Dynamic changes of 2.8 mm clear corneal incisions architecture with different angles and comparison of safety

Background

In recent years, the relationship between transparent corneal incision and endophthalmitis is attracting more and more attention.Transparent corneal incision configuration become a research hotspot.

Objective

This study was to analyze dynamic architectural changes of 2.8 mm clear corneal incisions with different angles using anterior segment optical coherence tomography (AS-OCT) and safety.

Methods

A retrospective cases-control study was performed.Seventy-three eyes of 63 patients who received phacoemulsification combined with implantation of intraocular lens (IOL) were included in Ordos Central Hospital from January to October 2015.The patients were divided into incision≤45°group and incision>45°group according to the angle of incision revealed by OCT.Thirty-eight eyes of 32 patients was in incision≤45° group and 35 eyes of 31 patients was in incision > 45° group.Corneal incision quality was analyzed preoperative 1 day and postoperative 1 day, 1 week and 1 month by AS-OCT.The corneal thickness at the incision, the length of the healed incision, the opening of the outer incision and inner incision and the detachment of the posterior elastic layer were observed.Written informed concent was obtained from each patient before surgery.

Results

The mean angle of the incisions in the incision≤45° group was 31.6°±5.4°, and that in the incision>45° group was 54.3°±5.5°.The corneal thickness in the incision≤45° group was significantly thicker than that in the incision>45° group at postoperative 1 day and 1 week (t=5.96, P=0.00; t=4.69, P=0.00). The ratio of incision length without coaptation was higher in the incision≤45° group than that in the incision>45° group at postoperative 1 day, 1 week and 1 month, respectively (Z=-5.14, P=0.00; Z=-5.46, P=0.00; Z=-3.52, P=0.00). The incidence of endothelial gaping was significantly lower in the incision≤45° group than that in the incision>45° group at 1 day, 1 week and 1 month after surgery (χ²=6.88, P=0.01; χ²=14.87, P=0.00; χ²=9.07, P=0.00). The closure rates of outside incision were 100% in both two groups.There were no statistically significant differences in Descemet detachment at 1 day, 1 week and 1 month after surgery between two groups(χ²=0.15, P=0.70; χ²=1.29, P=0.36; χ²=0.02, P=0.89). Lip recession and contracture were observed in 3 eyes in the incision group.

Conclusions

At the early stage after phacoemulsification, when the intraocular pressure is changing constantly, small angle clear corneal incision appears to be a good closure and therefore is safer.

Tomography, optical coherence; Anterior segment; Cataract; Cornea; Incision; Architecture