Intaoperative correction of induced astigmatism in Conductive Keratoplasty (CK) for Hyperopia.

Abstract

Abstract: : Purpose: To report on the treatment of surgically induced astigmatism intra–operatively during Conductive Keratoplasty (CK) application for correcting hyperopia. Methods: CK utilizes radiofrequency energy applied to the peripheral corneal stroma to shrink the collagen and so alter the central cornea to correct hyperopia. Twenty–four consecutive patients (33 eyes) who underwent CK for hyperopia and were treated intra–operatively for induced astigmatism were evaluated. Utilizing automated keratometric readings taken during the procedure, we applied additional spots at the minus cylinder or the flat axis at the 7 mm zone until the intra–operative astigmatism was 2 D or less. Results: The intra–operative treatment reduced the astigmatism by an average of 1.54 ± 1.45 D. The mean induced astigmatism was 2.88 ± 1.29 D for eyes that received 8 spots, 3.19 ±1.48 D for eyes that received 16 spots, 2.9 ± 1.03 D for eyes that received 24 spots and 4.03±1.12D for eyes that received 32 spots. Additional spots reduced astigmatism in most of the cases to less than 2 D. Conclusions: Intra–operative treatment of astigmatism through the addition of more spots at the minus cylinder or flat axis reduced the degree of induced astigmatism. Surgically induced astigmatism was observed more frequently in patients who received 32 treatment spots and 6 mm treatment zone application

Keywords: hyperopia • refractive surgery • refractive surgery: complications