Factors associated with undercorrected refractive errors in an older population: the Blue Mountains Eye Study

To identify characteristics of people with clinically relevant undercorrected refractive errors.

The Blue Mountains Eye Study was a population based survey of 3654 Australians aged 49-97 years. Examinations included a standardised refraction and measurement of presenting and best corrected visual acuity. Clinically relevant undercorrected refractive error was defined as improvement of >/=10 letters (2+ lines on the logMAR chart) in subjects with presenting acuity 6/9 or worse. Associations with a range of demographic and ocular variables were explored, adjusting for age and sex, presented as odds ratios (OR) with 95% confidence intervals (CI).

Undercorrected refractive error was present in 814/3654 subjects (10.2%). Older age (p <0.001), hyperopia (OR 1.45, CI 1.15 to 1.83), longer interval from last eye examination (p <0.001), past occupation as tradesperson (OR 1.64, 1.13 to 3.29) or labourer (OR 2.00, CI 1.39 to 2.89), receipt of government pension (OR 1.47, CI 1.12 to 1.94), and living alone (OR 1.34, CI 1.05 to 1.72) were all associated with undercorrected refractive error. Past or current use of distance glasses (OR 0.25, CI 0.20 to 0.32) and driving (OR 0.67, CI 0.52 to 0.86) were associated with a lower prevalence.

Increasing age and measures of socioeconomic disadvantage and isolation were found to predict undercorrected refractive error. Given the documented impacts from correctable visual impairment, these findings suggest a need to target education and eye care services.