Power Vector Analysis of Refractive, Corneal, and Internal Astigmatism in an Elderly Chinese Population: The Shihpai Eye Study

Abstract

Astigmatism affects approximately three quarters of the Chinese population aged 65 years and older in Taiwan. With increasing age, the prevalence of astigmatism increases, and refractive and corneal astigmatism shift toward ATR. Continuous corneal changes appear to be responsible for the age trend in refractive astigmatism. The severity of lens opacity plays only a minor role in the change of internal astigmatism.

Analysis of anterior corneal astigmatism before cataract surgery using power vector analysis in eyes of Korean patients

“…These agerelated changes in astigmatism reportedly are influenced by changes in the cornea. 11 In a study by Liu et al, 15 most changes in refraction astigmatism pushed the condition toward ATR over the course of corneal aging. Furthermore, the age-related shift toward ATR from WTR was affected by physiologic .…”

“…15 Patient data were divided into 8 age groups to assess agerelated changes in anterior corneal astigmatism; data for men and women were analyzed separately to determine whether there were sex-based differences.…”

The visual and functional impacts of astigmatism and its clinical management

“…Estimates of astigmatic prevalence in the population vary depending on the definition of astigmatism used, and the age and ethnicity of the population examined, although most studies indicate that low levels of astigmatism (≤0.50 D) occur commonly, while high astigmatism (>3.00 D) is rare. A large number of studies have documented consistent changes in the prevalence of ocular astigmatism with age ( Figure ) . In infancy a relatively high prevalence of ocular astigmatism is typically reported, with the magnitude of astigmatism usually reducing over the first few years of life .…”

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

“…The J 45 value refers to a cross-cylinder set at 45-degree and 135-degree, representing oblique astigmatism. 10 Bivariate correlations were evaluated using the Spearman rank correlation coefficient for nonnormally distributed variables. Linear regression models were used to assess the associations between age and astigmatism.…”