CP2 learning objectives book Flashcards
Eyeball Anatomy
Homonymous hemianopia due to lesions of optic tract or lateral geniculate body (trauma or vascular)
- Superior quadrantiopia temporal lobe lesion
- Inferior quadrantiopia parietal lobe lesion
Bitemporal hemianopia due to lesion at optic chiasm
- Bitemporal superior quadrantinopia pressure from below chiasm commonly pituitary tumours
- Bitemporal inferior quadrantinopia pressure from above chiasm eg. Cranipharyngioma, meningioma, carotid aneurysm
Glaucomatous defects due to arcuate scotoma
Enlarged blind spot eg. papilloedema or myopic periparllary atrophy
Central scotoma eg. macular degeneration, optic neuritis or toxic amblyopia
Peripheral field constriction eg. Glaucoma, retinitis pigmentosa, poisons, bilateral occipital lobe infarcts, hysteria
Altitudinal defect eg. Ischaemic optic neuropathy, occlusion 1st order branch retinal artery or vein
Defect crossing vertical/horizontal axes retinal pathology – eg. detachment
Eye Wall Histology
Ophthalmoscopy
- Red reflex? - possibly cataracts if not
- pupils dialated? - 1% tropicamide
- get them to look straight ahead and don’t cross their midline or their focus will change
- hand on forehead to guage distance
- Follow vessel to disc and inspect pallor and cup
- inspect vessels and peripery
- look straight at you for macular
- inspect anterior segment by changing fundoscope focus
Visual Field Defects
Eyelid Movement
The eyelid movements are controlled by 3 muscles:
- Orbicularis oculi CN VII closing
- Levator palpebrae superioris CN III opening
- Superior tarsal muscle sympathetic opening
Reflex motor adjustments in response to visual stimuli happen at
TECTOSPINAL TRACT
Also other pathways lead to regulation of pupillary aperture regulated by state of arousal via the reticular formation dependent upon incident illumination
Relevant afferent pupillary defect (RAPD) differential
- Optic nerve ischaemia, optic neuritis, compression, asymmetric glaucoma
- Central retinal artery or ischaemic central retinal vein occlusion
- Large retinal detachment
Contact lens assessment
- Discuss why they want
- carry out normal refractive assesssment for spectacles
- keratometry to measure cornea curvatures and assess astigmatism present
- slit lamp for health of cornea, lids and tear film
- trial lens for fit
- then lens with correct refraction
Contact Lens Complications
- Giant papillary conjunctivitis (GPC)
- Corneal abrasion
- Infective keratitis
- Corneal ulcers
- Neovascularisation
- Corneal hypoxia
- Solution hypersensitivity
Meathods of measureing VA
- Colour vision Ishihara chart
- Visual fields Humphries or Hendersons charts important in Glaucoma
- Contrast sensitivity Pelli Robson chart useful in early cataracts
- Electrodiagnostic electrical stimulus to observe brains response
Bony Orbit Anatomy
Peri-Orbital Vessels
Describe the optic disc
the three C’s
- colour
- contour
- cup
What are Drusen, Exudates and cotton wool spots
- Drusen are; small focal thickenings of Bruch’s membrane the layer that the RPE – retinal pigmented epithelium lies one of the earliest signs of dry macular degeneration widespread yellow discolouration deep to retinal blood vessels is more indicative of wet macular degeneration and there may be involvement of the RPE producing pigmented areas
- Exudates appear as if salt/sugar has been sprinkled on the retina (well defined) they represent lipoprotein material that has been deposited on the retina due to fluid that has leaked from the vasculature
- Cotton wool spots are poorly defined and are micro infarcts of the nerve fibre layer of the retina
