Analysis of an approach to astigmatism correction during cataract surgery

To determine if a system of astigmatic keratomy at the time of cataract surgery is safe and effective.

Academic Ophthalmology Center.

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 degrees and 106 and 164 degrees were defined as oblique axis. Peripheral clear corneal relaxing incisions 600 mum deep were used with a nomogram of 60 degrees length per 1.0 d of attempted correction. Keratometry was taken from IOL Master biometry and refractive results at 4-12 weeks were compared.

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).

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.