Abstract
Purpose: :
To describe the prevalence and change in refraction among persons with type 1 diabetes mellitus (T1DM) in a population-based study.
Methods: :
The population-based Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) examined 996 persons with T1DM over a 25-year period from 1980-1982 to 2005-2007. At each examination, a standardized protocol was followed and best corrected refraction was measured without cycloplegia. Refraction measurements were excluded in these analyses for persons under the age of 20 years and when the eye was aphakic, pseudophakic or had a visual acuity of 20/200 or worse. Myopia was defined as a spherical equivalent less than -0.5 diopters (D). Change in refraction was considered between two consecutive examinations (baseline to 1st follow-up, 1st to 2nd follow-up, etc). Results are similar for right and left eyes, so right eye results will be presented.
Results: :
Participants ranged in age from 3 to 79 years with duration of diabetes ranging from 1 to 59 years at the baseline examination. Refraction was available for analysis in 646 right eyes at the baseline examination. The mean (standard deviation) refraction was -1.5 D (2.2) and 59% of right eyes were myopic. Prevalence of myopia decreased with age (in particular after the age of 45 years). Baseline duration of diabetes and gender were not associated with refraction or presence of myopia after adjusting for age. Higher glycosylated hemoglobin was associated with lower prevalence of myopia. More severe levels of diabetic retinopathy were associated with more myopic refraction and increased prevalence of myopia at baseline. In time-dependent models, older age and longer duration at one visit was associated with a hyperopic change in refraction at the next visit while higher glycosylated hemoglobin at the earlier visit was associated with a myopic change in refraction at the next visit.
Conclusions: :
Age is the strongest predictor of refraction and changes in refraction in persons with diabetes. Glycosylated hemoglobin and diabetic retinopathy level are also associated with refraction.
Keywords: refraction • diabetes • clinical (human) or epidemiologic studies: outcomes/complications