Geographic Atrophy

Abstract

Purpose There is a lack of agreement regarding the types of lesions and clinical conditions that should be included in the term “geographic atrophy”. Varied and conflicting views prevail throughout the literature and are currently used by retinal experts and other health care professionals. Methods We reviewed the nominal definition of the term “geographic atrophy” and conducted a search of the ophthalmological literature focusing on preceding terminologies as well as the first citations of the term “geographic atrophy” secondary to age-related macular degeneration (AMD). Results According to the nominal definition, the term “geography” stands for a detailed description of the surface features of a specific region, indicating its relative position. However, it does not necessarily imply that the borders of the region must be sharply demarcated or related to any anatomical structures. The term “geographical areas of atrophy” was initially cited in the 1960s in the ophthalmological literature in the context of uveitic eye disease and shortly thereafter also for the description of variants of “senile macular degeneration”. However, no direct explanation could be found in the literature as to why the terms “geographical” and “geographic” were chosen. Presumably the terms were used as the atrophic regions resembled the map of a continent or well-defined country borders on thematic geographical maps. With the evolution of the terminology, the commonly used adjunct “of the retinal pigment epithelium” was frequently omitted and solely the term “geographic atrophy” prevailed for the non-exudative late-stage of AMD itself. Along with the quantification of atrophic areas, based on different imaging modalities and the use of both manual and semi-automated approaches, various and inconsistent definitions for the minimal lesion diameter or size of atrophic lesions have also emerged. Conclusions Reconsideration of the application of the term “geographic atrophy” in the context of AMD appears to be prudent given ongoing advances in multi-modal retinal imaging technology with identification of various phenotypic characteristics, and the observation of atrophy development in eyes under anti-angiogenic therapy.

Green-Light Autofluorescence Versus Combined Blue-Light Autofluorescence and Near-Infrared Reflectance Imaging in Geographic Atrophy Secondary to Age-Related Macular Degeneration

“…G eographic atrophy (GA) is the non-neovascular late-stage manifestation of AMD. 1,2 Currently, no approved therapy is available for GA while multiple interventional clinical trials are ongoing. 3 Atrophy of the outer retina and RPE are characteristic for GA and also may develop in the presence of the neovascular manifestations (choroidal neovascularization) leading to a significant long-term vision loss despite treatment with anti-VEGF agents.…”

Prognostic Value of Shape-Descriptive Factors for the Progression of Geographic Atrophy Secondary to Age-Related Macular Degeneration

“…[5][6][7][8][9][10] The term GA in the context of AMD (or "senile macular choroidal degeneration") was originally introduced by Gass in 1970 to describe the funduscopic appearance of circumscribed areas of outer retinal atrophy. 5,11,12 Histologically, GA is characterized by loss of retinal pigment epithelium (RPE) as well as a degeneration of the outer layers of the neurosensory retina and the choriocapillaris. 13,14 Over time, foci of GA tend to slowly enlarge and coalesce with an eventual involvement of the fovea.…”

“…13,14 Over time, foci of GA tend to slowly enlarge and coalesce with an eventual involvement of the fovea. 5,11 Among other pathogenetic mechanisms, chronic inflammatory processes, excessive lipofuscin accumulation, complement system dysregulation, and vascular factors have been implicated in the development of AMD. 9,14,15 On fundus autofluorescence (FAF) imaging, areas of GA are clearly defined due to RPE degeneration and the absence of therein contained fluorophores allowing for semi-automated detection and area quantification of atrophic lesions.…”

Beyond Retinal Layers: A Deep Voting Model for Automated Geographic Atrophy Segmentation in SD-OCT Images

“… 5 Thus, automatic detection and characterization of retinal regions affected by GA is a fundamental and important step for clinical diagnosis, which could aid ophthalmologists in objectively measuring the regions of GA and monitor the evolution of AMD to further make treatment decisions. 6 , 7 GA characterization generally requires accurate segmentation. Manual segmentation is time consuming and subject to interrater variability, which may not produce reliable results especially for large data sets.…”