Geographic Atrophy

DefinitionGeographic Atrophy (GA) represents the late stage of dry age-related macular degeneration (d-AMD). It is recognized by sharply defined areas of atrophy of the retinal pigment epithelium (RPE) in the macular region of the eye, but also involves the overlying photoreceptors, as well as parts of the choriocapillaris. In the areas of atrophy underlying choroidal vessels can be seen. The pathophysiology is not fully known. Many different parameters are described to play a role in the development of the disease, e.g. genetic and environmental factors.
Clinical SymptomsProgression rate for GA is slow comparing to neovascular AMD (n-AMD), but disease progression is steady over years. Symptoms vary depending on the involvement of the fovea (center of the macula), which can be spared in an early stage resulting in an appearance known as foveal sparing. Patients commonly describe a decline in visual acuity, contrast sensitivity and in the ability to read. The symptoms are likely to be more severe if the fovea is involved. Scotomas can occur in corresponding areas of atrophy.
Diagnosis and ExaminationsMorphological changes and progression can be monitored using a variety of examinations:
· Slit lamp examination
· Fundus photography
· Infrared reflectance (IR)
· (Quantitative) fundus autofluorescence ((q)FAF)
· Optical coherence tomography (OCT)
Prevention and TreatmentThere is currently no treatment available to reverse the progress of atrophy. Clinical trials focus on interrupting disease progression using a broad variety of approaches, e.g. anti-inflammatory therapy, neuroprotective therapy, lipofuscin and visual cycle inhibitors or choroidal blood flow restoration agents. General disease risk factors like smoking or obesity should be avoided. Nutritional supplements are recommended to prevent development of n-AMD but no delay of atrophy is proven. Management focuses on surveillance and early treatment of occurring n-AMD.