Geographic atrophy occurs when the photoreceptors (seeing part of the retina) no longer works and the patient develops a blind spot or spot of poor vision in the macula (see photo). Geographic atrophy is usually a sharply delineated round or oval area of hypopigmentation, or apparent absence of the retinal pigment epithelium (RPE), in which choroidal vessels are more visible than in surrounding areas The most common sequence of events leading to GA is the progression of a large drusen to hyperpigmentation, followed by regression of the drusen, hypopigmentation and ultimately RPE cell death, with development of an atrophic area of retina and underlying choriocapillaris, sometimes preceded by the appearance of refractile deposits.
Geographic atrophy is a type of advanced dry age-related macular degeneration that can lead to irreversible vision loss. The progression of geographic atrophy is gradual and typically occurs over a period of years. At the onset of geographic atrophy, patients may not notice any significant changes in their vision. However, as the disease progresses, patients may experience a gradual loss of their central vision, resulting in difficulty recognizing faces, reading, and performing other daily activities. The size of the atrophic area usually increases over time, and new areas of atrophy usually develop, leading to further vision loss. In some cases, the disease may progress to the point where the entire macula becomes atrophic, resulting in complete and permanent vision loss in the affected eye.
Untreated, many patients with geographic atrophy lose central vision in about three years. Syfovre can decrease the progression of geographic atrophy by about thirty percent. This may prolong central vision in patients who have geographic atrophy. The studies of Syfovre showed that the drug decreased the progression of geographic atrophy compared to patients who are not treated. There are several important considerations you should keep in mind, however, when considering treatment with this drug:
- The drug is given by injection into the eye.
- It must be continued monthly of every other month to have a benefit.
- It does NOT reverse past damage from geographic atrophy.
- It slows progression of geographic atrophy but does NOT stop the progression of geographic atrophy.
- It may increase the risk of developing wet age-related macular degeneration (in eyes that do not already have wet AMD).
Izervay is injected into the vitreous cavity. The medicine wears off and needs to be injected monthly at first. After the first several injections, some patients continue monthly treatment, some patient may elect to treat every other month after initial therapy.
Intravitreal Injections