Long-Term Follow-up of Intrastromal Corneal Ring Segment Implantation in Pediatric Keratoconus

Purpose: To evaluate efficacy, safety, and stability of Ferrara-type intrastromal corneal ring segment (ICRS) implantation for visual rehabilitation in pediatric patients with keratoconus. Methods: This study included patients with keratoconus aged 18 years or younger who had received Ferrara-type ICRS implantation. The uncorrected and corrected distance visual acuities, residual refractive errors, and root mean square for coma-like aberration were recorded preoperatively and at 6 months, 1, 3, and 5 years postoperatively. Results: One hundred eighteen eyes of 88 patients (mean age 16.1 ± 1.89; range 10–18) were studied. All patients were examined at a 6-month follow-up after ICRS implantation, and at the 12-, 36-, and 60-month follow-ups, 97, 71, and 23 eyes were evaluated, respectively. Mean uncorrected distance visual acuity (logarithm of minimum angle of resolution) changed from 0.67 ± 0.37 preoperatively to 0.37 ± 0.30, 6 months after ICRS implantation (P < 0.0001). Mean corrected distance visual acuity increased in turn from 0.19 ± 0.15 to 0.10 ± 0.12 (P < 0.0001). The percentage of eyes with a refractive cylinder ≤2.00 D increased from 30.5% before surgery to 70.3% 6 months later, and the root mean square for corneal coma-like aberration showed a statistically significant decrease (P < 0.001). At the follow-up visits, refractive and visual values remained stable compared with those of the 6-month visit. Conclusions: Our long-term results suggest that Ferrara-type ICRS implantation is a safe, effective, and stable procedure for restoring vision in pediatric patients with keratoconus