Age-Related Macular Degeneration

Question 1

Describe the deterioration in vision in ARMD? Why does this deterioration take place?

Answer 1

Progressive. Takes place due to degeneration of the macula.

Question 2

What are the two types of ARMD and how common are they? Which carries a worse prognosis?

Answer 2

Wet and dry. 10% of cases are wet, 90% are dry. Wet carries a worse prognosis.

Question 3

What are the four layers of the macula (bottom to top)?

Answer 3

1. Choroid layer - blood vessels supplying macula
2. Bruch’s membrane
3. Retinal pigment epithelium
4. Photoreceptors

Question 4

What are drusen and where are they found?

Answer 4

Common finding on fundoscopy in ARMD. Yellow deposits of protein and lipids between pigment epithelium and Bruch’s membrane.

Question 5

What three macular features are common to wet and dry ARMD?

Answer 5

1. Drusen
2. Atrophy of retinal pigment epithelium
3. Degeneration of the photoreceptors

Question 6

What is different about wet ARMD compared to dry? What causes this change?

Answer 6

Neovascularisation. Caused by vascular endothelial growth factor (VEGF), target of medications.

Question 7

What are the risk factors for developing ARMD?

Answer 7

Increased age, smoking, white/chinese ethnic origin, family history, cardiovascular disease.

Question 8

What are the effects of ARMD on vision and what is the typical presentation (time frame, unilateral/bilateral)?

Answer 8

Gradual worsening central visual field loss, reduced visual acuity, crooked/wavy appearance to straight lines.
Presents acutely with loss of vision over days which can become complete loss over 2-3 years. Starts unilaterally, becomes bilateral.

Question 9

What are the findings on examination in ARMD?

Answer 9

1. Scotoma
2. Drusen on fundoscopy
3. Reduced acuity

Question 10

What are the diagnostic tools used for ARMD?

Answer 10

Slit-lamp biomicroscopic fundus examination, optical coherence tomography, fluorescein angiography.

Question 11

How do you manage dry ARMD?

Answer 11

1. Refer to ophthalmologist.

2. Lifestyle management - quit smoking, control BP, vitamin supplementation.

Question 12

How do you manage wet ARMD?

Answer 12

1. Refer to ophthalmologist.

2. Anti-VEGF medications injected into vitreous chamber once per month, can slow/reverse progression.

Question 13

What are some examples of anti-VEGF medications?

Answer 13

Ranibizumab, bevacizumab, pegaptanib.