Dc. Wu et al., RETINAL BLOOD-VESSEL WIDTH MEASURED ON COLOR FUNDUS PHOTOGRAPHS BY IMAGE-ANALYSIS, Acta ophthalmologica Scandinavica, 73, 1995, pp. 33-40
The purpose of this paper was to develop a technique using computerize
d image analysis to measure the width of retinal arteries and veins on
color fundus photographs. The width of the retinal vessel was determi
ned from digitized fundus photographs by programs based on edge detect
ion and boundary tracing. The average vessel width was determined at d
ifferent distances or eccentricities from the center of the optic disc
and using various lengths of vessel segment. Measurements of superior
and inferior temporal vessel width for 20 eyes by 2 operators showed
that about 75% of the measurements could be obtained without the use o
f plan points. The average percent coefficient of variation of the mea
surements was 2.17% for 3 measurements of each vessel. This technique
provides a reproducible and objective method for obtaining the followi
ng parameters: the edges of the vessel, the length of the vessel segme
nt to be measured, location of the measurement along the vessel and su
bsequent retinal vessel width. This technique is readily suitable for
application to clinical studies particularly clinical trials.