Age related macular degeneration Flashcards
What is age-related macular degeneration (ARMD)?
ARMD is the most common cause of blindness in the UK, characterized by degeneration of the central retina (macula) and usually bilateral changes.
What are the key features of ARMD?
ARMD is characterized by degeneration of retinal photoreceptors resulting in the formation of drusen, visible on fundoscopy and retinal photography.
What is the greatest risk factor for ARMD?
Advancing age itself is the greatest risk factor for ARMD.
How does age affect the risk of ARMD?
The risk of ARMD increases threefold for patients older than 75 years compared to those aged 65-74.
How does smoking influence the risk of ARMD?
Current smokers are twice as likely as non-smokers to have ARMD-related visual loss, and ex-smokers have a slightly increased risk (OR 1.13).
How does family history affect the risk of ARMD?
First-degree relatives of a sufferer of ARMD are thought to be four times more likely to inherit the condition.
What are other risk factors for ARMD?
Other risk factors include hypertension, dyslipidaemia, and diabetes mellitus.
What are the two traditional forms of macular degeneration?
The two forms are dry macular degeneration (90% of cases) and wet macular degeneration (10% of cases).
What characterizes dry macular degeneration?
Dry macular degeneration is also known as atrophic and is characterized by drusen, which are yellow round spots in Bruch’s membrane.
What characterizes wet macular degeneration?
Wet macular degeneration is also known as exudative or neovascular macular degeneration and is characterized by choroidal neovascularisation, leading to rapid vision loss.
What are the clinical features of ARMD?
Patients typically present with subacute onset of visual loss, reduction in visual acuity, difficulties in dark adaptation, and fluctuations in visual disturbance.
What signs are associated with ARMD?
Signs include distortion of line perception on Amsler grid testing and the presence of drusen on fundoscopy.
What is the initial investigation of choice for ARMD?
Slit-lamp microscopy is the initial investigation of choice to identify changes affecting the retina.
What investigations are used if neovascular ARMD is suspected?
Fluorescein angiography is utilized, often complemented with indocyanine green angiography.
What is the treatment for dry ARMD according to the AREDS trial?
The AREDS trial showed that a combination of zinc with antioxidants A, C, and E reduced disease progression by about one third.
What role does vascular endothelial growth factor (VEGF) play in wet ARMD?
VEGF drives increased vascular permeability, and anti-VEGF agents can limit progression and stabilize or reverse visual loss.
What are examples of anti-VEGF agents?
Examples include ranibizumab, bevacizumab, and pegaptanib, usually administered by 4-weekly injection.
What is the risk associated with laser photocoagulation in ARMD treatment?
Laser photocoagulation can slow progression but carries a risk of acute visual loss, especially in patients with sub-foveal ARMD.
