Retinal Vascular Caliber and Risk of Retinopathy in Young Patients with Type 1 Diabetes
Received 31 October 2005; accepted 4 May 2006. published online 06 July 2006.
Objective
To examine the relationship between retinal vascular caliber and incident retinopathy in children and adolescents with type 1 diabetes mellitus.
Design
Hospital-based case–control study with prospective outcomes.
Participants
Cases and controls were selected from a cohort of children and adolescents 12 to 20 years old with type 1 diabetes followed up at a tertiary diabetes clinic. Cases were patients who developed incident diabetic retinopathy (n = 166) after at least 1 year of follow-up (≥2 clinic visits), and controls were patients who had not developed retinopathy (n = 165) after ≥2 years of follow-up (≥3 clinic visits). Baseline retinal photographs of cases and controls were digitized, and retinal vascular calibers were measured using a computer-assisted program by a grader masked to case–control status. These measurements were combined into summary indices reflecting the average arteriolar and venular calibers.
Main Outcome Measure
Development of diabetic retinopathy.
Results
Incident retinopathy cases had retinal arteriolar calibers (mean ± standard deviation [SD], 206.5±18.4 μm) significantly larger than those of controls (200.2±16.5 μm) (P = 0.004) but similar retinal venular calibers (329.1±14.7 μm in cases vs. 326.4±15.1 μm in controls, P = 0.312). After adjusting for age, gender, diabetes duration, glycated hemoglobin levels, blood pressure, body mass index, and pubertal stage, larger arteriolar caliber was predictive of risk of diabetic retinopathy (odds ratio, 1.44 per SD increase in arteriolar caliber; 95% confidence interval, 1.11–1.86).
Conclusion
Larger retinal arteriolar caliber predicts incident retinopathy in children and adolescents with type 1 diabetes, independent of conventional risk factors for retinopathy. Measurement of retinal vascular caliber may provide prognostic information regarding the subsequent risk of diabetic retinopathy.
1Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia.
2The Children’s Hospital at Westmead, University of Sydney, Westmead, Australia.
3Department of Medicine, St. Vincent’s Hospital, University of Melbourne, Melbourne, Australia.
4Singapore Eye Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Correspondence to Tien Yin Wong, FRANZCO, PhD, Retinal Vascular Imaging Centre, Eye Research Australia, University of Melbourne, 32 Gisborne Street, Melbourne, Victoria 3002, Australia.
Manuscript no. 2005-1047.
This research was supported by a Diabetes Australia (Canberra, Australia) Research Trust Grant and National Heart Foundation (Sydney, Australia) Fellowship (KCD); the Ophthalmic Research Institute of Australia, Surry Hills, Australia; and the Sylvia and Charles Viertel Clinical Investigator Award (TYW).
ABSTRACT