Opthalmology Flashcards
What are the causes of sudden visual loss?
Vitreous haemorrhage Retinal artery occlusion Retinal vein occlusion Haemorrhagic wet age related macular degeneration Ischaemic optic neuropathy Pituitary apoplexy CVD Trauma
(retinal detachment and optic neuritis cause rapid but not sudden loss of vision)
How would you describe a persons eye position?
Conjugate or dysconjugate
What are the symptoms and causes of vitreous haemorhage?
Blurred vision, floaters, flashes, sudden visual loss
Reduced red reflex
Dense haemorrhage can completely obscur the retina
Retinal neovascularisation
What are the stages of diabetic retinopathy?
Non-proliferative diabetic retinopathy
- Mild: at least one microaneurysm
- Moderate: haemorrhages, microaneurysm and hard exudates
- Severe (4-2-1): microaneurysms & haemorrhages in all 4 quadrants, venous beading in 2 quadrants, microvascular abnormalities in 1 quadrant
Proliferative diabetic retinopathy
- Neovascularisation
- Preretinal & vitreous haemorrhage
What signs do you get in maculopathy?
Central visual loss
Focal or diffuse macular oedema
Hard exudates and thickening
Siginificant when found close to fovea
Describe the pathophysiology of diabetic retinopathy?
Microangiopathy that results in
a) vascular occlusion
b) leakage of plasma constituents outside of vessels
Vascular occlusion results in retinal ischaemia which leads to angiogenic factors (VEGF) that drive growth of new vessels
How would you manage diabetic retinopathy/maculopathy?
Primary prevention
- Glycaemic control (sudden intensive control can worsen it)
- BP control
- Lipid control
- Smoking cessation
- Diet
Laser therapy- aims to induce regression of new blood vessels and reduce macular thickening
Macular oedema is treated 1st by focal laser burns
Diabetic retinopathy by pan-retinal photocoagulation
Intravitreal steroids used in macular oedema
anti- VEGF- macular oedema
What symptoms would you get with retinitis pigmentosa?
Initially difficulty with night vision and gradual loss of peripheral vision
Age at presentation usually 10-30yrs
Most people retain a central tunnel vision
Name some causes of gradual visual loss?
Cataract Age related macular degeneration Diabetic maculopathy Glaucoma Retinitis pigmentosa Optic atrophy- compressive, toxic, nutritional
How is retinitis pigmentosa inherited?
Can be AD, AR, sex linked recessive, mitochondrial
50% sporadic in UK (no FH likely recessive)
15-20% likely dominant
What syndromes are assoc with RP?
Usher syndrome
Refsum disease
Lawrence- Moon-Bardet-Beidl syndrome
Kearns - Sayre syndrome
What are features of Usher syndrome?
Congenital neurosensory deafness
Retinitis pigmentosa
What are the features of Refsum disease?
Deafness Cerebellar ataxia Peripheral neuropathy Cardiomyopathy Icthyosis Palpable peripheral nerves Retinitis pigmentosa
What are features of Lawrence- Moon- Bardet- Biedl syndrome?
Deafness Polydactyly (extra fingers/toes) Short stature LD Hypogonadism Renal disease Diabetes Retinitis pigmentosa
What are the features of Kearns- Sayre syndrome?
Chronic progressive external opthalmoplegia
Cardiac conduction defects
Retinitis pigmentosa
Inherited as mitochondrial trait