REVIEW: Retinal Vessel Image set for Estimation of Widths

The first observer (O1) is an ophthalmic specialist with research interests in automated assessment of diabetic retinopathy and evaluation of retinal vascular geometry; he has five year experience in retinal fundus images analysis.

Observer 1

Observers

The second observer (O2) is a specialist optometrist and a qualified secondary grader for diabetic retinopathy; he has been previously involved with different research projects involving handling and analysis of digital images with tasks for defining vascular and non vascular diabetic lesions.

Observer 2

The third observer (O3) has a satisfactory basic medical background being an experienced laboratory specialist. She received a training session in defining and marking retinal vascular segments before starting independent marking of the selected segments for the experiment. Her initial training set was reviewed and independently assessed by an ophthalmic consultant.

Observer 3

The mean of the measured diameters from the three observers is used as the reference standard (O).

The reference standard

Human observers are subjective and prone to inter-observer and intra-observer variability; thus three independent observer marks are provided, each of whom marks a set of randomly selected vascular segments.