Corneal cross-linking in thin corneas: 1-year results of accelerated contact lens–assisted treatment of keratoconus

PURPOSE: To evaluate the safety and efficacy of accelerated contact lens–assisted cross-linking (A-CACXL) for patients with keratoconus and thin corneas. METHODS: This retrospective study included consecutive patients undergoing A-CACXL for progressive keratoconus from 2015 to 2017. Patients with a minimum corneal thickness of 400 µm or less after epithelium removal who underwent A-CACXL (9 mW/cm² for 10 minutes, using iso-osmolar 0.1% riboflavin solution and a 90-µm thick, daily disposable bandage soft contact lens) with a follow-up time of 12 months or more were included. The main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuity and minimum corneal thickness at the last visit. Progression (increase) and flattening (decrease) were defined as a change of 1.00 diopters (D) or greater in maximum keratometry or 1.50 D or greater in mean keratometry. RESULTS: Overall, 24 eyes of 24 patients were included with a follow-up time of 18.2 ± 6.3 months and a mean minimum corneal thickness, after epithelial debridement, of 353.13 µm. There was a significant improvement in UDVA (P = .009), maximum keratometry (P = .03), anterior steep keratometry (P = .04), anterior astigmatism (P = .02), and posterior astigmatism (P = .04) with no significant change in minimum corneal thickness (P = .11). There was a significant improvement in UDVA (0.90 ± 0.63 to 0.64 ± 0.47 logMAR, P = .009), maximum keratometry (61.20 ± 6.30 to 59.90 ± 5.70 D, P = .03), anterior steep keratometry (55.10 ± 3.90 to 54.50 ± 4.10 D, P = .04), anterior astigmatism (5.50 ± 2.40 to 4.60 ± 2.10 D, P = .02), and posterior astigmatism (0.90 ± 0.40 to 0.80 ± 0.40 D, P = .04) with no significant change in minimum corneal thickness (from 399.8 ± 30.7 to 391.0 ± 43.8 μm, P = .11). Flattening occurred in 45.8% (n = 11) and progression in 20.8% (n = 5). There were no serious adverse events. Persistent clinically significant stromal haze occurred in one case and completely resolved by 6 months. There was no significant change in endothelial cell density (P = .10). CONCLUSIONS: In patients with keratoconus and thin corneas, A-CACXL halted keratoconus progression in 80%, led to flattening in 45%, and significantly improved UDVA and keratometry values without any evidence of damage to the corneal endothelium or permanent adverse events.