Analysis of corneal astigmatism in cataract surgery candidates at a teaching hospital in Shanghai, China

Abstract

Purpose: To describe and quantify the pattern of corneal astigmatism in cataract surgery candidates and to provide information for cataract surgeons and intraocular lens (IOL) manufacturers.

Setting: Zhongshan Hospital, Fudan University, Shanghai, China.

Design: Cross-sectional study.

Methods: The datasets of cataract surgery candidates acquired between November 1, 2009, and November 30, 2011, were collected and analyzed. Keratometry values were optically measured by partial coherence interferometry (IOLMaster) before cataract extraction. Spearman rank correlation coefficients were used to estimate bivariate correlations. The power vector method, J(0) and J(45) values, and linear regression models were used to assess the association between age and astigmatism.

Results: The study evaluated the keratometry values in 1430 eyes (827 patients) with a median age of 75 years (range 16 to 98 years). The corneal astigmatism was 1.00 diopter (D) or higher in 45.45% of eyes. The magnitude of corneal astigmatism was positively correlated with age (ρ = 0.126, P = .000). A trend toward increasing against-the-rule astigmatism with age was found by linear regression models; the per-year increase in age was associated with a J(0) decrease of 0.016 D in right eyes and 0.018 D in left eyes (both P = .000). No association was found between age and J(45).

Conclusions: Most eyes having corneal astigmatism of 1.00 D or greater could be covered by the range of the cylindrical power of the toric IOLs available on the market. Against-the-rule corneal astigmatism of relatively younger cataract surgery candidates should be managed more aggressively.

Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.