Intracorneal ring segment implantation for the management of keratoconus: Safety and efficacy

Abstract

PURPOSE: To assess the safety and efficacy of intracorneal ring segment (Intacs, Addition Technology, Inc.) implantation in the management of keratoconus. SETTING: Department of Ophthalmology and Ophthalmic Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran. METHODS: This prospective case series comprised 30 keratoconic eyes (22 patients) with a clear central cornea that had Intacs implantation. All patients were contact-lens intolerant. The main outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, keratometry, and pachymetry. Patients were examined before Intacs implantation as well as 1 week and 1, 3, and 6 months postoperatively. RESULTS: The mean age of the 5 women and 17 men was 25.9 years ± 5.29 (SD). The mean UCVA improved from 0.60 ± 0.311 logMAR preoperatively to 0.29 ± 0.20 logMAR 6 months postoperatively (P<.001) and the mean BSCVA, from 0.25 ± 0.16 logMAR to 0.13 ± 0.14 logMAR, respectively (P<.001).The mean spherical equivalent improved from −6.93 ± 3.52 diopters (D) preoperatively to −3.23 ± 2.81 D at 6 months and the mean refractive cylinder, from −4.65 ± 1.85 D to −3.90 ± 1.70 D, respectively. The mean keratometry decreased from 49.84 ± 3.58 D preoperatively to 47.90 ± 3.58 D postoperatively (P<.001). Three eyes had ring exposure, and 1 eye had bacterial keratitis and ring exposure. CONCLUSION: Intacs implantation appeared to be effective in improving UCVA and BSCVA in patients with mild to moderate keratoconus and contact-lens intolerance.