Ophthalmology Flashcards
Painless monocular visual loss that suddenly resolves with normal examination findings?
Amaurosis fugax (TIA)
What retinal changes are seen in diabetic retinopathy on ophthalmoscopy?
Bilateral hard exudates, bilateral cotton wool spots
What is acute closed-angle glaucoma?
A sudden increase in intra-ocular pressure (affecting one eye)
How does acute closed-angle glaucoma present?
1) Excruciating pain in the affected eye at rest
2) Nausea
3) Visual haloes
4) Blurred vision
5) Red eye with pupillary abnormalities
What does the eye look like in acute closed-angle glaucoma?
Red eye with pupillary abnormalities
What is anterior ischaemic optic neuritis?
1) Complication of giant cell/temporal arteritis
2) Involvement of the ophthalmic artery causes spasm, occlusion and subsequent irreversible ischaemia of the retina
Which ophthalmic condition is a complication of giant cell/temporal arteritis?
Anterior ischaemic optic neuritis
How does anterior ischaemic optic neuritis present?
1) Painless monocular visual loss - irreversible, doesn’t resolve like TIA
2) History of GCA symptoms (e.g. scalp tenderness, jaw claudication, weight loss)
What would ophthalmoscopy show in anterior ischaemic optic neuritis?
Chalky white and swollen optic disc
What is the difference between anterior ischaemic optic neuritis and amaurosis fugax?
Both have painless monocular visual loss but in anterior ischaemic optic neuritis this does not spontaneously resolve and is irreversible
Chalky white and swollen optic disc?
Anterior ischaemic optic neuritis
What are the two causes of vitreous haemorrhage?
1) Diabetic eye disease - causes abnormal blood vessels which bleed into the vitreous humour
2) Retinal tears - bleed into the vitreous
What is a vitreous haemorrhage?
Bleeding into the vitreous humour
What would you see in ophthalmoscopy of vitreous haemorrhage?
Ophthalmoscopy would not be possible in the affected eye in large bleeds, as the retina is obscured
How does vitreous haemorrhage present?
Blood in the eye/on ophthalmoscopy, visual loss that would not return spontaneously, signs of diabetic eye disease or retinal tears
What is retinal detachment?
When the sensory retina peels away from the underlying pigmented retinal epithelium
What can cause retinal detachment?
1) Tear in the retina allowing fluid behind the top layer
2) Tugging of the retina by fibrous tissue in the overlying vitreous humour
How does retinal detachment present?
1) Painless visual loss (irreversible but surgery can reduce the extent of damage)
2) History of preceding flashes of light - as the detaching retina tugs on the optic nerve
3) History of floaters - as blood and debris collect in the vitreous
Which part of the optic pathway is disrupted in monocular visual loss?
Optic nerve
Which two parts of the optic pathway can be disrupted in contralateral homonymous hemianopia i.e. nasal field of one eye and nasal field of the other eye?
1) Optic tract (running from the optic chiasm to the ipsilateral geniculate body of the thalamus)
2) Optic radiation (backward extension of the optic tract - from the lateral geniculate body of the thalamus to the ipsilateral primary visual cortex)
Which part of the optic pathway is disrupted in bitemporal hemianopia?
Optic chiasm (here the nasal fibres of each eye cross the midline to join the temporal fibres of the contralateral eye) e.g. pituitary tumour
Which fibres of the optic radiation pass through the temporal lobe?
The fibres that carry visual stimuli from the lower retina (which receives stimulation from the upper half of the visual fields)
Which fibres of the optic radiation pass through the parietal lobe?
The fibres that carry visual stimuli from the upper retina (which receives stimulation from the lower half of the visual fields)
A lesion in what location would cause a contralateral homonymous superior quadrantanopia?
Temporal lobe
