To evaluate the effectiveness of femtosecond laser penetrating corneal relaxing incisions (CRIs) in reducing corneal astigmatism during cataract surgery.
Shanxi Eye Hospital, Taiyuan, Shanxi Province, China.
Prospective case series.
Using the Lensx laser, CRIs were placed at a diameter of 8.0 mm with a depth of 90%. Corneal astigmatism was measured before surgery and 1 and 3 months after surgery. Vector analyses were performed. To obtain the net corneal changes, the with-the-wound (WTR) and against-the-wound (ATR) changes were calculated along the meridian of the CRI. Multiple regression analysis with generalized estimating equations was used to evaluate the factors contributing to the effectiveness of CRIs.
The study comprised 51 eyes. One and 3 months postoperatively, respectively, the mean keratometric astigmatism was reduced significantly by 0.65 diopter (D) and 0.67 D (both P
< .05); compared with preoperative corneal astigmatism, the percentage of eyes within ±0.50 D of refractive astigmatism significantly increased by 42.6% and 46.7% (both P
< .05) and the mean refractive astigmatism was significantly decreased at 1 month (0.27 @ 93 versus 0.17 × 17) (P
< .05) but not at 3 months (0.09 @ 138 versus 0.07 × 172) (P
> .05). The mean WTW and ATW changes were −1.05 D and −1.00 D, respectively, and 14.9% and 6.7% of eyes, respectively, were overcorrected. Age, CRI length, and CRI location were factors contributing to net corneal changes. A nomogram is proposed.
Femtosecond laser CRIs were effective in reducing corneal astigmatism during cataract surgery, and their long-term effectiveness should be evaluated.
Dr. Koch is a consultant to Abbott Medical Optics, Inc., Alcon Laboratories, Inc., and Revision Optics, Inc. None of the other authors has a financial or proprietary interest in any material or method mentioned.