Abstract
Purpose: :
To describe the change in visual acuity over a 15–year period in the Beaver Dam Eye Study cohort.
Methods: :
Persons 43–86 years of age were evaluated at baseline for best–corrected visual acuity after refraction (Log Mar) and other ocular and systemic traits. All living persons were invited to follow–up examinations 5, 10, and 15 years after the baseline examination, and the same procedure was used at each examination for assessing visual acuity. Data from all persons seen at baseline and at least the 5–year follow–up (N=3684) were eligible. Discrete linear logistic models were used to assess cumulative risk.
Results: :
The change in the mean number of letters read correctly over the 15–year interval varied by age (right eyes) from –2.7 (standard deviation [SD] =6.3) in people between 43 and 54 years of age (n=2038) to –17.4 (SD=27.9) in people 75 years of age or older (n=154) at baseline. 10.1% of the population developed impaired vision (20/40 or worse in the better eye), 1.0% developed severe visual impairment (20/200 or worse in the better eye), 9.2% had doubling of the visual angle, and 4.4% had improved vision. People who were 75 years of age or older at baseline were 12.8 times (95% confidence interval [CI] 9.6 to 17.1, P<0.001) as likely to develop impaired vision, 7.8 times (95% CI 5.6 to 17.1, P<0.001) as likely to have doubling of the visual angle, and 17.8 times (95% CI 8.3 to 38.2, P<0.001) as likely to develop severe visual impairment as people younger than 75 years of age. The 89 persons 75 years of age or older residing in a nursing or group home at follow–up were 1.9 times (95% CI 1.1 to 3.2) as likely to have developed impaired vision, 1.1 times (95% CI 0.4 to 3.5) as likely to have developed severe impaired vision, and 2.1 times (95% CI 1.2 to 3.7) as likely to have had a doubling of the visual angle than those not residing in a nursing or group home at follow–up (n=277).
Conclusions: :
These data provide population–based estimates of the cumulative 15–year incidence of loss of vision over a wide spectrum of ages and show that decreased visual acuity in people 75 years of age is a common finding, especially in those who are admitted to nursing or group homes.
Keywords: visual acuity • clinical (human) or epidemiologic studies: natural history • clinical (human) or epidemiologic studies: prevalence/incidence