Low, Medium And High Astigmatism: Refractive Outcomes Analysis In Patient With Different Preop Astigmatism

The aim of this study was to analyze the refractive outcomes in patients with different degrees of astigmatism undergoing cataract surgery with toric monofocal intraocular lens (IOL) implantation and  to evaluate whether the correction of lower astigmatism was as effective as the correction of higher astigmatism.

For the purpose of the study the astigmatic defect (corneal and refractive)was considered as absolute value (without considering the sign).The patients were divided in 3groups basing on the value of preoperative total corneal astigmatism (real keratometry)measured using Anterior Segment OCT (Tomey,CASIA 2 device).Group 1:eyes with total corneal astigmatism ≤ 1 D, group 2:eyes with total corneal astigmatism between 1D and 1.5D and group 3: eyes with total corneal astigmatism >1.5D.A comparison between the preoperative total corneal astigmatism and the post operative refractive astigmatism among the groups was performed one month after the surgery. In addition,the percentage of residual astigmatism 1 month after the surgery was analysed too.

138 eye were enrolled for this study. Group 1 included 55 eyes , group 2 included 46 eyes and group 3 included 37 eyes. The average residual refractive astigmatism was 0.25D, 0.16 D, and 0.43 D in the group 1, 2 and 3 respectively(p=0.002). Specifically, the difference was statistically significant between the group 1 and 3 (p=0.017, adj p=0.034) and between the group 2 and 3 (p=0.00025, adj p= 0.00049). The percentage of residual refractive astigmatism was 37% in group 1, 12% in group 2, and 19% in group 3 (p=0.015), with particular significance between group 1 and 2 (p=0.0023, adj p=0.0046).