare visual, refractive, tear function, and ocular surface outcomes of accelerated corneal cross-linking (CXL) performed with transepithelial phototherapeutic keratectomy (t-PTK) versus mechanical epithelial debridement in fellow eyes of patients with keratoconus.

METHODS

This retrospective, comparative, fellow-eye study included 52 eyes of 26 keratoconus patients, each with a thinnest corneal thickness greater than 450 µm before the procedure, who underwent accelerated CXL with two different epithelial removal techniques. One eye received t-PTK-assisted epithelial removal and the fellow eye mechanical debridement. Corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UCVA), refractive and topographic parameters, higher-order aberrations (HOAs), tear function tests, pain scores, epithelial healing time, and demarcation line depth were assessed up to 12 months postoperatively.

RESULTS

Epithelial healing time and pain scores were comparable between groups (p > 0.05). Demarcation line depth and endothelial cell counts showed no significant difference. At postoperative month 12, the t-PTK group demonstrated significantly improved CDVA and UCVA, reduced spherical equivalent, keratometric values, corneal astigmatism, and total HOAs, whereas no significant improvements were observed in the mechanical group. Tear break-up time significantly decreased in both groups, while Schirmer test results and corneal staining remained unchanged. No significant haze was detected in either group.

CONCLUSION

While epithelial healing, ocular surface parameters, and safety outcomes were similar between techniques, t-PTK-assisted epithelial removal provided superior long-term visual, refractive, and topographic improvements compared with mechanical debridement. Accelerated CXL following t-PTK may offer enhanced therapeutic benefit for selected keratoconus patients.