Nonfreeze myopic keratomileusis for myopia in 158 eyes.

Abstract

Background: A prospective evaluation of non-freeze myopic keratomileusis is reported.

Methods: One hundred and fifty-eight eyes of 98 consecutive patients underwent nonfreeze myopic keratomileusis, with BKS 1000 (Eyetech-M.V.A.A.G, Balzers, Liechtenstein) refractive set. The preoperative myopia ranged from -6.25 to -28.00 D. Mean follow up was 591.3 days (range, 90 to 1500 days).

Results: The logarithmic mean preoperative spectacle-corrected visual acuity was 0.48 +/- 0.31 (20/40), and 0.44 (20/50) +/- 0.30 after 2 years and longer, whereas mean uncorrected visual acuity was 0.32 +/- 0.28 (20/70) in 34 of 82 (41.5%) eyes. After 2 years and longer, 21 of 82 (25.6%) eyes were within 1.00 D of emmetropia, and 43 of 82 (52.4%) were within 2.00 D. The subjective spherical equivalent refraction confidence interval at 90% was 9.28 D (-6.85 to +2.43 D). No refractive instability was detected during follow-up. We detected a trend toward improvement of spectacle-corrected visual acuity with time. However, after 2 years and longer, there was an increase in astigmatism of more than 1.00 D, when compared to the preoperative values, and 14 of 82 (17%) eyes lost two or more lines of spectacle-corrected visual acuity (statistically significant: p < .01).

Conclusion: The nonfreeze myopic keratomileusis procedure, with BKS 1000, substantially reduces moderate to high myopia, but predictability of refractive outcome is only fair, and the frequency of optical complications including irregular astigmatism is higher than desired.