Retina Disorders Flashcards
What equipment is used to examine the retina
Biometry
Perimetry
Fundus camera
Optical coherence tomography
What is Fluorescein angiography
a fluorescent dye is injected into the bloodstream. The dye highlights the blood vessels in the back of the eye so they can be photographed.
What occurs in optical coherence tomography
a non-invasive imaging test.OCTuses light waves to take cross-section pictures of your retina
What is electrophysiology
Series of investigations recording electrical signals from the eye, optic nerve and brain
in response to visual stimuli
What is three different electrophysiology investigations
Electroretinogram (ERG)
Electro-oculogram (EOG)
Visually evoked potentials (VEP)
What is the functions of electroretinogram
Measure retina function by recording action potential within the retina
What are a waves and B wavs from electroretinogram
A - from photoreceptors
B - from muller cells
What is the function of electro-coluogram
Measures function of retinal pigment epithelium and photoreceptors
by Measuring resting potential difference between RPE and photoreceptors
What shows the maximum potential difference in electro-oculogram
Light adapted eye
What is the ratio between the light and dark potentials called
ardens ration
What is the normal ratio for light to dark potentials
1.85
so If that ratio is less than 1.85 it indicates a malfunction of the structures from which the potential originates
What is the function if visually evoked potential
Record optic nevre function by measuring electrical activity in the visual cortes in response to either flashing light to a checker board pattern
What does reduced amplitude indicate in visually evoked potential
Reduced cell number in the eye
what is the potentially aetiology if of reduced cell number in the eye
Ischaemia/traumatic optic neuropathy
What does latency indicate in visually evoked potential
Reduced cell function in the eye
What is the potential aetiology of reduced cell function in the eye
Optic neuritis (demyelination)
How do you determine retinal pathology
Visual acuity,
visual fields, colour vision,
RAPD
Fundoscopy
Fluorescein angiography
Optical coherence tomography (OCT)
Electrophysiology
What seven reasons for 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 is the common causes of central retina vein occlusion
Hypertension
Glaucoma
Hyperviscosity
Inflammation
What is the common causes of central retinal artery occlusion
Emboli
Inflammation
What are the two pathologies of ischaemic optic neuropathy
Arteritic - due to inflammation
Non-arteritic - not due to inflammation
What is arteritic ischaemic optic neuropathy associated with
Giant cell arteritis
What is the symptoms of giant cell arteritis
Headache
Scalp tenderness
Jaw claudication
Neck pain
Nausea/anorexia
Loss of vision
How is giant cell arteries diagnosed
Temporal artery biopsy
Raised inflammatory markers
What is the symptoms and sign of optic neuritis
Pain on eye movements
Reduced vision
Red desaturation
Central scotoma
Relative afferent pupil defect
Swollen optic disc
What is eight reasons for 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
What occurs in age-related macular degeneration
Progressive loss of central vision
What is the risk factors for age-related muscular degeneration
Age
Smoking
Diet
What is the two types of age-related muscular degeneration
dry type- (80-90%)
wet type (10-20%)
What occurs in dry type age-related macular degeneration
o cells of the macula become damagedby a build-up ofdeposits called drusen
What occurs in wet type age related macular degeneration
abnormal blood vessels form underneath the macula and damage its cells.
What can be seen in diabetic retinopathy
Can see cotton wool spots, exudates, vascular abnormalities on retina
What the affect of advanced diabetic retinopathy
Damage to the maccula = maculopathy
What occurs in retinal dystrophies
Series of inherited conditions affecting
photoreceptor function leading to progressive loss of vision
What is the different retinal dystrophies
Photoreceptor dystrophies
RPE- dystrophies
Choroidal dysrophies
vitreoretinal dystrophies
What are examples of drug induced retinopathies
Antimalarials
Phenothiazines
Tamoxifen
What is choroidermemia
a rare inherited disorder that causes progressive loss of vision due to degeneration of the choroid and retina which is caused by a lack of RAB Escort Protein-1 (REP-1)
What can treat chorioderaemia
Gene therapy
How does gene therapy work
If defective or missing gene use viral vector to insert replacement gene into host DNA and Replacement gene synthesises protein
What is the benefit o gene therapy in the eye
Show immune privilege - doesn’t reject
Easily accessible
