Astigmatic keratotomy effect of single-hinge, clear corneal incisions using various preincision lengths

To investigate the astigmatic keratotomy effect of a modified single-hinge cataract incision.

Department of Ophthalmology, San Juan de Dios Hospital, Tenerife, Spain.

This prospective study evaluated the astigmatic changes resulting from preincision grooves of less than 40, 45, and 55 degrees in arc length used with a single-hinge, self-sealing cataract incision in 144 eyes that had against-the-rule corneal astigmatism preoperatively. The intended 90% depth preincision was centered on the steep meridian and lengthened according to the amount of preoperative astigmatism. Outcome measurements were obtained by calculating the surgically induced astigmatism vectors and the postoperative keratometry changes 1 day, 1 week, and 1, 3, and 6 months after surgery.

Three months postoperatively, astigmatism decreased by 0.03, 0.30, and 0.68 diopter in the less than 40, 45, and 55 degree incision length groups, respectively. The differences between the 45 and 55 degree groups and the less than 40 degree group was statistically significant (P < .05). Similar results were observed 6 months after surgery.

The astigmatic preincision modification produced statistically significant increasing reductions in preoperative astigmatism according to preincision length.