The Eye in Systemic Disease Flashcards
what are the cardinal features of neuro-opthalmic disease?
diplopia (eye movement defects)
visual acuity/visual field loss (visual defects)
what is normal intracranial pressure?
15 or less
15-20 abnormal
20 or more is pathological
what is the Munro Kellie hypothesis?
volume of cranial cavity is constant (80% brain, 10% blood, 10% CSF)
what is supranuclear control?
agreement between brain, eyes, limbs - muscles of the eye are at a slight angle.
what occular motility defects most commonly occur?
SO intorsion/depression in adduction
LR palsy - cross eyed
what are the causes of a CN VI palsy?
microvascular
raised ICP
tumour
congenital
which condition can occur in a CN VI palsy?
papilloedema
what can occur in a CN IV palsy?
head tilt due to weak incyclo-torsion
torsion and chin depression
what are the causes of a CN IV palsy?
congenital decompensated
microvascular
tumour
bilateral - trauma
what is the clinical sign of a CN III palsy?
eyes “down and out” and complete ptosis
what are the causes of a CN III palsy?
Microvascular Tumour Aneurysm MS Congenital
cause of a painful CN III palsy?
aneurysm (EMERGENCY)
what is inter-nuclear opthalmoplegia?
most often caused by MS or cerebrovascular disease (due to dysfunction of the medial longitudinal fasiculus); when looking to the side one is normal but one tends to wobble, diplopia when looking to one side
what are the causes of visual field defects?
Vascular disease - CVA
Space occupying lesion (SOL)
Demyelination (MS)
Trauma - including surgical
what types of pathology can you get in the optic nerve?
Ischaemic Optic Neuropathy Optic neuritis – commonly MS Tumours - rare Meningioma Glioma Haemangioma
how do optic nerve defects present?
complete or horizontal visual defects
what is optic neuritis?
inflammation of optic nerve usually due to destruction of the myelin sheath Progressive visual loss (unilateral) Pain behind eye, especially on movement Colour desaturation Central scotoma Gradual recovery over weeks - months