Macular degeneration – age-related – Summary

Age-related macular degeneration (AMD) is the term applied to changes, that occur with ageing and without any other obvious cause, in the central area of the retina (macula) in people 50 years of age or older. Classified according to severity, AMD can range from small drusen to neovascularisation and visual loss.

AMD is the most common cause of blindness in the UK, however it rarely effects people below the age of 60.

Established risk factors for AMD include:
Tobacco smoking
Family history and genetic factors.
White ethnic origin (neovascular AMD only).

Complications of AMD include:
Visual impairment and blindness.
Depression.
Visual hallucinations (Charles Bonnet syndrome).
Falls and fractures.
Limitations in mobility, activities of daily living, and physical performance.
Reduced quality of life.

AMD should be suspected in people 50 years of age or older who present with either of the following symptoms, usually affecting one eye at a time:
Distortion of vision, where straight lines appear crooked or wavy.
Painless loss or blurring of central or near-central vision. The person may describe a black or grey patch affecting their central field of vision (scotoma).
Other symptoms that are less commonly associated with AMD include:
Difficulty reading, driving, or seeing fine detail (such as facial expressions and features).
Light glare.

Loss of (or decreased) contrast sensitivity (the ability to discern between different shades or ‘luminances’).
Size or colour of objects appearing different with each eye.
Showers of floaters or clouding of the visual field caused by vitreous haemorrhage.
Flickering or flashing lights (photopsias).
Visual hallucinations (Charles Bonnet syndrome). These can occur with severe visual loss of any cause, including advanced AMD. Such symptoms are often not reported unless specifically asked about.
Abnormal dark adaptation (difficulty adjusting from bright to dim lighting), and the need for brighter light than previously to read small print.

On examination, visual acuity on a Snellen chart may be normal or reduced. People with AMD may describe breaks, waviness, or missing portions of the lines when looking at graph paper or an Amsler chart.

If AMD is suspected, referral should occur within a week to one of the following:
A fast-track macular clinic or medical retina clinic treatment centre (if available).
A local district general hospital eye service.
An optometrist
Eye Casualty

Management in secondary care includes:
Anti-angiogenic therapies (e.g ranibizumab).
Laser photocoagulation.
Photodynamic therapy (PDT) with verteporfin.

G Mohan.