Visual and Refractive Outcomes and Tomographic Changes of One Segment Femtolaser Assisted Intrastromal Corneal Ring Implantation based on severity of Keratoconous

Purpose: To assess the visual and refractive outcomes and tomographic changes after femtosecond laserassisted implantation of a single-segment intrastromal corneal ring (ICRS; Intacs® SK) in the early stages of Keratoconous. Methods: In retrospective interventional case series study; One segment Intacs SK ICRS was inserted using a femtosecond laser into eyes with stage I–II Keratoconous. Visual and refractive outcomes and corneal tomography changes were analyzed 1 week, 2 and 6 months postoperatively. Results: The study evaluated 155 eyes of 123 patients (mean age: 31.3 years). At six months post operation, the spherical equivalent, mean sphere, and mean cylinder were decreased by 0.97, 1.22, and 1.29 diopters (D), respectively. The mean preoperative uncorrected (UDVA) and corrected distance visual acuity (CDVA) increasedfrom 0.78 ± 0.20 to 0.39 ± 0.21 and from 0.45 ± 0.18 to 0.18 ± 0.14 LogMAR (P < 0.001), respectively. Steep and Flat Keratometry, Mean K and anterior and posterior best feet sphere decreased significantly (P < 0.001). Among all eyes, 94.0% gained one or more lines of CDVA. Mean internal anterior chamber depth decreased from 3.21 ± 0.33 to 3.12 ± 0.33 mm (P = 0.001), and mean irregularity in the 3 mm zone decreased from 4.74± 1.68 to 3.89 ± 1.24 (P <0.000).Conclusion: Implantation of one segment Intacs SK is safe and effective to treat Keratoconous, especially in stage I-II, leading to significant improvement in UDVA, CDVA, and refractive error.