Prevalence of corneal astigmatism before cataract surgery

Abstract

Objective To analyze the prevalence and presentation of corneal astigmatism in cataract surgery. Methods Keratometric value were measured before surgery in patients having cataract extraction. Descriptive statistics of keratometric cylinder data were analyzed and correlated by age .rangs. Results In 1502 （31.6%） eyes, no corneal astigmatism was present; in 1816 （38.2%） eyes , corneal astigmatism was 0.5 diopters（D） or below; in 1336 （28.1% ） eyes, corneal astigmatism was between 0.5 and 2.0 diopters and in 99 （2.1%） eyes, it was more than 2.0 diopters .Both the refractive power at horizontal meridians and the prevalence of ＂against the rule＂ astigmatism increased with age （p〈0.05）. Conclusions The prevalence of corneal astigmatism more than 0.5D was in 30.1%. The refractive power at horizontal meridians increase and corneal astigmatism changes from with the rule to against the rule with age. Key words: Cataract; Surgery; corneal astigmatism