Age-Related Macular Degeneration (AMD)

What is Age-Related Macular Degeneration (AMD)?

Age-related macular degeneration (AMD) is the leading cause of severe vision loss in people over 50 in the developed world. It affects the macula — the small central area of the retina responsible for sharp, detailed vision used in reading, driving and recognising faces. AMD does not cause complete blindness, as peripheral vision is preserved, but the loss of central vision can have a profound impact on quality of life. There are two forms: dry AMD (gradual) and wet AMD (faster, treatable).

Symptoms

• Gradual blurring of central vision
• Difficulty reading, particularly in dim light
• Distortion — straight lines appearing wavy or bent (Amsler grid test)
• Objects appearing smaller or further away than they are
• A blank or dark spot in the centre of vision (advanced AMD)
• Colours appearing less vivid

Causes

• Age — the single greatest risk factor; risk increases significantly over 70
• Smoking — doubles the risk of AMD
• Family history and genetic factors
• Cardiovascular disease and high blood pressure
• UV light exposure

Diagnosis

Fundus examination, optical coherence tomography (OCT), fundus fluorescein angiography (FFA) and OCT-angiography to distinguish dry from wet AMD and to assess for new vessel growth.

Treatment

Dry AMD has no curative treatment; AREDS2 nutritional supplements slow progression in intermediate AMD. Wet AMD is treated with intravitreal anti-VEGF injections (ranibizumab, aflibercept, bevacizumab) — these can stabilise and sometimes improve vision if started promptly. Regular monitoring is essential.