Abstract
Purpose: :
While there have been some studies of ocular biometry in Asian populations, there are few such population–based data in Caucasian adults. The purpose is to describe ocular dimensions in persons during the fourth examination phase of the population–based Beaver Dam Eye Study.
Methods: :
A total of 1,976 persons 58–96 years of age, seen from 2003–2005, had ocular biometry measures obtained with partial coherence laser interferometry (IOL Master, Carl Zeiss, Germany). Measures of axial length (AL), corneal curvature (CC) and anterior chamber depth (ACD) were analyzed (data from right eyes used in these analyses). Unless otherwise noted, p–values are from ANOVA and are < 0.001. Comparisons of men and women were adjusted for age.
Results: :
The population mean (standard deviation) for the measures was: 23.69 (1.16) mm for AL; 7.79 (0.27) mm for CC; and 3.11 (0.37) mm for ACD. Axial length was shorter in older people and in women. The AL varied from 23.65 mm and 24.02 mm in 58–69 year old women and men, respectively, to 23.36 mm and 23.69 mm in 80–89 year old women and men, respectively. Women had steeper corneas than men (7.74 mm in women and 7.85 mm in men) but there were no significant differences with age. After excluding participants who had cataract surgery, ACD was shorter in older people and in women. The ACD varied from 3.16 mm and 3.18 mm in 58–69 year old women and men, respectively, to 2.87 mm and 2.97 mm in 80–89 year old women and men, respectively.
Conclusions: :
These are the first population–based ocular biometry results in an adult Caucasian population. The shorter axial length observed in older people and in women has also been observed in Asian populations. This may be important in understanding changes in refraction that also occurs in older adults.
Keywords: aging • anatomy • clinical (human) or epidemiologic studies: prevalence/incidence