Abstract
Purpose: :
To objectively measure accommodative ability in a large cohort of adults.
Methods: :
Subjects (N=2443, aged 21-84 years) were participants in the Beaver Dam Offspring Study. A Grand Seiko Autorefractor was used to obtain 3 measures of refractive error: distance correction, and with correction focusing on a near target at 2 and 4.5 diopters. Readings were converted to spherical equivalent (sphere + ½ cylinder) (SE). Participants were classified as myopic (SE ≤ -1.00), hyperopic (SE ≥ +1.00) or emmetropic (SE > -1.00 and < +1.00). At each of the two near point targets, the participant was considered to have lost accommodative ability if the spherical equivalent was ≥ -0.50. Subjects with cataract surgery were excluded.
Results: :
In preliminary analyses 48% of participants did not accommodate at the 4.5D target and 45% did not accommodate at either target. Loss of ability to accommodate increased with age (OR 4.61; 95% CI 4.09-5.20, for each 5 year increase in age). Hyperopes were less likely to have loss of accommodative ability (OR compared to emmetropes, 0.40; 95% CI 0.27 - 0.60). Myopia and sex were not associated with accommodative ability. 11% of subjects 55-64 years and 8% of subjects 65-84 years retained accommodative ability.
Conclusions: :
These measured data indicate that although loss of accommodative ability is very common in aging adults some older subjects retained accommodative ability. Some modifiable factors may be associated with age-related changes in accommodative ability.
Keywords: accommodation • aging: visual performance