dry and wet age related macular degeneration

Question 1

define age related macular degeneration

Answer 1

most common cause of blindness in the UK

degeneration of the central retina (macula) is the key feature with changes usually bilateral

Question 2

pathophys of age related macular degeneration

Answer 2

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

Question 2

risk factors for age related macular degeneration 5

Answer 2

advancing age

female

smoking

FHx

metabolic syndrome
-hypertension, dyslipidaemia, diabetes mellitus

Question 2

describe dry age related macular degeneration

Answer 2

90% of cases
-also known as atrophic

characterised by drusen - yellow round spots in Bruchs membrane

Question 2

describe wet age related macular degeneration

Answer 2

10% of cases
-also known as exudatiev or neovascualr macular degeneration

characterised by choroidal neovascularization

leaky of serous fluid and blood can subsequently result in a rapid loss of vision

carries the worst prognosis

Question 2

clinical features of age related macular degeneration 7 common

Answer 2

reduction in visual acuity, particulalry for near field objects
-gradual in dry ARMD
-subacute in wet ARMD

difficulties in dark adaptation

overall deterioration in vision at night

fluctuations in visual disturbances which may vary significantly from day to day

also suffer from photopsia (perception of flickering or flashing lights)

glare around objects

visual hallucinations -if part of Charles bonnet syndrome

Question 2

define charles bonnet syndrome

Answer 2

common condition in those whove lost their sight

results in visual hallucinations

Question 2

signs of age related macular degeneration 1 common, 1 dry, 1 wet

Answer 2

distortion of line perception

fundoscopy
-presence of drusen -yellow areas can become confluence in late disease to form a macular scar

in wet ARMD
-well demarcated red patches
-may represent intra-retinal or sub-retinal fluid leakage or haemorrhage

Question 2

investigaitons for age related macular degeneration3

Answer 2

slit lamp

fluorescien angiorgraphy if wet ARMD suspected

ocular coherence tomography
-visualise retina in three dimensions because it can reveal areas of diseases

Question 2

management of age related macular degeneration (1 dry, 2 wet)

Answer 2

dry-not much treatment options
-trial showed anti-oxidant vit A,C and E reduced progression of the disease by 1/3
also avoid smoking, control BP

Wet
-anti-VEGF injected into the eye
-examples randibizuman, bevacizumab
-4wks injection

or laser photocoagulation
-does slow progression of wet ARMD where there is new vessel formation

Question 3

state the four layers of the macula

Answer 3

choroid layer-contain bld vsls provide blood supply to macula

above - bruchs membrane

above- retinal pigment epithelium

above-photoreceptors

Question 4

where do drusen appear

Answer 4

between the retinal pigment epithelium and Bruchs membrane

Question 5

what are drusen made of

Answer 5

proteins and lipids

Question 6

what is the key differnece in wet age related macular degeneration

Answer 6

developmental of new vessels growing from choroid layer into the retina

-these vessels leak and cause oedema and a more rapid loss of vision

Question 7

what chemical causes new vessel formation in age related macular degeneration

Answer 7

vascular endothelial growth factor

Question 8

key visual changes in age related macular degeneration

Answer 8

gradual worsening of central visual feild

reduced visual acuity

crooked or wavy appearance to straight lines