Tomographic Analysis of Incision Sequence on Anterior and Posterior Surgically Induced Astigmatism in Cataract Surgery

Abstract Purpose: To evaluate of effect incision sequence on anterior and posterior astigmatism and SIA at cataract surgery using Scheimpflug tomography measurements.Methods: We evaluated 86 patients who had gone cataract surgery between October 2018 to March 2019. All eyes were measured with a Scheimpflug tomography system preoperatively and at 1 month after surgery which included anterior and posterior corneal surfaces. The surgery was begin with side incision in group 1 differently the main incision was done first in group 2. Student t test and Pearson’s correlation were performed. P values < 0.05 were considered statistically significant.Result: Surgically induced anterior astigmatism (SIA-A) 0.76±0.43, 0.67±0.38 and surgically induced posterior astigmatism(SIA-P) 0.27±0.19 0.23±0.19 respectively in group 1 and group 2. 1D or greater SIA-A was found 24.4 % and 15.6% and 0.5 D or greater SIA-P was found 14.6% and 12.2% respectively in group 1 and group 2. There was a significant increase in anterior astigmatism (p=0.002, 0.005 respectively in group 1 and 2), but not in the posterior astigmatism (p=0.471 and 0.247 respectively in group 1 and 2). In the subgroup analysis, group 2 has lower SIA-A then group 1 except oblique subgroup and group 2 has lower SIA-P for all subgroups but it wasn't statistically significant.Conclusion: Making the main incision first caused less SIA on both anterior and posterior surfaces however this difference was not significant.