Open AccessLocal Progression Kinetics of Geographic Atrophy Depends Upon the Border Location
Author(s) -
Liangbo Shen,
Mengyuan Sun,
Aneesha Ahluwalia,
Michael M. Park,
Benjamin K. Young,
Lucian V. Del Priore
Publication year - 2021
Publication title -
investigative ophthalmology and visual science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.935
H-Index - 218
eISSN - 1552-5783
pISSN - 0146-0404
DOI - 10.1167/iovs.62.13.28
Subject(s) - geographic atrophy , contrast (vision) , atrophy , ophthalmology , eccentricity (behavior) , retinal , morphology (biology) , fundus (uterus) , confounding , perimeter , mathematics , anatomy , medicine , geometry , biology , physics , optics , statistics , genetics , political science , law
Purpose To assess the influence of lesion morphology and location on geographic atrophy (GA) growth rate. Methods We manually delineated GA on color fundus photographs of 237 eyes in the Age-Related Eye Disease Study. We calculated local border expansion rate (BER) as the linear distance that a point on the GA border traveled over 1 year based on a Euclidean distance map. Eye-specific BER was defined as the mean local BER of all points on the GA border in an eye. The percentage area affected by GA was defined as the GA area divided by the total retinal area in the region. Results GA enlarged 1.51 ± 1.96 mm 2 in area and 0.13 ± 0.11 mm in distance over 1 year. The GA area growth rate (mm 2 /y) was associated with the baseline GA area ( P < 0.001), perimeter ( P < 0.001), lesion number ( P < 0.001), and circularity index ( P < 0.001); in contrast, eye-specific BER (mm/y) was not significantly associated with any of these factors. As the retinal eccentricity increased from 0 to 3.5 mm, the local BER increased from 0.10 to 0.24 mm/y ( P < 0.001); in contrast, the percentage of area affected by GA decreased from 49.3% to 2.3%. Conclusions Using distance-based measurements allows GA progression evaluation without significant confounding effects from baseline GA morphology. Local GA progression rates increased as a function of retinal eccentricity within the macula which is opposite of the trend for GA distribution, suggesting that GA initiation and enlargement may be mediated by different biological processes.