Investigation of surgically induced astigmatism resulting from femtosecond laser-assisted cataract surgery using a 2.2 mm clear corneal incision

Abstract

Objective To evaluate surgically induced astigmatism (SIA) resulting from femtosecond laser-assisted phacoemulsification cataract surgery with a 2.2 mm clear corneal incision. Methods A prospective, comparative analysis was performed in a case series. A total of 105 eyes of 84 patients (from No. 1 cataract department of Shanxi Eye Hospital) who underwent femtosecond laser-assisted phacoemulsification cataract surgery between March 2014 and April 2016 were enrolled in this study. The main outcomes were a comparison of SIA, far visual acuity, and spherical refractive power preoperatively and 1, 3, and 6 months postoperatively. Distance visual acuity was recorded as logMAR. Based on follow-up times (1, 3, and 6 months postoperatively), lens nucleus hardness (grades Ⅱ, Ⅲ, Ⅳ), corneal astigmatism types (with-the-rule, against-the-rule, oblique) and laterality (left, right), SIA was analyzed using Alphins vector analysis. Data were analyzed using repeated measured ANOVA. Results The mean preoperative logMAR visual acuity was 0.65 ± 0.24, which was significantly different from postoperative logMAR visual acuity at 1 month (0.07±0.02), 3 months (0.06±0.01), and 6 months (0.06±0.01). No significant logMAR visual acuity differences were found at the three postoperative follow-up times. SIAs at 1, 3, and 6 months after surgery were 0.28 ± 0.11 D, 0.25 ± 0.13 D, 0.24 ± 0.10 D, respectively. No statistically significant differences in SIA were found when postoperative follow-up times (1, 3, and 6 months) and factor groups for lens nucleus hardness (grades II, Ⅲ, Ⅳ), corneal astigmatism types (with-the-rule, against-the-rule, oblique) and laterality (left, right) were compared. Conclusion Femtosecond laser-assisted phacoemulsification cataract surgery using a 2.2 mm clear corneal incision can provide stable SIA and better postoperative visual acuity. Key words: Cataract; Phacoemulsification; Femtosecond laser; Surgical induced astigmatism