Long-Term Outcomes of a 360-Degree Intracorneal Ring Implantation for Keratoconus: A 10-Year Follow-Up

PURPOSE: To evaluate the long-term visual, refractive, and tomographic outcomes of a 360-degree intracorneal ring implant for treating keratoconus (KC). METHODS: This historical cohort study included 29 eyes of 29 patients with KC who underwent MyoRing implantation. Uncorrected and best-corrected distance visual acuity, refraction, keratometry, and corneal thickness were evaluated preoperatively and at 5 and 10 years postoperatively. RESULTS: Significant improvements were observed in all outcome measures at 5 and 10 years postoperatively compared with the preoperative values ( P < 0.001). Uncorrected distance visual acuity improved from 1.25 ± 0.34 logarithm of the minimum angle of resolution (logMAR) preoperatively to 0.36 ± 0.24 logMAR at 5 years but showed regression to 0.48 ± 0.35 logMAR at 10 years. Corrected distance visual acuity similarly showed improvement from 0.50 ± 0.24 logMAR preoperatively to 0.18 ± 0.12 logMAR at 5 years, with some regression to 0.25 ± 0.22 logMAR at 10 years. Spherical equivalent improved from -9.38 ± 4.09 diopters (D) preoperatively to -2.70 ± 1.54 D at 5 years but regressed to -3.29 ± 2.22 D at 10 years. Although corneal flattening was observed at 5 years, a slight steepening trend was noted at 10 years. Corneal thickness exhibited an increase after 5 years ( P < 0.001), but this trend reversed by the 10-year mark. CONCLUSIONS: MyoRing implantation demonstrated significant initial improvements in visual, refractive, and tomographic outcomes in patients with KC; however, some regression toward preoperative values was observed by the 10-year follow-up. This highlights the importance of continued monitoring to assess the long-term impact of the implant and to manage any potential late effects.