The influence of corneal incision size on endothelial cell loss and surgically induced astigmatism following phacoemulsification cataract surgery

OBJECTIVE Corneal incision size has influence both on corneal biomechanics and intracameral fluid dynamics during phacoemulsification cataract surgery. The aim of this study was to evaluate the impact of corneal incision size on endothelial cell loss and surgically induced astigmatism (SIA) following phacoemulsification cataract surgery. METHODS This prospective, randomized, and comparative study included 61 eyes with senile cataracts. The patients were randomly assigned to 2.2 mm and 2.8 mm corneal incision sizes and were operated with the same phacoemulsification system. Phacoemulsifcation energy parameters, pre-operative and post-operative endothelial cell counts and corneal astigmatism values were specifically recorded. SIA was calculated according to Alpins method and the results of both groups were compared. RESULTS There were 31 eyes in the microincisional (2.2 mm) group and 30 eyes in the standard incision (2.8 mm) group. There was no significant difference between the groups for age and gender distribution (p=0.09 and p=0.18, respectively). Similar levels of cumulative dissipated energy was used during phacoemulsification in both groups (p=0.70). SIA was slightly higher in the standard incision group compared to microincisional group (0.47D at 64° vs. 0.37D at 61°, p=0.30). Pre-operative and post-operative uncorrected visual acuity (UCVA) was similar between the groups (p=0.45 and p=0.27).Endothelial cell loss tended to be slightly higher in the microincisional group compared to standard incision group (174.87±132.27 vs. 160.84±121.58, p=0.75), but this difference was not statistically significant. CONCLUSION Smaller corneal incisions slightly reduced SIA, but tended to induce more endothelial cell loss. This small difference in SIA did not cause a significant change in the postoperative UCVA. Therefore, the trend in reducing corneal incision sizes below 2.8 mm might not be contributing the surgical outcomes of the patients, especially when we consider potential corneal endothelial changes.