Analysis of an Approach to Astigmatism Correction during Cataract Surgery

Abstract

Purpose: To determine if a system of astigmatic keratomy at the time of cataract surgery is safe and effective. Setting: Academic Ophthalmology Center. Methods: One hundred and ten consecutive patients with greater than 0.50 diopters (d) of cylinder with the rule (WTR) and 0.75 d against the rule (ATR) were enrolled. Those with an axis between 16 and 74° and 106 and 164° were defined as oblique axis. Peripheral clear corneal relaxing incisions 600 µm deep were used with a nomogram of 60° length per 1.0 d of attempted correction. Keratometry was taken from IOL Master biometry and refractive results at 4–12 weeks were compared. Results: 60.5% of ATR, 62% of WTR and 23% of oblique attempted correction was achieved. Splitting the patients to under and over 70 years of age had no impact on the results. Of the 14 overcorrected, 7 had oblique cylinder (p = 0.009) and 10 had less than 1 d of preoperative cylinder (p = 0.00015). Conclusions: Using the IOL Master topography with this nomogram was quite effective in reducing preoperative cylinder. Oblique axis results were unpredictable, however, and much more likely to lead to an overcorrection.