Clear Corneal Incision Architecture Imaging after Torsional Phacoemulsification of Hard Nuclear Cataract through a 2.2 mm and a 3.0 mm Large Tunnel

Purpose: To compare the morphological characteristics and the wound edema degree of clear-cornea microincisions and small-incisions for hard cataract removal.Setting: The Eye Hospital of Wenzhou Medical College.Design: Prospective randomized study. Methods: Fifty eyes from 36 consecutive patients with hard cataract were included. They were randomized to have phacoemulsification through a clear-cornea microincision (2.2 mm, n=25) or small-incision (3.0 mm, n=25). Anterior segment optical coherence tomography evaluation was performed preoperatively and postoperatively, including wound architecture and incisional corneal thickness (ICT).Results: Endothelial gaping was more common in the 2.2 mm group than in the 3.0 mm group at 2 hours (48 vs 12%) and 1 week (28 vs 12%) postoperatively, although the statistical difference was significant only at 2 hours. There was no statistically significant difference between the two groups in the incidence of epithelial gaping, local detachment of Descemet’s membrane, loss of coaptation, and posterior wound retraction. At 2 hours and 1 week after surgery, the mean ICTd was slightly higher in 3.0 mm group (52.1±12.5% and 46.4±12.3%, respectively) than in 2.2 mm group(51.4±11.6% and 40.6±15.1%, respectively), with no statistically significant differences. On the contrary, the ICTd was statistically higher in 3.0 mm group than 2.2 mm group at 1 month (16.8±10.0% vs 10.2±5.8%, P = 0.007) and 3 months (12.1±8.1% vs 6.0±4.5%, P = 0.002).Conclusion: In hard cataract phacoemulsification, microincisions increase the risk of endothelial gaping in the early postoperative period, compared to small incisions. However, they induce a lower amount of corneal edema.