Are Myopic Eyes Less Likely to Have Diabetic Retinopathy?
Received 19 May 2009; received in revised form 30 June 2009; accepted 30 July 2009. published online 24 December 2009.
Purpose
Eyes with myopia may be less likely to develop diabetic retinopathy (DR). The relationship between refractive error, ocular biometry, and DR therefore was investigated.
Design
Population-based, cross-sectional study.
Participants
Persons with diabetes from the Singapore Malay Eye Study (SiMES).
Methods
Diabetes mellitus was defined as random glucose of 11.1 mmol/l or more, use of diabetic medication, or a physician diagnosis of diabetes. Spherical equivalent refraction (SE) was assessed using an autokeratorefractometer and subjective refraction. Axial length (AL) and anterior chamber depth (ACD) were measured by IOLMaster (Carl Zeiss Meditec AG, Jena, Germany). Diabetic retinopathy was graded from retinal photographs.
Main Outcome Measures
Any DR was defined by characteristic lesions defined by the Early Treatment Diabetic Retinopathy Study (ETDRS); moderate DR by ETDRS retinopathy severity scores of 43 or higher; and vision-threatening retinopathy by severe nonproliferative retinopathy, proliferative DR, or clinically significant macular edema.
Results
Of 3280 adult Malay participants (78.7% response), 629 persons with diabetes contributed to this analysis. In multivariate analyses adjusting for age, gender, education, height, cataract, hypertension, hemoglobin A1c, and other factors, eyes with myopic SE were less likely to have any DR (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.84–0.96; P = 0.002, per 1-diopter [D] decrease), moderate DR (OR, 0.83; 95% CI, 0.73–0.93; P = 0.001, per 1-D decrease), and vision-threatening DR (OR, 0.77; 95% CI, 0.67–0.88; P<0.001, per 1-D decrease). Eyes with longer AL were less likely to have any DR (OR, 0.86; 95% CI, 0.75–0.99; P = 0.041, per 1-mm increase), moderate DR (OR, 0.80; 95% CI, 0.62–1.05; P = 0.11, per 1-mm increase), and vision-threatening DR (OR, 0.63; 95% CI, 0.40–0.99; P = 0.044, per mm increase). Eyes with deeper ACD were less likely to have moderate DR (OR, 0.32; 95% CI, 0.16–0.64; P = 0.001, per 1-mm increase) and vision-threatening DR (OR, 0.14; 95% CI, 0.06–0.36; P = 0.001, per 1-mm increase).
Conclusions
Myopic refraction and longer AL are associated with a lower risk of DR, particularly vision-threatening retinopathy, without any evidence of a threshold.
Financial Disclosure(s)
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Available online: January 19, 2010.
1Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Republic of Singapore
2Centre for Eye Research Australia, University of Melbourne, Victoria, Australia
3Department of Epidemiology and Public Health, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore
4Centre for Vision Research, University of Sydney, Sydney, Australia
5Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore
Correspondence: Tien Yin Wong, FRCSE, PhD, Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Ave, No. 05–00, Singapore 168751, Republic of Singapore
Manuscript no. 2009-668.
Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Supported by the National Medical Research Council (grant no.: 0796/2003; and Biomedical Research Council grant no.: 501/1/25-5).
ABSTRACT