Purpose: To evaluate the initial outcomes of femtosecond intrastromal lenticular implantation (FILI) combined with accelerated collagen cross-linking in patients with progressive keratoconus.
Methods: In this interventional, prospective, exploratory case series, patients with progressive keratoconus and contact lens intolerance were included. All eyes underwent femtosecond laser-enabled placement of stromal donor tissue and simultaneous accelerated collagen cross-linking. Follow-up of patients was conducted for a mean period of 190 ± 13 days (range, 177-193 days).
Results: Six eyes from 6 patients were included in the study. Based on values before and 6 months after the procedure, clinical improvement was noted in uncorrected distance visual acuity (1.06 ± 0.48 logMAR vs. 0.38 ± 0.27 logMAR), corrected distance visual acuity (0.51 ± 0.20 logMAR vs. 0.20 ± 0.24 logMAR), and manifest spherical equivalent (-3.47 ± 1.15 D vs. -1.77 ± 1.7 D). There was flattening of mean keratometry in 3-mm and 5-mm zones by 3.42 ± 2.09 D and 1.70 ± 1.31 D, respectively. Mean pachymetry in the central and midperipheral zones increased by 18.3 ± 7.3 μm and 33.0 ± 8.8 μm, respectively. All eyes had reduction in higher-order aberrations, specifically coma. No eye lost lines of corrected distance visual acuity. No adverse events such as haze, infection, or allogeneic graft rejection were observed.
Conclusions: Initial experience with this small number of eyes suggests that the combination of tissue addition and accelerated collagen cross-linking may be a feasible option for low to moderate keratoconus. A larger cohort and longer follow-up are required to validate our results and establish long-term safety and efficacy of the procedure.