Topography-guided femto-lasik in virgin eyes: Treating manifest versus measured astigmatism

Abstract

Purpose: To assess the stability, safety, predictability, and efficacy of topography-guided myopic Femto-LASIK with two different treatment protocols. Setting: Ebsar Eye center, Benha, Qalyopia, Egypt. Design: Single-center, retrospective, COHORT control study. Methods: A total of 330 eyes enrolled in the study in group A and 322 eyes enrolled in group B underwent uncomplicated primary bilateral topography-guided Femto-LASIK. Group A was treated with the subjective clinical refraction; however, group B was treated with the modified refraction according to ALCON protocol. Results: The mean preoperative refractive spherical equivalent (MRSE) was −4.85±1.90D and −5.0±1.93D in group A and B, respectively (P = 0.86), and a cylinder of −0.95±0.80 D and −0.92±0.81D, respectively. At the 12 months’ postoperatively, the residual manifest SE within ± 0.5D was achieved by 82.86% of eyes in group A compared to 83.93% in group B. Of eyes, 92.06% had ≤0.5 astigmatism dioptre, while 100% of eyes had ≤1.0 astigmatism dioptre in group A (315 eyes); however, 91.80% of eyes had ≤0.5 astigmatism dioptre, while 100% of eyes had ≤1.0 astigmatism dioptre in group B. Conclusion: Topographic modification of the magnitude and axis of astigmatism treated using ALCON protocol when different from the clinical refraction may offer good refractive outcomes when we apply the Alcon precalculation considerations.