Introduction
Geographic atrophy, also known as age-related macular degeneration (AMD), is a chronic and progressive degeneration of the macula, the central part of the retina responsible for sharp central vision. It is a common cause of blindness in older adults and is characterized by a regional atrophy of the outer retinal tissues, retinal pigment epithelium (RPE), and choriocapillaris.
Occurrence
Geographic atrophy is most common in people over the age of 60 and is typically associated with advanced stages of age-related macular degeneration (AMD). It can occur in one or both eyes and is often bilateral. According to data from 2014, the prevalence rate of geographic atrophy in China according to to to the 2014 data is approximately 1.88 cases per 10,000 people.
Pathology
The exact cause of geographic atrophy is not fully understood, but it is believed that a combination of genetic and environmental factors contribute to its development.Genetic factors, such as variations in the complement factor H gene, have been linked to an increased risk of geographic atrophy. Environmental factors, including smoking, sunlight exposure, and diet, may also play a role.
Clinical Presentation
The clinical presentation of geographic atrophy typically includes slowly blurred vision, central visual field loss, and color vision disturbances. In advanced stages, the central vision may be completely lost, leading to legal blindness. Visual acuity typically declines steadily over time, and there may be a gradual worsening of parafoveal scotomas.
Diagnosis
Geographic atrophy is diagnosed through a combination of clinical examination, fundus photography, and imaging studies, such as fundus autofluorescence (FAF) imaging and optical coherence tomography (OCT). These imaging techniques help to document the progression of geographic atrophy and to monitor the effects of intervention.
Management
Currently, there is no cure for geographic atrophy, and the main approach to management is based on symptomatic treatment. Visual rehabilitation, such as using low-vision aids, is often necessary to improve quality of life. Anti-vascular endothelial growth factor (anti-VEGF) treatments are sometimes used to treat choroidal neovascularization, which can lead to geographic atrophy, but they do not slow the progression of the atrophy itself.
Surveillance and Prognosis
Regular surveillance with optical coherence tomography (OCT) is recommended to monitor the progression of geographic atrophy and to initiate intervention earlier if there is a change in vision or the appearance of new signs. The prognosis for geographic atrophy is generally poor, with a median loss of visual acuity of 20/100 or more in 2 years.
##Geographic atrophy is a significant public health concern that has devastating effects on vision. Advances in imaging and drug development are needed to improve diagnosis and treatment options for this condition.
