EYEYEY Flashcards
What may a patient with dry eyes complain of (4)
- grittiness
- dryness
- eyes feeling tired
- wanting to close eyes
what are the snellen chart visual requirements for driving?
at least 6/12 in at least 1 eye
mechanism of Tropicamide 1%
Muscarinic receptor M4 antagonists
blocks the response of the iris and ciliary muscles to cholinergic stimulation
what is tropicamide used for?
dilation of the pupil for ophthalmoscopy
name 2 antimuscarinic receptor antagonists
- tropicamide
- cyclophenolate
name an alpha adrenergic agnoist
phenylephrine
what should you look for evidence of prior to using dilating eye drops?
acute angle closure glaucoma
3 causes of heterochromia iridis
- horners syndrome
- intraocular foreign body
- occular inflammation
what colour will Fluorescein dye stain and fluoresce under blue cobalt light and when?
- green
- in corneal and conjunctival epithelium abrasions
what may white opacities on cornea indicate
corneal ulcer
2 causes of white reflex leukocoria in children?
- retinoblastoma
- retinal detachment
what is a normal cup to disc ratio
0.3
what is the normal colour of a health and well perfused optic cup?
orange-pink rim with a pale centre
what may blurring of the optic disc margins suggest?
papilloedema
Myopia is ___
and
light rays are brought into focus ___ of the retina
short-sightedens
in front of
myopia is corrected by ___
concave lens
cause of myopia include (2)
- eye too long
- converging power of the cornea or lens is too great
individuals with myopia are more susceptible to which conditions? (3)
- primary open angle glaucoma
- retinal detachment
- macular degeneration
Hypermetropia is ___
and
light rays are brought to focus ___ the retina
long sightedness
behind
hypermetropia is corrected by ___ lens
convex
cause of hypermetropia? (2)
- eye is too short
- converging power of cornea or lens is too weak
individuals with hypermetropia are more susceptible to which condition?
Acute closed angle glaucoma
what is Astigmatism?
uneven curvature of the cornea, causing uneven focus
what can astigmatism be corrected by? (3)
- cylinders
- corneal surgery
- laser
5 causes of reduced visual acuity
- Ambylopia
- Refractive errors
- Cataracts
- ARMD
- Optic neuritis
how can a pin hole be used when testing visual acuity with a snellen chart
improvements when using a pin hole suggest there is a refractive element to their poor vision
what are the stages when assessing visual acuity following a patient being unable to read the top line of the snellen chart at 6 metres? (5)
1) reduce distance to 3 metres
2) reduce distance to 1 metre
3) assess if they can count the number of fingers you are holding up
4) assess if they can see hand movements
5) assess perception of light using a pen torch
5 causes of degeneration of fovea
- macular holes
- cone dystrophies
- retinal artery occlusion
- ARMD
- optic neuropathy
4 causes of peripheral visual loss?
- glaucoma
- retinal detachment
- retinitis pigmentosa
- branch retinal artery occlusion
what is a scotoma?
A defect surrounded by normal visual fields; may begin as a gradual enlargement of the blind spot
what visual defect does a lesion before the optic chiasm produce?
Field defect in the ipsilateral eye
what visual defect does a lesion at the optic chiasm produce?
Bitemporal hemianopia
visual field defect a craniopharyngioma produces?
Bitemporal hemianopia with the lower half affected more than the upper half
visual field defect due to lesions after the optic chiasm?
Homonymous field defect (due to image reversal)
right optic tract lesion
left visual field defect
