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.