Anterior segment optical coherence tomography evaluation of the integrity of clear corneal incisions: a comparison between 2.2-mm and 2.65-mm main incisions

Abstract

Purpose: To compare wound characteristics and integrity of the 2.2-mm and 2.65-mm clear corneal incisions.

Design: Prospective, randomized clinical trial.

Methods: Patients undergoing phacoemulsification with lens implant were randomized to receive a 2.2-mm or 2.65-mm temporal clear corneal incision. The incisions were evaluated at 2, 24, and 96 hours for gape and wound architecture using anterior segment optical coherence tomography and for integrity using the Seidel test. Squareness of an incision was calculated (ratio of the incision length to the width).

Results: There were 30 patients in each group. Both incision sizes were watertight, although a mild internal main wound gape was detected on anterior segment optical coherence tomography in 35 eyes (58.3%) at 2 hours. The smaller wound was more square (0.81; standard deviation [SD], 0.11) than the larger wound (0.62; SD, 0.08; P < .001, t test). The mean squareness of eyes without wound gape at 2 hours (0.66; SD, 0.11) was lower than those with a wound gape (0.75; SD, 0.14; P = .008). A squareness factor of 0.72 or more had a positive predictive value for presence of wound gape at 2 hours of 79.3% and a negative predictive value of 61.3%. One side port incision with squareness of 1.39 had a mild leak at 2 and 24 hours, but no gape was seen on anterior segment optical coherence tomography.

Conclusions: Both the 2.2-mm and 2.65-mm clear corneal incisions clinically were competent, but the side port incision may leak. A truly square wound has a greater likelihood of being associated with internal wound gape at 2 hours after surgery, especially if the squareness factor is 0.72 or more.