Evaluation of long-term outcomes of simultaneous corneal collagen cross-linking and femtosecond laser-assisted intracorneal ring segment implantation for keratoconus

Background Intracorneal ring segment (ICRS) implantation in combination with corneal collagen cross-linking (CXL) has shown promising results in improving the visual acuity and reducing refractive errors, but long-term results are lacking. Aim To evaluate the long-term outcomes (> 5 years) of simultaneous CXL and femtosecond laser-assisted intracorneal stromal ring segment implantation for management of keratoconus. Design This was a noncomparative, noncontrolled retrospective single-center study. Patients and methods The study included 50 eyes of 37 patients with keratoconus who underwent simultaneous CXL and ICRS implantation and were followed up for at least 5 years regarding visual acuity, refraction, and corneal imaging. Results Best-corrected visual acuity showed statistically significant improvement, with mean changed from 1.07 +/- 0.41 to 0.40 +/- 0.30 LogMAR. The results showed significant improvement also after 5 years. The spherical equivalent also was significantly improved from a mean of -4.61 +/- 4.37 D to a mean of -1.41 +/--1.49 D. Keratometric readings also showed improvement of both K1 and K2. The mean K1 improved from a mean of 49.6 +/- 6.76-47.78 +/- 6.17 D, and the mean K2 improved from 55.04 +/- 7.34 to 52.67 +/- 7.38. The results were stable, with no statistically significant change after 5 years. Conclusions Simultaneous CXL and femtosecond laser-assisted ICRS is effective and stable for both visual outcome and refraction in patients with keratoconus.