Age Related Macular Degeneration

Question 1

What are the risk factors for ARMD?

Answer 1

Non-modifiable:
* Age (8-10x fold increased risk of developing ARMD for people >90 than those aged 50)
* Family history (risk increased by 50% if direct family memeber has ARMD)
* Gender (female > male - may be due to life-expectancy)
* Ethnicity (white Caucasian high risk)
* Complement Factor H gene

Modifiable:
* Smoking (1 pack/ day increases risk of ARMD by 2-3 times)
* Vascular disease (namely high blood pressure)
* Excessive alcohol consumption (more than or equal to 250g alcohol/week, each gram of alcohol increases systolic blood pressure by 0.24mmHg)
* Diet – encourage px to have balanced diet including macular carotenoids, things such as spinach, kale, broccoli, cabbage. Encourage intake of Omega 3 which is found in oily fish e.g. salmon or mackerel

Question 2

Pathophysiology of ARMD?

Answer 2

• Drusen
  –> Extracellular deposits between RPE & Brusch’s – immune mediated & metabolic by-products from RPE
• ↑number & size of drusen correlated w/ pigmentary abnormalities – can coalesce and cause breakdown in relationship between Brusch’s & RPE
• RPE stops working properly with eventual loss of RPE
• Breakdown of blood retinal barrier
• Blood vessels from Brusch’s grow into retina – causing wet ARMD

Question 3

Symptoms of Dry ARMD?

Answer 3

• Reduced vision – can be gradual –> the vision will be affected even when wearing specs, central vision (usually bilateral)
• Distortion – more of an issue in wet ARMD but can happen in dry ARMD
• Scotoma (in central vision) – missing patch/shadow – caused by loss of tissue and changes happening at v centre of vision
• Scar from wet ARMD may look like dry ARMD –> ask px in H&S –> specifically onset
• Choroidal neovascularisation (CNV) –> new BVs growing towards area of ischaemia
• Haemorrhages - sub-retianl, macular oedema, bright area due to damage of RPE, choroidal vessels visible
• Disciform scar

Question 4

Symptoms of Wet ARMD?

Answer 4

• Reduced vision – sudden –> the vision will be affected even when wearing specs, central vision (usually unilateral due to bleed)
• Distortion – more of an issue in wet ARMD but can happen in dry ARMD
• Scotoma (in central vision) – missing patch/shadow – caused by loss of tissue and changes happening at v centre of vision
• Can present with sudden loss of vision – usually wet ARMD when have had a big bleed for e.g. –> haemorrhage - leakage of blood, RPE becomes damaged so things can go through to retina from choroid
• Choroidal neovascularisation (CNV) –> new BVs growing towards area of ischaemia
• Haemorrhages - sub-retianl, macular oedema, bright area due to damage of RPE, choroidal vessels visible

Question 5

Signs of dry ARMD?

Answer 5

Drusen - centred on macula, describe the height and width in disc diameters (DD), may be hyperpigmentation at macula
Can be soft drusen, more fuzzy edges
RPE hyperpigmentation
Late stages of dry ARMD - geographic atrophy after yrs & yrs –> drusen coalesce forming large areas of atrophy, bright area due to damage of RPE, choroidal vessels visible
Disciform scar

Question 6

Assessments to use to investigate ARMD?

Answer 6

• VA
• Refraction
• Does px have cataract?
• Amsler – look for distortion
• Dilated fundal examination
• OCT if available

Question 7

Dry ARMD Treatment/Management?

Answer 7

None
o Give lifestyle advice – stop smoking, healthy diet, UV protection, Vitamin supplements (only if advanced disease in one eye, it can slow down progression in other)
o Blind/partial sight registration
Monitor with Amsler
Minimize risk factors (smoking, diet, BP, alcohol consumption)
Consider nutritional supplements
Optical aids e.g. magnifiers
Non-optical aids

Question 8

Wet ARMD Treatment?

Answer 8

o Anti-VEGF injections
o Laser – used for pxs who have a variant of macular degeneration called polypoidal choroidal vasculopathy
o Surgery – used in pxs who have sub-macular haemorrhages
 Operation needs to be done within 7-10 days of the bleed happening

Question 9

Who to refer with ARMD?

Answer 9

• Reduced VA
• Macular haemorrhage with pigmentary changes (black pigment at macula)/drusen – large sub-retinal haemorrhage warrants an EMERGENCY REFERRAL
• SRF or IRF on OCT
• New distortion
• Sudden loss of vision

Question 10

Who not to refer with ARMD?

Answer 10

• Asymptomatic pxs or VA >6/9 with drusen, atrophy or pigmentary change only, w/ no evidence of fluid
• Pxs already within system
• Pxs with macular scars who have previously been discharged
• Pxs who don’t want to come – check with px they are comfortable attending

Question 11

Choroidal Neovascularisation (CNV) Risk Factors

Answer 11

If one eye has CNV, the risk factors for it occurring in the 2nd eye include:
> 5 drusen
Large drusen
Pigment clumping
Systemic hypertension
All 4 present: 87% risk of CNV in fellow eye within 5yrs
None present: 7% risk of CNV in fellow eye within 5yrs