Age related macular degeneration

Age-related macular degeneration is the most common cause of blindness in the UK. Degeneration of the central retina (macula) is the key feature with changes usually bilateral.

Traditionally two forms of macular degeneration are seen:

• dry (geographic atrophy) macular degeneration: characterised by drusen - yellow round spots in Bruch's membrane
• wet (exudative, neovascular) macular degeneration: characterised by choroidal neovascularisation. Leakage of serous fluid and blood can subsequently result in a rapid loss of vision. Carries worst prognosis

Recently there has been a move to a more updated classification:

• early age-related macular degeneration (non-exudative, age-related maculopathy): drusen and alterations to the retinal pigment epithelium (RPE)
• late age-related macular degeneration (neovascularisation, exudative)

Risk factors

• age: most patients are over 60 years of age
• smoking
• family history
• more common in Caucasians
• high cumulative sunlight exposure
• female sex

Features

• reduced visual acuity: 'blurred', 'distorted' vision, central vision is affected first. Straight lines may appear crooked or wavy
• central scotomas
• fundoscopy: drusen, pigmentary changes

Investigation and diagnosis

• optical coherence tomography: provide cross-sectional views of the macula
• if neovascularisation is present fluorescein angiography is performed

General management

• NICE guidance suggests referring patients with suspected macular degeneration for ophthalmological assessment within 1 week
• stop smoking
• high dose of beta-carotene, vitamins C and E, and zinc may help to slow down visual loss for patients with established macular degeneration. Supplements should be avoided in smokers due to an increased risk of lung cancer

Dry macular degeneration - no current medical treatments

Wet macular degeneration

• photocoagulation
• photodynamic therapy
• anti-vascular endothelial growth factor (anti-VEGF) treatments: intravitreal ranibizumab