# Comparison of 2.2 mm vs. 2.6 mm corneal incisions in phacoemulsification in hard nuclear cataracts: impact on intraoperative energy and postoperative corneal recovery

## TL;DR

This study compared 2.2 mm and 2.6 mm corneal incisions in cataract surgery, finding no difference in energy use or long-term recovery, but smaller incisions caused more short-term swelling.

## Contribution

The study provides new evidence on the impact of incision size on corneal recovery and intraoperative energy use in hard nuclear cataract surgery.

## Key findings

- No significant difference in intraoperative ultrasound energy use between 2.2 mm and 2.6 mm incisions.
- Smaller 2.2 mm incisions caused more short-term edema at the incision site compared to 2.6 mm incisions.
- Both incision sizes resulted in similar corneal endothelial cell loss and visual acuity outcomes.

## Abstract

This study sought to evaluate the differential impacts of two corneal incision sizes, 2.2 mm and 2.6 mm, on the utilization of intraoperative ultrasound energy and the subsequent postoperative corneal recovery in patients presenting with hard nuclear cataracts.

A retrospective cohort study was undertaken, encompassing cataract patients classified with nuclear hardness grades III to V according to the Emery-Little classification. Participants were allocated into two groups based on the incision size: 2.2 mm and 2.6 mm. Key metrics, including endothelial cell density (ECD), central corneal thickness (CCT), incisional corneal thickness (ICT), and best-corrected visual acuity (BCVA), were assessed preoperatively and at intervals of 1 day, 1 week, 1 month, and 3 months postoperatively. Additionally, intraoperative phacoemulsification parameters and any complications were documented.

The study encompassed a total of 100 eyes, with 50 eyes in each group. No statistically significant differences were detected in cumulative dissipated energy (CDE) or ultrasound time (UST) between the two groups (P > 0.05). Both groups exhibited a significant postoperative decline in ECD (P < 0.05), yet no significant intergroup difference was observed in the magnitude of this reduction (P > 0.05). Central corneal thickness (CCT) and intraocular pressure (ICT) exhibited a statistically significant increase at both 1 day and 1 week postoperatively when compared to baseline measurements (P < 0.05). Notably, the increase in ICT was significantly more pronounced in the 2.2 mm incision group at both time points (P < 0.05). Best-corrected visual acuity (BCVA) showed significant improvement in both groups following surgery (P < 0.05), with no significant intergroup differences observed at any follow-up interval (P > 0.05). Additionally, no significant difference in central corneal edema was detected between the two groups (P > 0.05).

The corneal incision size (2.2 mm versus 2.6 mm) did not influence the use of intraoperative ultrasound energy or result in differential corneal endothelial cell loss. However, smaller incisions (2.2 mm) were associated with increased short-term edema at the incision site, potentially impacting early wound healing.