creation date: 2026-06-27 02:37
tags: Pathologies
Age-Related Macular Degeneration
Background
Definitions
Age-related macular degeneration (AMD) is a degenerative disease of the photoreceptors of the macula and supporting retinal pigment epithelium leading to central vision loss.
Dry AMD: nonexudative, non-neovascular, more common form
Wet AMD: exudative/neovascular, characterized by new vessel formation in and under retina
Risk Factors & Pathogenesis
AMD is the most common cause of severe central vision loss and legal blindness among adults in Western populations.
Risk factors include:
- Older age
- Genetic risk
- Smoking
- Low antioxidant intake in diet
Aging is the most important risk factor, along with genetics, contribute to the development of AMD. Additionally, lipid dyshomeostasis, impaired autophagy, increased oxidative stress, inflammation, iron overload, and accumulation of toxic drusen-associated material are associated with development.
In dry AMD, round, yellow deposits of lipid-rich material (known as drusen) deposit in the retina. These can be visualized on dilated eye exam. In a small proportion of patients, dry AMD may progress to wet AMD.
In wet AMD, new vessels form in and under the retina. These vessels tend to leak resulting in collections of fluids and/or blood in and/or beneath the retina.
Clinical Presentation
Signs & Symptoms
AMD is initially asymptomatic. Visual symptoms can then be used to track progression:
Early stage
- Mild vague visual complaints
- Issues with low contrast
- Issues with adapting from bright to dark environments
- More light needed for reading
Intermediate stage
- Distortion
- Blurriness
- Mild to moderate decreased visual acuity
- More significant loss of contrast sensitivity
- More prolonged dark adaptation times
Advanced stage
- Loss of central visual acuity
- Significant distortion
- Significant central/paracentral scotomas
- Legal blindness
These changes are typically bilaterally, although may be asymmetric. Peripheral vision is typically preserved.
Findings on eye exam include:
- Drusen (dry AMD)
- Subretinal fluid and/or hemorrhage (wet AMD)
- Greyish-green discolouration in the macular area (wet AMD)
History & Physical Exam
Eye exam should be performed, ideally by an optometrist or ophthalmologist.
Diagnosis
Criteria
Diagnosis is made clinically based on characteristic findings on dilated eye exam using slit-lamp.
Staging is completed using the findings listed above.
Work-up
While history generally suffices, acute presentation of vision loss (may be initial presentation for wet AMD) should involve working up other causes of acute vision loss.
Differential
Red Flags / Complications
Untreated AMD may progress to irreversible legal blindness.
Management
General Measures
All patients should be encouraged to:
- Quit smoking
- Switch to a Mediterranean diet
- Avoid excessive alcohol intake
In patients with intermediate dry AMD or advanced AMD, AREDS2 vitamin supplements are recommended as they are thought to reduce progression.
Dry AMD
Dry AMD has limited management options in addition to the general measures. There are novel treatment options developed but efficacy and safety are uncertain.
Wet AMD
The mainstay management of wet AMD is VEGF inhibitor injections to limit progression and possibly reverse vision loss.