One year follow-up of astigmatism after 4.0 mm temporal clear corneal and superior scleral incisions.

PURPOSE

To compare the effect of 2 contemporary sutureless cataract surgery incisions on corneal astigmatism 1 year after surgery.

SETTING

Outpatient Clinic, Department of Ophthalmology, Vejle Hospital, Denmark.

METHODS

Sixty-nine patients who had cataract surgery in 1997 with a 4.0 mm temporal clear corneal (n = 32) or superior scleral (n = 37) incision were examined 1 year postoperatively. Surgically induced astigmatism was analyzed by vector analysis, vector decomposition, and polar values using preoperative and postoperative keratometric readings.

RESULTS

Vector analysis revealed a slightly lower median induced cylinder in the clear corneal patients; 0.41 diopter (D) (95% confidence limits [CL] 0.24 to 0.67 D) versus 0.61 D (95% CL 0.49 to 0.73 D) (P < .05). Decomposition of the induced cylinder (against the rule/total) showed statistically significant differences in the direction of the cylinder; 0.21 (95% CL 0.03 to 0.41) versus 0.90 (95% CL 0.82 to 0.95) (P < .00001). The directional difference was confirmed by polar values.

CONCLUSION

Both incisions induced low and comparable amounts of astigmatism. The directional differences were modest. Findings in previous studies of a poor outcome after clear corneal incisions were not confirmed in this long-term follow-up.