Contents
Introduction
Macular degeneration (aka age-related maculopathy – ARM) is a condition that causes gradual visual loss, typically in older patients.
It can be split into two types:
- Dry – atrophic
- Slow decline of vision
- Wet – exudative
- More rapid loss of vision
- Can present super-imposed on dry macular degeneration
Wet and dry types may not be distinguishable in the early stages.
Red flags for macular degeneration
- Decrease in central vision (macula)
- Distortion of vision – e.g. distorted lines, letter missing when reading
- Previous visual loss in other eye from macular degeneration
Epidemiology and Aetiology
- Typically patients aged >55
- Smoking
- 3-4x increased risk
- FHx of macular degeneration
- 50% chance if 1st degree relative with ARM
- Diabetes
- Previous ARM in other eye
- Dry ARM
- More common – about 75% of cases
- Changes occur very gradually
- Near and distant vision affected
- Loss is often symmetrical
- Can progress to wet ARM
- Not easily treatable
- Wet ARM
- Vascular proliferation under the retina
- Treatable
- Can causes more sudden and abrupt changes in visual acuity
Presentation
- Decline in visual acuity
- Affects mainly central vision
- Difficulty reading, watching TV or recognising faces
- Distortion of vision – can be tested using an Amsler Grid
- Usual gradual, but can be acute
- Visual fields will be normal
- No pupillary defects, including no relative afferent pupillary defect
- Normal red reflex
Retinal imaging
Characteristic features are visible on fundoscopy and retinal imaging. These include:
Dry:
- “Drusen” – aka soft exudates – pale-ish spots that appear on the retina. These gradually spread as the disease progresses
- Atrophy of the retina – often resulting in loss of pigmentation, and a washed-out appearance of the retina
Wet
- Wet macular degeneration may also cause scarring and haemorrhages
- New blood vessel formation
Management
Dry
- High dose vitamin supplementation – AREDS2 formulation
- e.g. “Macu-vision” or “VisionCare”
- Advise smoking cessation
- Patients with recent decrease in vision that is central, or involves distortion – need to be seen within 1 week by ophthalmologist
- Annual eye examination with optometrist or ophthalmologist
Wet
- Injections of anti-VEGF into the eye – thought to slow the process of inflammation that leads to new vessel formation and destruction of the macula
- Laser therapy targeted at the new blood vessels – can reduce the inflammation associated with the formation of these new vessels
References
- Age related macular degeneration – RACGP
- Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
- Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
- Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy
- Macular Degeneration – Health Pathways