Effect of femtosecond laser-assisted steepest-meridian clear corneal incisions on preexisting corneal regular astigmatism at the time of cataract surgery

摘要

AIM:To investigate the clinical efficacy and safety of femtosecond laser-assisted steepest-meridian clear corneal incisions for correcting preexisting corneal astigmatism performed at the time of cataract surgery.METHODS:This prospective case series study comprised consecutive age-related cataract patients with corneal regular astigmatism(range:+0.75 to+2.50 D)who had femtosecond laser-assisted steepest-meridian clear corneal incisions(single or paired).Corneal astigmatism was performed with the Pentacam preoperatively and 3 mo postoperatively.Total corneal astigmatism and steepestmeridian measured in the 3-mm central zone were used to guide the location,size and number of clear corneal incision.The vector analysis of astigmatic change was performed using the Alpins method.RESULTS:Totally 138 eyes of 138 patients were included.The mean preoperative corneal astigmatism was 1.31±0.41 D,and was significantly reduced to 0.69±0.34 D(equivalent to difference vector)after surgery(P<0.01).The surgically-induced astigmatism was 1.02±0.54 D.The correction index(ratio of target induced astigmatism and surgically-induced astigmatism:0.72±0.36)as well as the magnitude of error(difference between surgically-induced astigmatism and target induced astigmatism:-0.29±0.51)represented a slight under correction.For angle of error,the arithmetic mean was 1.11±13.70,indicating no significant systematic alignment errors.CONCLUSION:Femtosecond-assisted steepest-meridian clear corneal incision is a fast,customizable,adjustable,precise,and safe technique for the reduction of low to moderate corneal astigmatism during cataract surgery.