Geographic atrophy is the advanced form of dry age-related macular degeneration. Areas of the retina and the supporting layer beneath it thin and lose function, producing well-defined patches where vision is absent rather than simply blurred.

The name describes the appearance: on examination and imaging the affected areas have sharp, map-like borders that expand slowly outward over time.

How it differs from earlier dry AMD

Earlier stages of dry AMD involve drusen deposits and gradual thinning, and vision often remains functional for years. Geographic atrophy represents the point at which cells in defined areas have been lost.

The practical difference for patients is the quality of the visual symptom. Blurring can often be partly compensated for with more light or magnification. A patch of atrophy produces a blank or missing area — letters disappear from the middle of a word, or part of a face is simply not there — and magnification does not restore what is absent.

Atrophy typically begins away from the very center and expands. Central vision may therefore be preserved for a considerable period even when substantial atrophy is present nearby, which is why reading can become difficult while visual acuity measured on a chart still appears reasonable.

How atrophy shows itself in daily vision

  • Blank, dark or missing patches within central vision
  • Difficulty reading, with letters or whole words dropping out
  • Needing considerably more light than before, and adapting slowly when moving between bright and dim environments
  • Difficulty recognizing faces while peripheral vision remains normal
  • Reduced contrast sensitivity, making low-contrast text and edges harder to distinguish

Peripheral vision is not affected by geographic atrophy, and orientation and mobility are generally preserved.

Monitoring and measurement

Because geographic atrophy progresses gradually, management centers on accurate measurement of the affected area over time.

  • Fundus autofluorescence is particularly informative — atrophic areas appear dark against surrounding tissue, and the pattern at the borders gives information about how the area is likely to expand.
  • Optical coherence tomography shows loss of the retinal layers and the tissue beneath, and detects any development of fluid that would indicate conversion to wet AMD.
  • Fundus photography documents overall appearance for comparison.

The other purpose of monitoring is to detect conversion to wet AMD, which can occur in an eye with geographic atrophy and which is treated differently and more urgently.

Treatment and management

Treatments that aim to slow the expansion of geographic atrophy have become available in recent years and are given as injections into the eye on a repeating schedule. They are directed at the rate at which atrophy grows rather than at restoring vision that has already been lost, and they are not appropriate for every patient. Whether such treatment is suitable depends on the pattern and location of atrophy, the state of the other eye, and a discussion of what the treatment can and cannot be expected to do.

Alongside this, management addresses modifiable risk factors — smoking cessation in particular — and nutritional supplementation where the stage of disease fits the criteria studied. Some patients with earlier-stage dry AMD are candidates for Valeda photobiomodulation therapy.

Geographic atrophy is an active area of investigation, and clinical trials studying investigational approaches are conducted at this practice. Participation is optional and separate from routine care.

Practical support for daily vision

Low vision rehabilitation is frequently the intervention that makes the most immediate difference to daily life, and it is underused. It focuses on making the most of remaining vision rather than on treating the retina:

  • Magnification, both optical and electronic, and high-contrast reading aids
  • Task lighting positioned to increase contrast without glare
  • Eccentric viewing techniques, which train the use of an unaffected area of retina adjacent to the atrophy
  • Screen reading settings, audiobooks and voice assistance
  • Occupational therapy assessment for home safety and daily tasks

Ask your physician for a referral to low vision services — these are complementary to medical management, not a substitute for it, and are worth arranging early rather than late.

Geographic atrophy: questions patients raise

No. Geographic atrophy affects central vision and does not involve the peripheral retina, so peripheral vision and the ability to move around independently are retained. It can nonetheless make reading, driving and face recognition very difficult, and it is classified as advanced macular degeneration for that reason.

Expansion is usually slow and is measured over years rather than months, but the rate varies considerably between patients and between eyes. Serial autofluorescence imaging is used to measure the actual rate in your eyes rather than relying on averages.

Cells lost to atrophy do not recover, and no current treatment restores vision in an atrophic area. Available treatments are directed at slowing further expansion, which is why they are discussed in terms of what may be preserved rather than what may be regained.

Whether supplementation is appropriate depends on the stage of disease in both eyes and should be reviewed with your physician rather than assumed. The AREDS2 formulation was studied at particular stages of AMD and is not indicated for everyone with the diagnosis.

Geographic atrophy commonly develops in both eyes, though often at different times and rates. The unaffected eye is monitored, and any change in its vision should be reported promptly — particularly distortion, which can indicate conversion to wet AMD rather than atrophy.

That depends on the extent of atrophy, your measured vision and Arizona licensing requirements, and it is a decision to make with your physician rather than on your own assessment. Many patients continue driving in early stages, often with restrictions such as avoiding night driving.

Discuss geographic atrophy with a retina specialist

Accurate imaging establishes how much atrophy is present and how quickly it is changing, which is what treatment decisions rest on. Call (602) 613-5473 or contact our Scottsdale office.