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

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.