INTRASTROMAL CORNEAL RING - 12-MONTH SIGHTED MYOPIC EYES

BACKGROUND: To evaluate the efficacy, predictability, and stability of the refractive effect produced by the Intrastromal Corneal Ring (ICR( R)), the authors completed a 12-month study on 10 myopic eyes. METHODS : Ten patients with preoperative refractive errors ranging from -2.63 diopters (D) to -4.25 D (mean, -3.30 D) participated in the study. The attempted correction was -2.50 D for a 7.0-mm diameter, 0.3-mm thick ICR. One eye of each patient received an ICR. RESULTS: The average cha nge in spherical equivalent at 12 months was -2.25 D (SD 0.54 D; range , -1.62 to -3.25 D). All patients maintained a spectacle-corrected vis ual acuity of 20/20 or better during the 12-month study period, with t he exception of patient no. 6 who saw 20/30 at the B-month examination . Her spectacle-corrected visual acuity returned to 20/20 a few days a fter the ICR was explanted and remained stable throughout the study. U ncorrected visual acuity had improved to 20/40 or better in all patien ts on postoperative day 1 and remained in this range for the 9 eyes (9 0%) during the 12 months of follow up. At postoperative month 12, 9 of 9 eyes (100%) had an uncorrected visual acuity of 20/40 or better wit h 3 of 9 eyes (33%) seeing 20/20 or better. The remaining patient, no. 6, experienced a tear in Descemet's membrane during the procedure and required explantation of the ring after 6 months due to induced astig matism and deterioration of uncorrected visual acuity. Two patients de veloped infiltrates that resolved with the use of antibiotics. The mos t common postoperative ocular findings were peripheral corneal haze in all eyes that diminished over time, minute lamellar channel deposits (7 of 10 eyes, 70%), deep stromal neovascularization (5 of 10 eyes, 50 %), and pannus (5 of 10 eyes, 50%). CONCLUSION: This preliminary study shows that implantation of an intrastromal corneal ring of this dimen sion (0.3-mm thick) can reduce approximately 1.50 to 3.00 D of myopia and maintain spectacle-corrected visual acuity.