Radial keratotomy enhancements for residual myopia

A systematic method of performing radial keratotomy enhancements in undercorrected eyes may increase accuracy and predictability and decrease the number of procedures required. A consecutive series of 372 radial keratotomy procedures, including 110 eyes that received enhancements under a systematic protocol, was evaluated.

Radial keratotomy was performed using the Reliable Keratotomy software, which uses the Thornton nomogram for primary radial keratotomy and provides a systematic method of performing enhancements.

Ninety eyes (24%) received one enhancement, 16 eyes (4%) received two enhancements, and four eyes (1%) received three enhancements. Mean final spherical equivalent refraction was -0.44 D (-4.00 to +1.875 D, SD 0.86) for eyes that did not receive enhancements and -0.44 D (-2.50 to +1.00 D, SD 0.61) for eyes that had enhancements. Mean final residual myopia for the entire cohort was -0.44 D (-4.00 to +1.875 D, SD 0.79). At final examination, 242 (65%) eyes had a refraction within +/- 0.5 D and 298 (80%) within +/- 1.00. Among eyes that received enhancements, 75 (68%) had a refraction within +/- 0.50 D, and 89 (81%) within +/- 1.00 D; 40 eyes (36%) had uncorrected visual acuity of 20/20 or better, 99 eyes (90%) 20/40 or better, and all but one eye (99%) 20/80 or better at the final postoperative examination. Among the entire cohort, 130 eyes (35%) had uncorrected visual acuity of 20/20 or better, 312 (84%) had 20/40 or better, and 350 (94%) had 20/80 or better. No eye lost more than one line of spectacle-corrected visual acuity.

A systematic approach to enhancement of undercorrected eyes after radial keratotomy, combined with accurate surgery, may reduce the need for multiple enhancements as well as the overcorrection rate, and provide improved uncorrected visual acuity.