Estrogen Replacement Therapy and Retinal Vascular Caliber
Received 30 September 2004; accepted 16 November 2004. published online 11 February 2005.
Objective
It is unclear if estrogen replacement therapy (ERT) has an effect on the retinal circulation. In the current study, we examine the association of ERT, female reproductive factors, and retinal vascular caliber.
Design
Population-based cross-sectional study.
Participants
Women participants aged 43 to 84 years living in Beaver Dam, Wisconsin.
Methods
Retinal photographs of participants taken at the baseline examination were digitized, and the diameters of arterioles and venules were measured using a well-established technique. Estrogen replacement therapy and female reproductive factors were ascertained by interview.
Main Outcome Measures
Retinal arteriolar and venular diameters.
Results
Of the 2469 women participants with data for analysis, 10.5% were current users of ERT and 7.4% were past users. After adjusting for age, blood pressure (BP), body mass index, smoking, and other factors, women who were current users of ERT had narrower retinal arteriolar and venular diameters than those who were past users or never used, with mean arteriolar diameters of 167.6 μm for current users, 170.8 μm for past users, and 170.9 μm for those who never used (P = 0.009) and mean venular diameters of 239.9 μm for current users, 244.0 μm for past users, and 243.9 μm for those who never used (P = 0.02). There was a significant trend of increasing narrowing for both arterioles (P trend, 0.01) and venules (P trend, 0.007) with increasing duration of ERT. Associations were somewhat stronger in younger women and women without a history of hypertension and cigarette smoking. Female reproductive factors (e.g., age of menarche and pregnancy) were not associated with retinal vessel diameters.
Conclusions
Estrogen replacement therapy is associated with narrower retinal vessel diameters, independent of BP and other vascular factors.
1Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia
2Singapore Eye Research Institute, National University of Singapore, Singapore
3Department of Ophthalmology, University of Wisconsin, Madison, Wisconsin
Correspondence to Tien Yin Wong, MD, PhD, Centre for Eye Research Australia, University of Melbourne, 32 Gisborne Street, East Melbourne 3002, Australia
Manuscript no. 2004-148.
This study was supported by the National Institutes of Health, Bethesda, Maryland (grant nos.: EYO6594 [RK, BEKK], HL077166-01 [TYW]); the Sylvia and Charles Viertel Clinical Investigator Award (TYW); and the Biomedical Research Council, Singapore (TYW).
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