secondary care Flashcards
what is loss of RG colour vision and indicator of
optic neuritis
direct/consensual light pathway
optic nerve -> pretectal nucleus -> edinger-westphal nucleus (ipsilaterally and contralaterally) -> CN III (ipsi+contra) -> pupil constriction
what pupil reaction is seen in neurosyphilis
pupil doesn’t react well to light (i.e. doesn’t constrict) but does accommodate
what is the effect of cocaine on pupils (and how does it occur)
blocked the reuptake of NA in sympathetic neurons => repeated sympathetic stimulation -> pupils dilate
2 types of CN III palsy and which is an emergency
pupil sparing vs pupil involving
pupil involving is an emergency
superior vs inferior quadrantinopia lesions
PITS - parietal inferior, temporal superior
what diplopia is seen in 4th nerve palsy an what might a pt do to compensate
vertical/tilted diplopia -> pt may have a compensatory head tilt
3 things to comment on about the optic nerve
cup, colour, contour
what drug class is a risk factor for glaucoma
steroids
what is a pinhole used to check in a visual acuity exam
whether the problem is refractive (gets better w pinhole, fixable w glasses) or due to non-refractive factors (corneal problems, glaucoma etc.)
what 3 things are tested for in pupil exam
- direct and consensual light reflex
- swinging light test
- accommodation
function of ocular oblique muscles
look in
what symptom may be seen in lateral rectus palsy
compensatory head turn -> head turned inorder to diminish diplopia
why is the eye in the down and out position in CN III palsy
only LR and SO function -> LR is stronger than SO and so pulls the eye out (even tho SO pulls it in) and then SO pulls it down
what is the primary function of the superior oblique (when looking straight ahead)
intorsion
what is the likely cause for a CN IV palsy
trauma to the head (the nerve has a long journey through the brain)
5 conditions that may cause and increase in size of the blind spot
- glaucoma
- papilloedema
- CRVO
- CRAO
- optic neuritis
how to tell where in the optic tract tell is a lesion causing HH arises from
field defect congruity -> if less symmetrical between the eyes then more likely to be an anterior lesion, if symmetrical then more likely to be posteior lesion
what visual field defect is likely to arise from a pit gland tumour
bitemporal superior quadrantinopia
5 causes of asymmetrical hemifield loss
- optic neuritis
- inf. BRVO/BRAO
- glaucoma
- inf. space occupying lesion
- retinal detachment
what daily function may someone w CN IV palsy struggle with?
reading or walking down stairs -> can’t brings eyes in + down
4 fundoscopy findings of hypertensive retinopathy
- AV nipping;
- hard exudates/cotton wool spots;
- silver wiring;
- optic disc swelling
what is retinitis pigmentosa
pigment deposit in the periphery of the retinal casing damage to rods
where is the macula found on fundoscopy
the area between the temporal branch retinal veins
what does retinitis pigmentosa present with
night blindness - loss of rods
retinitis pigmentosa fundoscopy findings (3)
classic clinical triad:
1. arteriolar attenuation;
2. retinal pigmentary changes (could be either hypopigmentation and/or hyperpigmentation in form of bone-spicule and pigment clumpings)
3. waxy disc pallor
causes of papilloedema (7)
papilloedema must arise from raised ICP - this can be due to many causes:
- malignant HTN
- glaucoma
- chronic CO2 retention
- venous sinus thrombosis
- metabolic hypocalcaemia;
- acute altitude sickness;
- zero gravity
