Age-related macular degeneration is the most common cause of severe vision loss in individuals aged 50 and older.
The macula is the central area of the retina responsible for central vision, fine visual tasks such as reading, driving, facial recognition, and all other precise visual functions.
AMD occurs in two main forms: the dry form and the wet form. According to estimates, 10–20% of all AMD patients develop the wet form, which is responsible for 90% of cases of severe vision loss due to age-related macular degeneration. In some cases, the dry form can also cause vision impairment, though less frequently.
Symptoms of Age-related Macular Degeneration
The earliest sign of dry AMD is the appearance of transparent spots in the eye known as drusen—yellow deposits in the macular area of the retina.
In contrast, wet AMD is characterized by the growth of abnormal blood vessels under the retina.
These lesions occur as abnormal new blood vessels grow from the choroid layer (beneath the retina) and penetrate Bruch’s membrane—a connective tissue layer between the retina and the choroid. These vessels invade the subretinal space, leading to the formation of scar tissue that replaces the functional macular tissue, resulting in irreversible vision loss.
Typically, dry AMD has no noticeable symptoms. However, in the wet form, patients usually experience central vision impairment such as:
- A central dark spot or distortion in vision
- Perceiving objects as smaller or differently sized in each eye
- In rare cases, visual hallucinations may occur
Causes and Risk Factors for AMD
The primary risk factor is age. However, family history also plays a significant role.
Complications of Age-related Macular Degeneration
Severe and rapid central vision loss can occur in approximately 12% of patients who develop the disease in one eye. Furthermore, 50% of those who develop AMD in both eyes may suffer partial blindness within five years of onset.
Although AMD does not lead to complete blindness, it can significantly restrict daily activities such as:
- Reading
- Watching television
- Recognizing faces
- Navigating unfamiliar environments
Diagnosis of Age-related Macular Degeneration
Diagnosis is based on a fundus examination using an ophthalmoscope. Fluorescein angiography (injecting a dye into the bloodstream) is also used to detect the presence of abnormal blood vessels.
During ophthalmoscopic examination, signs such as subretinal blood or fatty deposits under the retina or retinal pigment epithelium should raise suspicion of abnormal blood vessels. A greenish or grayish area or visible scar tissue in the macular region may also indicate AMD.
Treatment of Age-related Macular Degeneration
Recent large-scale studies have demonstrated that antioxidant vitamins and minerals can help prevent the progression of dry AMD to its more severe wet form. This marks the first proven benefit of nutritional supplements in slowing the development of age-related macular degeneration.
Early detection of AMD is crucial. Prompt referral to a retina specialist can reduce the risk of severe vision decline.
Historically, laser therapy was the only evidence-based treatment, but it was suitable for only a small subset of patients. A more recent and significant advancement is photodynamic therapy, which, although not curative, helps stabilize vision and prevent further deterioration.
Prevention of Age-related Macular Degeneration
To reduce the risk of AMD, it is recommended to:
- Maintain normal blood pressure and manage any other health conditions
- Engage in regular physical activity
- Wear sunglasses and hats when outdoors
- Undergo regular eye exams
- Consult a doctor if any visual changes are noticed