Corneal astigmatism after cataract surgery with 4.1 mm BENT scleral and 4.1 mm plus meridian corneal incisions

PURPOSE: To determine whether the 4.1 mm BENT (between 9 and 12 o'clock) scleral incision or the 4.1 mm plus meridian corneal incision (PMCI) is better at minimizing postoperative astigmatism. SETTING: Department of Ophthalmology, Kobe City General Hospital, Kobe, Japan. METHODS: This prospective study comprised 58 eyes of 29 consecutive patients with bilateral cataract. One eye was randomly assigned to have cataract surgery with a 4.1 mm BENT scleral incision and the other eye, with a 4.1 mm PMCI. Corneal astigmatism was measured before surgery and 1, 3, 10, 30, and 100 days after surgery. RESULTS: Mean astigmatism preoperatively and on postoperative days 1, 3, 10, 30, and 100 in the BENT scleral incision group was 0.99 +/- 0.66, 1.53 +/- 1.11, 1.12 +/- 0.72, 1.26 +/- 0.81, 1.16 +/- 0.73, and 1.09 +/- 0.64 diopters (D), respectively. Means in the PMCI group were 1.14 +/- 0.79, 1.38 +/- 0.98, 1.17 +/- 0.88, 1.31 +/- 0.77, 1.01 +/- 0.70, and 1.00 +/- 0.60 D. respectively. Astigmatism on days 1 and 10 postoperatively was significantly greater than preoperatively in the BENT group (P < .03) but not in the PMCI group. The changes in astigmatism were less in the PMCI group at every examination and were significantly different 30 days postoperatively (P < .05). The negative correlation between preoperative astigmatism and the final postoperative change was significant in both groups (P < .032); the value of x-intercept of the regression line was 1.37 D in the BENT scleral incision group and 0.82 D in the PMCI group. CONCLUSION: In cataract surgery using a 4.1 mm incision, the PMCI surpassed the BENT scleral incision in minimizing postoperative corneal astigmatism.