TY - JOUR
T1 - Power vector analysis of refractive, corneal, and internal astigmatism in an elderly Chinese Population
T2 - The Shihpai Eye Study
AU - Liu, Yu Chi
AU - Chou, Pesus
AU - Wojciechowski, Robert
AU - Lin, Pei Yu
AU - Jui-Ling, Catherine Liu
AU - Chen, Shih Jen
AU - Liu, Jorn Hon
AU - Hsu, Wen Ming
AU - Cheng, Ching Yu
PY - 2011/12
Y1 - 2011/12
N2 - Purpose. To investigate age-related trends in refractive, corneal, and internal astigmatism and to assess the association between internal astigmatism and lens opacity in an elderly Chinese population. Methods. A population-based study was conducted among 1360 inhabitants aged 65 years and older in Taipei, Taiwan. Participants underwent measurements of refraction, corneal dioptric power, and slit lamp biomicroscopy with lens grading. A total of 2084 eyes were included in power vector analyses of Cartesian astigmatism (J 0) and oblique astigmatism (J 45) components of refractive, corneal, and internal astigmatism. Results. The crude prevalence of refractive astigmatism (defined as ≥0.75 diopters) was 73.0% based on the right eyes and 76.4% based on the left eyes. The vector values in both refractive J 0 and corneal J 0 tended to be more negative with increasing age (P <0.001), indicating the trend toward against-the-rule (ATR) astigmatism. Corneal J 0 alone accounted for 54% of the variability in refractive J 0. Refractive J 45 increased with age in the right eyes (P <0.001) and decreased slightly with age in the left eyes (P = 0.012). Cortical opacity was associated with internal J 0 (P = 0.025), but the association was weak. Conclusions. 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.
AB - Purpose. To investigate age-related trends in refractive, corneal, and internal astigmatism and to assess the association between internal astigmatism and lens opacity in an elderly Chinese population. Methods. A population-based study was conducted among 1360 inhabitants aged 65 years and older in Taipei, Taiwan. Participants underwent measurements of refraction, corneal dioptric power, and slit lamp biomicroscopy with lens grading. A total of 2084 eyes were included in power vector analyses of Cartesian astigmatism (J 0) and oblique astigmatism (J 45) components of refractive, corneal, and internal astigmatism. Results. The crude prevalence of refractive astigmatism (defined as ≥0.75 diopters) was 73.0% based on the right eyes and 76.4% based on the left eyes. The vector values in both refractive J 0 and corneal J 0 tended to be more negative with increasing age (P <0.001), indicating the trend toward against-the-rule (ATR) astigmatism. Corneal J 0 alone accounted for 54% of the variability in refractive J 0. Refractive J 45 increased with age in the right eyes (P <0.001) and decreased slightly with age in the left eyes (P = 0.012). Cortical opacity was associated with internal J 0 (P = 0.025), but the association was weak. Conclusions. 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.
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U2 - 10.1167/iovs.11-7641
DO - 10.1167/iovs.11-7641
M3 - Article
C2 - 22110083
AN - SCOPUS:84863507245
SN - 0146-0404
VL - 52
SP - 9651
EP - 9657
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 13
ER -