age related macular degeneration (ARMD)

Question 1

what is the most common cause of blindness in the UK?

Answer 1

age-related macular degeneration

Question 2

what is the key feature of ARMD?

Answer 2

degeneration of the central retina (macula)

usually bilateral changes

Question 3

what is ARMD characterised by?

Answer 3

degeneration of retinal photoreceptors that results in formation of drusen which can be seen of fundoscopy and retinal photography

Question 4

what are the 2 forms of macular degeneration?

Answer 4

1. dry (90%, geographic atrophy)
2. wet (10%, exudative, neovascular)

Question 5

what is dry macular degeneration characterised by?

Answer 5

drusen - yellow round spots in Bruch’s membrane

Question 6

what is wet macular degeneration characterised by?

Answer 6

choroidal neovascularisation

leakage of serous fluid and blood → rapid loss of vision

worst Px

Question 7

what is the more updated classification for ARMD?

Answer 7

1. early ARMD (non-exudative, age-related maculopathy)
   
   • ^{_{drusen and alterations to retinal pigment epithelium (RPE)}}
2. late ARMD (neovascularisation, exudative)

Question 8

what are the risk factors for developing ARMD?

Answer 8

1. advanced age (risk increase 3x for >75 y.o.)
2. smoking
3. fam hx
4. ischaemic cardiovascular risk: HTN, dyslipidaemia, DM

Question 9

how do pts with ARMD typically present?

Answer 9

subacute onset of visual loss with:

• reduction in visual acuity, particularly for near field objects
• difficulties in dark adaptation with overall deterioration in vision at night
• fluctuations in visual disturbance which may vary significantly from day to day
• photopsia (perception of flickering/flashing lights) and glare around objects

Question 10

what are the signs that can be seen for ARMD?

Answer 10

1. Amsler grid testing: distortion of line perception
2. fundoscopy: drusen (yellow areas of pigment deposition in macular area) which may become confluent in late disease to form a macular scar
3. wet ARMD: well demarcated red patches representing intra-retinal or sub-retinal fluid leakage/haemorrhage

Question 11

how do you investigate for ARMD?

Answer 11

1. slit-lamp microscopy
   
   • ^{to identify any pigmentary, exudative or haemorrhagic changes affecting the retina}
2. fluorescin angiography
   
   • ^{if neovascular ARMD suspected, as this can guide intervention with anti-VEGF therapy}
3. ocular coherence tomography (OCT)
   
   • ^{to visualise retina in 3D as it can reveal areas of disease which aren’t visible using microscopy alone}

Question 12

how do you treat ARMD?

Answer 12

1. stop smoking
2. rx recommended in pt with at least moderte category dry ARMD. zinc + anti-oxidant vitamins A, C, E reduces disease progression.
3. anti-VEGF agents to limit wet ARMD progression and stabilise/reverse visual loss e.g. ranibizumab 4 weekly injection.
4. laser photocoagulation to slow progression of ARMD where there is new vessel formation (but there is risk of visual loss).

Question 13

what eye disorder is associated with:

(a) central field loss
(b) peripheral field loss?

Answer 13

(a) ARMD
(b) POAG

Question 14

A 76-year-old woman complains of blurred vision. She has not been to the doctors for many years and describes her self as being otherwise fit and well. Fundoscopy reveals the following.

Similar changes are seen in both eyes. What is the most likely diagnosis?

Answer 14

ARMD