Refractive lenticule-assisted accelerated corneal cross-linking: a three-year clinical observation in patients with thin keratoconus

Abstract

Objective: Accelerated corneal cross-linking (A-CXL) is unsuitable for the treatment of thin keratoconus. We developed a technique termed Refractive Lenticule-assisted Accelerated Corneal Cross-Linking (RLA-ACXL) by overlaying lenticules during A-CXL to optimize therapy for thin keratoconus. This retrospective study evaluates the 3-year efficacy and safety of RLA-ACXL.

Methods: This study retrospectively included 63 eyes (from 42 patients) with progressive keratoconus who underwent A-CXL in our hospital from September 2017 to December 2020. The surgical method was determined based on corneal thickness. Patients who received RLA-ACXL (10 patients with 18 eyes) were designated as Group A, while those who underwent A-CXL alone (32 patients with 45 eyes) were classified as Group B. Both groups were followed for 3 years. Preoperative and postoperative evaluation (conducted at 6, 12, 24, and 36 months) included best corrected visual acuity (BCVA), endothelial cell density (ECD), thinnest corneal thickness (TCT), keratoconus vertex back (Kvb), and corneal curvature. Any adverse events occurring during follow-up, such as delayed corneal healing, infection, or haze, were recorded.

Results: Throughout the follow-up period, no significant changes were observed in TCT, Kmax, K1, K2, or Kvb in Group A. However, BCVA improved significantly by 36 months postoperatively (P < 0.05), and ECD showed a significant increase at the 12-month mark (P < 0.05). In the same period, Group B showed decreases in TCT and ECD compared to baseline (P < 0.05), along with increases in anterior surface K1 and K2 values, and improvements in BCVA and Kmax (P < 0.05). No significant change in Kvb was observed. Both groups exhibited uneventful healing with no adverse events. Notably, during the 12-month postoperative period, Group A exhibited more significant thickening of Kvb, greater decreases in TCT and K1, and more pronounced ECD recovery compared to Group B. During the 36-month follow-up, Group A exhibited more substantial improvements in BCVA and a more pronounced elevation in Kvb.

Conclusions: Over the 3-year follow-up period, RLA-ACXL and A-CXL showed similar efficacy and safety in controlling the progression of keratoconus.

Keywords: A-CXL; Accelerated corneal cross-linking; Progressive keratoconus; Refractive lenticule; Refractive lenticule-assisted accelerated corneal cross-linking; SMILE; Small incision lenticule extraction; Ultrathin cornea.