Circular keratotomy to reduce astigmatism and improve vision in stage I and II keratoconus.

PURPOSE: To report the use of circular keratotomy in eyes with stage I and II keratoconus to reduce astigmatism.

METHODS: A retrospective analysis was performed of all eyes operated from 1993 to 2006 by one surgeon using circular keratotomy for stage I and II keratoconus. Results were evaluated for reduction of corneal astigmatism, refractive stability, and change in best spectacle-corrected visual acuity (BSCVA).

RESULTS: Forty-six eyes in 36 patients were evaluated. Corneal (keratometric) astigmatism and refractive astigmatism were significantly reduced, particularly in eyes with preoperative astigmatism > or = 2.00 diopters (D). Preoperative astigmatism correlated with reduction of astigmatism (R = 0.81). Astigmatism stabilized after 1 year in 64% of 28 eyes that were seen both within the first year after surgery and then at some time point > or = 2 years after surgery. In this group, astigmatism changed < or = 2.00 D in 94% of eyes between 1-year follow-up and the last examination. Mean BSCVA improved from 20/44 to 20/33 (P < .01), with 20 (43%) of 46 eyes gaining 2 lines or more, 22 (48%) of 46 eyes changing by less than 2 lines, and 4 (9%) of 46 eyes having a worse BSCVA at the last examination compared with preoperatively.

CONCLUSIONS: Circular keratotomy provides significant reduction in astigmatism, improved BSCVA, and stabilization of astigmatic changes in most eyes, although some eyes show limited benefit. Eyes with higher preoperative astigmatism appear to be more likely to benefit from the procedure than those with lower preoperative astigmatism. Circular keratotomy also resulted in reasonable clinical results for the treatment of stage I and II keratoconus.