Purchase this article with an account.
R. Fotedar, J. J. Wang, G. Burlutsky, P. Mitchell, Blue Mountains Eye Study; Ten-Year Refractive Changes in an Older Australian Population. Invest. Ophthalmol. Vis. Sci. 2007;48(13):4902.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To examine changes in spherical equivalent (SE) over 10 years in older persons
The Blue Mountains Eye Study examined 3654 residents aged 49+ years in 1992-4, 2335 (75% of survivors) were re-examined after 5 and 1952 (76% of survivors) after 10 years.At each visit, subjective refraction was performed according to a modified ETDRS Protocol. SE was calculated as the sum of sphere + 0.5 × cylinder power. At the 10-year exams, axial length was measured using an IOL master. Only right phakic eyes with best-corrected visual acuity >20/40 (n=1340) were included in this analysis.
Over the 10-year period, the overall change was a hyperopic shift in mean SE among persons younger than 65 years and a myopic shift associated with increasing age among those older than 65 years: the gender-adjusted mean change in SE in persons aged 49 to 54, 55 to 64, 65 to 74, and 75+ years at baseline examination was 0.40 D, 0.33D, -0.02D, -0.6D, respectively. Apart from age, refractive change was strongly associated with baseline nuclear cataract. Eyes with nuclear cataract at baseline had a mean myopic shift of -0.96D, compared to 0.26 D in eyes without nuclear cataract (p<0.001). Baseline refractive status, education levels and the presence of diabetes were not associated with SE changes. The age-adjusted mean change in SE was 0.19D, 0.22D and 0.23D for hyperopic, emmetropic and myopic eyes, respectively (p = 0.8). There was no clinically meaningful change in mean cylinder power over the 10-year period, with mean changes ranging from 0.02D in persons aged 49-54 years to 0.28D in those aged 75+ years, with only 25% of these changes +0.5D or more. There was a 10% increase in "against the rule astigmatism" and a 2% decrease in "with the rule" astigmatism in the 10-year period. Cross-sectional data collected at the 10-year visit showed a reduction in axial length associated with age: the mean axial length was 23.61mm (CI 23.50-23.73) in subjects aged 49-54 years at baseline while it was 23.15mm (CI 22.83-23.47) in those aged 75+ years.
These data confirm a previously reported hyperopic shift in persons younger than 65 years and a myopic shift thereafter, likely due to the development of nuclear cataract. There may also be age-related decreases in axial length.
This PDF is available to Subscribers Only