Long-Term Follow-Up of a 150° Arc-Length Intrastromal Corneal Ring Segment Implantation in Post-LASIK Ectasia

PurposeTo evaluate the outcomes of implanting a 150 degrees arc-length intrastromal corneal ring segment (ICRS) using a femtosecond laser in patients with post-LASIK ectasia throughout a 5-year follow-up period.MethodsThis study enrolled 45 eyes of 45 patients diagnosed with post-LASIK ectasia who underwent a 150 degrees arc-length Ferrara-type ICRS implantation. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, residual refractive errors, and root mean square (RMS) for coma-like aberration were evaluated preoperatively and at 6-, 12-, 36, and 60 months postoperatively.ResultsMean UDVA (logMAR) ameliorated from 0.53 +/- 0.33 preoperatively to 0.26 +/- 0.24 at 6 months postoperatively (p < 0.0001). Mean CDVA improved from 0.12 +/- 0.13 to 0.04 +/- 0.06 (p < 0.0001). Mean UDVA and CDVA remained stable throughout the 5-year follow-up (p > 0.1). No eyes lost lines of CDVA at any follow-up visit compared to preoperatively, and most eyes gained lines. The eyes with a refractive cylinder <= 2.00 D varied from 26.7% preoperatively to more than 75% at all postoperative follow-up visits. The maximum keratometry was significantly flattened (p < 0.0001), and the RMS for corneal coma-like aberration was halved (p < 0.0001). 93.3% of the eyes did not show signs of disease progression or regression of the visual or refractive outcomes at any follow-up visits.ConclusionThese results suggest that implanting a single 150 degrees arc-length Ferrara-type ICRS is a safe, effective and stable procedure for visual restoration in post-LASIK ectasia. In very few cases, visual and/or refractive instability was experienced throughout the follow-up.

Automated summary

This study evaluated the outcomes of implanting a 150 degrees arc-length intrastromal corneal ring segment (ICRS) in patients with post-LASIK ectasia. The results showed that the procedure was safe, effective, and stable, leading to visual restoration in these patients.