Circularity Index as a Risk Factor for Progression of Geographic Atrophy – Corrected Proof
Objective: To develop a parameter that can assess the relative rate of progression of geographic atrophy (GA) based on the hypothesis that noncircular configuration of the atrophic lesion may be a risk factor for enlargement.Design: Cohort study.Participants: Digitized color photographs of 593 eyes with GA from the Age-Related Eye Disease Study (AREDS).Methods: A novel parameter called the “Geographic Atrophy Circularity Index” (GACI) was developed on the basis of area and perimeter measurements to categorize the irregularity of the shape of GA. The GACI ranges from 0.0 to 1.0 and is categorized into 3 groups: 0.25 (very irregular), 0.25 to <0.75 (Read more...)