Abstract
Purpose: :
Evaluation of repeatability and short term varaibility of semi–automated measurements of retinal vascular geometry (RVG), using novel computer algorithms in normal and diabetic subjects.
Methods: :
Digital fundus images of 30 diabetics and 30 normal subjects were evaluated. RVG measurements included bifurcation angles and junction exponents. Intra and inter–observer repeatability were assessed. Short–term individual variability of measurements was analyzed by repeat photography on the same day and at one week.
Results: :
In 960 images, Intra and Inter–observer repeatability were 5.1° and 5.8° respectively. Short–term individual variability was 5.4° in normal and diabetic subjects. (Kappa=0.74)(95% CI=0.65–0.83)
Conclusions: :
This novel computer algorithm for semi–automated analysis of retinal vascular geometrical measurements is reliable and repeatable. Bifurcation geometry does not vary significantly in the short term. It can thus be used to detect and monitor changes in vascular measurements in future comparative studies
Keywords: imaging/image analysis: non-clinical • retina • imaging/image analysis: clinical