age related macular disease Flashcards
1
Q
what is age related macular degeneration?
A
-a condition where there is degeneration in the macula that causes progressive deterioration in vision
2
Q
what are risk factors for developing age related macular degeneration?
A
- increase in age
- smoking
- white or Chinese ethnic origin
- family history
- CVD
3
Q
what are the two types of ARMD?
A
- dry (90%)
- wet (10%)
4
Q
how does ARMD present?
A
- gradual worsening of central visual field loss
- reduced visual capacity
- crooked or wavy appearance to straight lines
5
Q
how does wet ARMD present differently than dry ARMDR?
A
- dry ARMDR is more common
- wet ARMDR presents more acutely, it presents with vision loss over days and can progress to full vision loss over 2-3 years that is often bilateral
6
Q
what are signs of ARMD?
A
- drusen on fundoscopy
- atrophy of retinal pigment epithelium
- degeneration of photoreceptors
7
Q
what are Drusen?
A
-yellow deposits of proteins and lipids that appear between the retinal pigment epithelium and Bruch’s membrane
8
Q
what are the 4 layers of the macula?
A
- choroid layer (bottom)
- Bruch’s membrane
- Retinal pigment epithelium
- photoreceptors (top)
9
Q
what investigations are done for ARMD?
A
- reduced acuity using a Snellen chart
- Scotoma (a central path of vision loss)
- Amsler grid test that can be used to assess the distortion of straight lines
- Fundoscopy (drusen are key finding)
- Slit lamp bio microscopic fundus examination
- Optical coherence tomography
- Fluorescein angiography
10
Q
what is the management for dry AMD?
A
- there is no specific treatment
- lifestyle management
- avoid smoking
- control BP
- vitamin supplementation has some evidence in slowing progress
11
Q
what is the management for wet AMD?
A
-anti VEGF medications such as ranibizumab, bevacizumab and pegaptanib
12
Q
what is the pathophysiology of wet AMD?
A
- there is development of new vessels growing from the choroid layer into the retina
- these vessel can leak and cause oedema and more rapid vision loss
- a key chemical that stimulates the development of new vessels is vascular endothelial growth factor (VEGF)
