Screening for Retinal Microvascular Abnormalities in 25.000 Human Subjects

Abstract

Abstract: : Purpose: to examine the retinal vessels by the arterio–venous ratio and the incidence of retinal microvascular abnormalities in a telemedical screening setting. Methods: By trained technicians the retinal vessels from the OD and OS were registered by a non–mydriatic fundus camera (45°, Canon, Kowa). A standardized medical history was performed and completed. The images and the data were electronically sent to a web–server (Siemens). By trained technicians the arterio–venous ratio was calculated using the Parr–Hubbard–formula. Trained ophthalmologists evaluated the retinal fundus image using a standardized web–based document. The result of the individual examination was available for the examined subject by a web–based report. From 1.9.2001 to 1.10.2003 in a prospective study 27.234 subjects were examined and evaluated. The mean age was 48 +–8 years. The subjects reported in 27% arterial hypertension, in 26% hyperlipidemia, in 4% coronary heart disease, and in 2.5% diabetes. The arterial and diastolic blood pressure was in average 129±14mHg, and 82±9mm Hg, respectively. Results: The intraobserver– and interobserver– reproducibility (alpha–Kronbach–coefficient) of the measurement of the arterio–venous ratio was 0,97, and 0,798, respectively. The arterio–venous ratio of the retinal vessels (+– standard deviation) was in average 0,83+–0.9. The arterio–venous ratio correlated significantly with the systolic and diastolic arterial blood pressure, age, and body–mass index. Conclusions: The results confirm recently published data, that the arterio–venous ratio depends strongly on age and systemic diseases. The telemedical setting allowed the examination and evaluation of more than 100 subjects per day.

Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • retina • vascular occlusion/vascular occlusive disease