Retinal Disorders Flashcards
what is Fluorescein angiography?
fluorescent dye is injected into the bloodstream. highlights the blood vessels in the back of the eye
what is Optical coherence tomography?
imaging test that uses light waves to take cross-section pictures of the layers of the retina
what is Electrophysiology?
Series of investigations recording electrical signals from the eye, optic nerve and brain
in response to visual stimuli
(Useful when no evidence of physical disease)
what is an Electroretinogram (ERG)?
Measures retinal function
Records action potentials within the retina
what is an Electro-oculogram (EOG)?
Measures resting potential difference between the RPE and photoreceptors- so measures their function
what are Visually evoked potentials (VEP)?
Records optic nerve function
Measures electrical activity in the visual cortex in response to either a flashing light or a checker board pattern
give examples of conditions where there is a sudden painless loss of vision
Central retinal vein occlusion Central retinal artery occlusion Ischaemic optic neuropathy Stroke Vitreous haemorrhage Retinal detachment Sudden discovery of pre-exisiting unilateral LoV
what are common causes of Central Retinal Vein Occlusion?
Hypertension
Glaucoma
Hyperviscosity
Inflammation
what are common causes of Central Retinal Artery Occlusion?
Emboli (carotids/heart)
Inflammation
what are the two types of Ischaemic Optic Neuropathy?
Arteritic (AION)-due to inflammation
Non-arteritic (NAION)
what evidence implies AION?
Temporal artery biopsy taken from side with headache-raised inflammatory markers
what are symptoms and signs of Optic Neuritis?
Pain on eye movements Reduced vision Red desaturation Central scotoma Relative afferent pupil defect Swollen optic disc
give examples of conditions where there is a Gradual Painless Loss of Vision
Cataract Refractive error Age-related macular degeneration Open angle glaucoma Diabetic retinopathy Hypertensive retinopathy Inherited retinal dystrophies Drug-induced retinopathy
describe age-related macular degeneration
Common
Progressive loss of central vision
Risk factors-Age, Smoking, Poor diet
what are the two types of age-related macular degeneration?
Dry type (80-90%) Wet type (10-20%) (wet type is more aggressive, but treatable)
what are the symptoms and signs of Diabetic Retinopathy?
Asymptomatic till late stage Cotton Wool Spots Exudates Vascular anomalies Maculopathy
what is the treatment of Diabetic Retinopathy?
manage diabetes
laser surgery
eye injections
what is Hypertensive Retinopathy?
damage to the retina and retinal circulation due to high blood pressure
what are retinal dystrophies?
Series of inherited conditions affecting photoreceptor function leading to progressive loss of vision
give examples of retinal dystrophies
Retinitis pigmentosa Cone dystrophy Best’s vitelliform macular dystrophy Stargardt macular dystrophy Sorsby macular dystrophy North Carolina macular dystrophy Choroideraemia Gyrate atrophy
describe Retinitis Pigmentosa
mixed inheritance
Predominantly rod degeneration
Mild field defect that becomes severe at middle age
describe Cone dystrophy
Inheritance-Sporadic (90%)
Photopic ERG reduced, scotopic normal
describe Best’s Vitelliform Macular Dystrophy
Inheritance-Dominant
mass develops on the macula that resembles an egg yolk
affects central vision
describe Stargardt Macular Dystrophy
Inheritance-Recessive (90%)
describe Sorsby Macular Dystrophy
Inheritance-Dominant
describe North Carolina Macular Dystrophy
Inheritance-Dominant
describe Choroideraemia
Inheritance- X-linked recessive
describe Gyrate atrophy
Inheritance-Recessive
what medication can cause Drug-induced Retinopathy
Antimalarials
Phenothiazines
Tamoxifen
