Accelerated CXL Versus Accelerated Contact-Lens Assisted CXL Treatment for Progressive Keratoconus—A 3-Year Retrospective Comparative Follow-Up

Background: Contact lens-assisted corneal cross-linking can be used to treat keratoconus in patients with thin corneas under measuring less than 400 µm. This study compares the long-term clinical and tomographic outcomes between accelerated corneal cross-linking (A-CXL) and accelerated contact lens-assisted corneal cross-linking (A-CACXL). Methods: Patients who underwent either A-CXL or A-CACXL protocol due to progressive keratoconus were enrolled in this retrospective cohort study conducted between January 2015 and December 2018. The control group (patients with minimum corneal thickness of at least 400 µm, comprising 32 eyes of from 32 patients) was treated with A-CXL, whereas the treatment group (patients that had minimum corneal thickness after epithelial removal below 400 µm; 30 eyes of from 30 patients) underwent the A-CACXL protocol. Clinical and tomographic data were obtained from a 3-year follow-up period. Results: At 3 years, both groups represented a significant gain in best-corrected visual acuity (from 0.32 to 0.18 LogMAR units for A-CXL, p = 0.001; from 0.51 to 0.33 LogMAR units for A-CACXL, p = 0.037). Furthermore, postoperative tomographic parameters (Kmax, Kmean, or corneal astigmatism) were comparable between the two protocols. Progression of keratoconus was halted among 87% of eyes in the A-CXL group and among 73% of eyes in the A-CACXL group (p = 0.2). Conclusions: A-CACXL treatment is an effective and safe option for patients with keratoconus and thin corneas, yielding long term outcomes comparable to those of A-CXL treatment for patients with a minimum corneal thickness of 400 µm following a 3-year follow-up.