Age-Related Macular Degeneration Flashcards
What is age-related macular degeneration (ARMD)?
It is defined as a condition in which there is degeneration of the macula, in relation to the ageing process
What is the most common cause of blindless of elderly individuals?
Age-related macular degeneration
What is the macula?
It is the term used to refer to the central retina
What are the four macula layers - in order from top to bottom?
Photoreceptors
Retinal Pigment Epithelium
Bruch’s Membrane
Choroid Layer
What is the pathophysiological cause of age-related macular degeneration?
There is atrophy of the retinal pigment epithelium and degeneration of retinal photoreceptors
This results in the formation of drusen between the retinal pigment epithelium and Bruch’s membrane
What is drusen?
They are defined as yellow deposits of proteins and lipids
How do we differentiate between normal drusen and age-related macular degeneration drusen?
Normal drusen appear small (< 63 micrometers) and hard
Age-related macular degeneration drusen appear in greater quantities and larger (> 63 micrometers)
What are the two classifications of age-related macular degeneration?
Dry Age-Related Macular Degeneration
Wet Age-Related Macular Degeneration
What is the most common classification of age-related macular degeneration?
Dry Age-Related Macular Degeneration
What is dry-age related macular degeneration?
Dry = Drusen
It is defined as non-exudative and non-neovascular macular degeneration, in which there is the presence of asymptomatic drusen formation in the Bruch’s membrane
What can dry age-related macular degeneration progress into?
Wet age-related macular degeneration
What is wet age-related macular degeneration?
It is defined as exudative and neo-vascular macular degeneration, in which there is development of new blood vessels within the choroid layer into the retina – also known as choroidal neovascularisation
These vessels can leak fluid or blood, resulting in oedema and sudden vision loss
What growth hormone causes wet age-related macular degeneration?
Vascular endothelial growth factor (VGEF)
What are the two features of wet age-related macular degeneration?
Angiogenesis
Neovascularisation
What classification of age-related macular degeneration has the worst prognosis?
Wet age-related macular degeneration
What are the nine risk factors associated with age-related macular degeneration?
Older Age > 75 Years Old
Female Gender
White/Chinese Origin
Family History
Hypertension
Diabetes Mellitus
Dyslipidaemia
Smoking
UV Exposure
What are the six clinical features of age-related macular degeneration?
Central Visual Field Loss
Decreased Vision Acuity
Central Metamorphopsia
Photopsia
Visual Glare
Central Scotoma
What visual loss is associated with dry age-related macular degeneration?
Gradual - usually occurring over a period of several years
What visual loss is associated with wet age-related macular degeneration?
Subacute - usually occuring over a period of several days
What is central metamorphopsia?
It is defined as a crooked or wavy appearance of straight lines
What is photopsia?
It is the perception of flickering or flashing lights
What exacerbates the clinical features of age-related macular degeneration?
Low light conditions
What five investigations are used to diagnose age-related macular degeneration?
Amsler Grid Tests
Fundoscopy
Slit-Lamp Microscopy
Ocular Coherence Tomography (OCT)
Fluorescein Angiography
When are Amsler grid tests used to diagnose age-related macular degeneration?
They are the first line investigation
What are Amsler grid tests?
It involves asking individuals to look at a chart, consistent of straight lines and a central back dot, whilst covering one eye at a time
What feature indicates age-related macular degeneration on Amsler grid tests?
Central metamorphopsia
This is when the individual reports a loss of linearity in the grid centrally
What three features indicate age-related macular degeneration on fundoscopy?
Drusen
Choroidal Neovascularisation
Geographic Atrophy
How do drusen appear on fundoscopy?
They appear as yellow areas of pigment deposition in the macular area
How does choroidal neovascularisation appear on fundoscopy?
It appears as well demarcated red patches
What is the gold standard investigation used to diagnose age-related macular degeneration?
Slit-Lamp Microscopy
What three features indicate age-related macular degeneration on slit-lamp microscopy?
Pigmentary Changes
Exudative Changes
Haemorrhagic Changes
What is the gold standard investigation used to diagnose wet age-related macualr degeneration?
Ocular Coherence Tomography (OCT)
What is ocular coherence tomography (OCT)?
It is a non-invasive imaging method which produces a cross sectional view of the retinal layers
What two features indicate wet age-related macular degeneration on OCT?
Macular Oedema
Foveal Dip Loss
When is fluorescein angiography used to diagnose age-related macular degeneration?
It is the second line investigation used to diagnose wet age-related macular degeneration
What is fluorescein angiography?
It involves administration of a fluorescein contrast and imaging of the retina, in order to determine the blood supply to the retina
What two features indicate wet-age related macular degeneration on fluorescein angiography?
Macular Oedema
Choroidal Neovascularisation
When is indocyanine green angiography used to diagnsoe age-related macular degeneration?
This is indicated when the source of leakage is obscured by a retinal haemorrhage, and thus fluorescein may be ineffective
What is the most appropriate next step in cases of suspected age-related macular degeneration?
Opthamoloy Referral
This should be an urgent two week referral in cases where wet age-related macular degeneration is suspected
What are the four management options of dry age-related macular degeneration?
Low Vision Refractory Aids
AREDS2 Vitamin Formula
Smoking Cessation
Hypertension Control
What are the seven vitamins contained in the AREDS2 formula?
Exogenous Antioxidants
Vitamins C & E
Beta-Carotene
Zinc
Macular Pigments
Lutein
Zeaxanthin
What is the most effective management option to slow down the progression of dry age-related macular degeneration?
Smoking Cessation
What are the two management options used to manage wet age-related macular degeneration?
Intravitreal Anti-VGEF Therapy
Laser Photocoagulation
When is intravitreal anti-VGEF therapy used to manage wet age-related macular degeneration?
It is the first line management option
What is the mechanism of action of intravitreal anti-VGEF therapy?
They inhibit vascular endothelial growth factor (VGEF) and slow the development of neovascularisation
Name four intravitreal anti-VGEF therapies used to manage wet age-related macular degeneration
Aflibercept
Ranibizumab
Bevacizumab
Pegaptanib
How are intravitreal anti-VGEF therapy administered to treat wet age-related macular degeneration?
It involves direct injection into the vitreous chamber of the eye once a month
When is laser photocoagulation used to manage wet age-related macular degeneration?
It is the second line management option
What is laser photocoagulation?
It involves the application of heat to destroy abnormal blood vessels within the retina
