Ophthalmology Flashcards
P Uvea=
iris + ciliary body + choroid
Production and flow of aqueous humour
Produced by posterior ciliary body, travels through pupil to anterior chamber. Trabeculum and Cansl of Schlemm take back to venous system.
Maintain 10-21mmHg normal pressure on the eye
Differentials for painful loss of vision
GCA, unveitis, keratitis, conjunctivitis, acute angle glaucoma
Differentials for painless loss of vision
Retinal detachment, vitreous haemorrhage, retinal artery occlusion, anterior ischemic optic neuropathy
Red flags for visual loss
Headache (do an ESR if over 50)
Eye movements painful (optic neuritis)
Lights or flashes preceding visual loss (retinal detachment)
“like a curtain descending” (amaurosis fungax, preceding peripheral vision loss)
Poorly controlled DM (virtuous haemorrhage)
Central retinal artery occlusion appearance on fundoscop
Pale retina, macula has cherry red spot. Attenuated blood vessels.
Sudden painless loss of vision, fundoscopy shows many flame haemorrhages in all quadrants: Diagnosis?
Central retinal vein occlusion
Risks for retinal detachment
pathological myopia
Trauma
Previous retinal detachment
Intraocular surgery
Unilateral swelling of optic disc differentials
NIGHT TIC
Neuritis
Infectious
Granulomatous
Hereditary
Toxic
Traumatic
Infiltrative
Compressive
Papilloedema differentials
=see bilateral swelling of optic disc specifically due to raised ICP
Space occupying lesion
Idiopathic intracranial hypertension
Obstructive hydrocephalus
Venous sinus thrombosis
Differentials for gradual loss of vision
glaucoma
AMD
cataracts
Diabetic and hypertensive retinopathy
open angle glaucoma
increased resistance to aqueous outflow leads to slow and Insidious rise in intraocular pressure. May have decreased visual fields and acuity.
Fingins: High IOP
Incteased cup to disc ratio
Scotoma, peripheral field loss, Central sparing
Management of open angle glaucoma
Prostaglandin analogues (reduce aqueous humor production)
Beta blockers
Acute angle glaucoma
Lens pushes against iris, closed angle blocks aqueous drainage. Acute rise in intraocular pressure -> red, painful eye, photophobia, N&V, red haloes
Cloudy cornea and middilated sluggish pupils
Risks for acute angle glaucoma
Hypermetropia
DM
Trauma
Indian ethnicity
Management of acute angle glaucoma
Urgently reduce IOP: IV acetazolamide, pilocarpine and beta blocker
Then laser iridotomy