AGE RELATED MACULAR DEGENRATION
Terms in this set (20)
What is the normal function of the macular?
The central part = fovea, responsible for fine resolution.
What are the 2 types of age related macular degeneration?
What is the difference between wet and dry?
Dry = slow progressive deterioration in visual function
Wet = Growth of new and abnormally located vessels underneath the retina causes a sudden loss of vision by leakage of fluid or haemorrhage.
What is the normal function of the retinal pigment epithelium?
Removal and processing of the used discs of the photoreceptor outer segments.
What happens when the waste products build up?
Undigested lipid products e.g. the pigment lipofuscin accumulate in the RPE and then transferred to Bruch's membrane.
Discrete yellow lesions called drusen.
What is the pathological process in dry AMD?
Cells in the retinal pigment epithelium gradually atrophy and die
Waste products of rods and cones aren't cleared properly.
What does dry AMD look like on ophthalmoscopy?
Drusen at the macula
How can you tell the difference between drusen and diabetic retinopathy?
Drusen look like cotton wool spots, but in dry AMD there won't be any dot haemorrhages.
How does a patient with dry AMD present?
Gradual loss of central vision, peripheral vision maintained.
What is the pathological process behind wet AMD?
Rods and cones degenerate
There is new blood vessel formation: A choroidal neovascular membrane (CNVM) grows from the choroidal layer towards the retina.
What does wet AMD look like on ophthalmoscopy?
Disc like lesion with haemorrhage, drusen and atrophy at the centre with exudate and haemorrhage at the periphery.
Elevated retina overlying CNVM.
How might a patient with wet AMD present?
Severe visual loss over a short period of time.
What causes the visual loss in wet AMD?
Bleeding of fragile blood vessels.
How does a macular scar form in wet AMD?
Spontaneous involution of CNVM,, large scar left behind.
Severely impaired vision.
How is it investigated?
Why is fluoresceine angiogram done?
To determine where the CNVM is and whether the patient will benefit from laser treatment.
What is OCT?
Ocular Coherence Topography.
How is dry AMD treated?
Untreatable - Adaptations, magnifiers, large print, refraction (optician and glasses)
How is wet AMD treated?
How are biologics treated?
Injections into the eye to preserve vision.