Paired Opposite 4 mm Clear Corneal Incisions on Steep Meridian during Phacoemulsification

To evaluate the effect of opposite clear corneal incisions (OCCI) with 4 mm incisions on the steep meridian on postoperative astigmatism.

This study was performed on 64 eyes of 55 patients with keratometric astigmatism of ≥ 1 diopter (D) undergoing phacoemulsification. Patients were divided into two groups, with‑the‑rule (WTR) astigmatism and against‑the‑rule (ATR) astigmatism. Initial incisions in the WTR group were performed on the temporal side with 3.2 mm keratome and paired stab incisions were performed on the steep meridian. At the end of the surgery, stab incisions were enlarged to 4 mm. Follow‑up visits were scheduled at 1, 3, 6, and 12 months postoperatively, which included refraction and keratometry.

It was found that the mean preoperative keratometric astigmatism was 2.06 ± 0.86 D. The postoperative mean keratometric astigmatism was 1.3 ± 0.7 D after 1 month and 1.2 ± 0.7 D after 12 months. The mean astigmatism correction between the preoperative measure and that taken at 1 month was statistically significant (P = 0.001), but there was no significant change in the severity of astigmatism afterward. The mean surgically‑induced astigmatism was found to be 1.99 ± 0.9 D. The 12‑month changes of mean absolute astigmatism were: 1.06 ± 0.7 D in the WTR group, and 0.53 ± 0.7 D in the ATR group. The difference between the two groups was statistically significant (P = 0.02).

Based on our findings, we posit that paired OCCI on the steep axis, using 4 mm incisions is an effective technique to correct preoperative astigmatism.