Comparison of astigmatism correction between anterior penetrating and intrastromal arcuate incisions in eyes undergoing femtosecond laser-assisted cataract surgery.

PURPOSE

To compare the safety, efficacy, and predictability of femtosecond laser-enabled anterior penetrating and intrastromal arcuate incisions for the correction of preoperative astigmatism at the time of cataract surgery.

SETTING

Nethradhama Super Speciality Eye Hospital, Bangalore, India.

DESIGN

Prospective randomized comparison study.

METHODS

This study included 50 eyes of 50 patients who had femtosecond laser-assisted cataract surgery with the CATALYS Precision System (Johnson & Johnson Vision Care, Inc.). Twenty-five eyes received anterior penetrating and 25 eyes received intrastromal arcuate incisions for the correction of corneal astigmatism in the range of 0.75 to 2.00 diopters (D). Six months postoperatively, vector analysis of astigmatism was performed using the Alpins method with the ASSORT software.

RESULTS

The mean preoperative keratometric astigmatism and target-induced astigmatism were 1.07 D and 1.16 D in the anterior penetrating group and 1.23 D and 1.50 D in the intrastromal group, respectively. There was no statistically significant difference between the postoperative keratometric astigmatism (anterior penetrating = 0.65, intrastromal = 0.90, P value = .13) and surgically induced astigmatism (anterior penetrating = 1.23, intrastromal = 1.08, P value = .55) at 6 months postoperatively. The correction index was 0.95 in the anterior penetrating group and 0.55 in the intrastromal group, signifying an undercorrection of 5% and 45% of eyes in the anterior penetrating and intrastromal group, respectively. Eighty percent of eyes in the anterior penetrating group and 72% of eyes in the intrastromal group were within ±0.5 D of refractive astigmatism.

CONCLUSIONS

Both anterior penetrating and intrastromal incisions were effective in reducing preoperative astigmatism using the femtosecond laser technology. However, the anterior penetrating incisions showed comparatively better correction, whereas the intrastromal incisions resulted in significant undercorrection at 6 months.