Age-related macular degeneration (AMD)

Question 1

what are the risk factors for AMD?

Answer 1

• modifiable
• Age > 50 (major risk factor)
  FHx of AMD
• Smoking (2x risk)
• HTN and other CVRF
• High antioxidant intake may have a protective effect in some groups

Question 2

what are drusens spots?

Answer 2

extracellular deposits located at the interface between the RPE and Bruch membrane.

Question 3

what are the symptoms of dry AMD?

Answer 3

Gradual central LOV + metamorphopsia

More slowly progressing (gradual vision impairment over months-years)

Question 4

what are the signs of dry AMD?

Answer 4

• Normal or decreased VA
• Drusen (soft, hard) and focal hyper/hypo-pigmentation
• Geographic atrophy (GA) of retinal pigment epithelium (RPE) – severe visual loss uncommon but possible
• Abnormal Amsler grid (central/paracentral scotoma – areas of no vision, or metamorphopsia – straight lines become distorted/wavy)
• RPE clumping
• Blunted foveal reflex

Question 5

what are the symptoms of wet AMD?

Answer 5

Gradual central LOV + metamorphopsia

More rapidly progressing (accounts for majority of visual morbidity)

May have acute painless LOV if sudden macular haemorrhage or further extension of bleeding into vitreous cavity causing vitreous haemorrhage

Question 6

what are the signs of wet AMD?

Answer 6

• Subretinal fluid
• Macular oedema
• Haemorrhage in the retina, subretina and sub-RPE
• Hard exudates
• RPE detachment and tears
• Subretinal fibrosis (chronic, due to CNV)
• Disciform scar (final common pathway of exudative AMD)
• Drusen, RPE atrophy, focal pigmentary changes usually present in fellow eye

Question 7

what is the management of dry AMD?

Answer 7

Control HTN (and ischaemic CVRF)

Smoking cessation

Yearly review (any drusen of any size anywhere + no pigment epithelium detachment (PED)/fibrous scar/geographic atrophy/CNV

Regular home Amsler grid monitoring biweekly
-> return early to clinic if there is change in vision, metamorphopsia, or change in Amsler grid

High dose vitamins and antioxidant supplements (AREDS1/2 formulation) to reduce progression to wet AMD 20-30% at best

Question 8

what is the management of wet AMD?

Answer 8

Control HTN (and ischaemic CVRF)

Smoking cessation

Yearly review (any drusen of any size anywhere + no pigment epithelium detachment (PED)/fibrous scar/geographic atrophy/CNV

**Intravitreal anti-VEGF every 1/12

Question 9

what are the investigations for dry AMD?

Answer 9

Fundoscopy: **Drusen, w/o hard exudates, haemorrhages, macular oedema (IMPT -VEs TO MENTION)

OCT – quantify areas of Drusen and geographical atrophy of RPE

FFA/ICG – evaluate window defects of geographic atrophy (RPE usually acts as physical and optical barrier to dye -> RPE defects appear dark). R/o wet AMD (should not see CNV)

Question 10

what are the investigations of wet AMD

Answer 10

• CT – quantify extent of retinal oedema and thickening
• FFA/ICG - assess exact location of CNV (cannot be seen on fundoscopy due to deepness of choroidal vessels; new vessels will leak dye and hence light up). Useful TRO wet AMD in dry AMD

Question 11

what are the different types of anti VGEF available?

Answer 11

Avastin (bevacizumab): SGD300 (can deduct full amount from Medisave)

Lucentis (ranibizumab): SGD800 (can only deduct SGD300, remainder pay cash)

Eylea (aflibercept): SGD1200 (can only deduct SGD300, remainder pay cash)