Visual defects - clinical Flashcards
Symptoms of visual loss
- Blurred/out of focus
- Glare
- Distorted vision
- Things look pale
- Shadow
- Floater
Blurred vision
Out of focus/not sharp, no distortion, refractive problem (cornea, lens, shape of eye), macular problem
Glare
Difficulty seeing in bright light, corneal/lens problem (cataract)
Distorted vision
Things look wavy, jumbled up, lines not straight, kink, affects retina (wet macular degeneration, macular hole/pucker, retinal detachment)
Things look pale
Look darker/less colour
- Optic nerve disease (neuritis/compression)
- Retina (wet macular degeneration/central serous retinopathy)
Floater
Opacity in vitreous, vitreous syneresis/post vitreous detachment, vitreous haemorrhage
Cataracts symptoms
Blurred vision, glare, change in refraction, asymptomatic, gradual onset
Retina supply from
Blood - inner retina (diffusion from choroid)
Retinal pigment epithelium maintain environment of photoreceptors
Drusen
Reduced function of RPE
Drusen presentation
Yellow deposits under retina (lipids)
Treatment of cataracts
Phacoextraction with lens implant
Dry ARMD
Age-related macular degeneration, gradual
Dry ARMD signs
Drusen, RPE pigmentation/atrophy, decreased reading vision
Treatment of dry ARMD
Stop smoking, dark glasses protect from bright, dietary changes, low visual aids
Advantages of phacoextraction with lens implant
Vision could be improved near to normal, cataracts will deteriorate, performed under local anaesthetic, rapid rehabilitation
Disadvantages of phacoextraction with lens implant
Risk of serious complication > loss of vision (2%), recovery may be limited, fear of operation, eye may feel swollen and gritty after not painful, topical steroid for 2 weeks after
Causes of central retinal artery occlusion
- Embolic (carotid artery disease/valve disease)
- Giant cell arteritis (anterior ischaemic optic neuropathy)
Metamorphosia
Distorted vision - grid of straight lines appears wavy and parts of the grid may appear blank
Wet ARMD
Choroidal neovascular membrane, rapid loss of vision
Wet ARMD treatment
Intravitreal injection of antiVEGF (vascular endothelial growth facotr), visual loss can be reversed
Full thickness macular hole
Caused by natural movement of eyes only affects central vision > deteriorate
Advantage surgery for FTMH
Close hole, visual improvement variable, performed under local anaesthetic
Disadvantages surgery for FTMH
Risk of not closing (10%), serious complications (1%), cataracts
