Glaucoma Flashcards
(26 cards)
What is glaucoma
Refers to the optic nerve damage - often from raised intraocular pressure
Two types of gluacoma
Open angle and closed angle
Causes of raised intraocular pressure
Blockage in aqueous humour
Pathophysiology of open angle glaucoma
Gradual increase in resistance through the trabecular meshwork, so aqueous humour struggles to exit the eye
Pathophysiology of acute angle-closure glaucoma
iris bulges forward and seals off the trabecular meshwork from the anterior chamber so pressure builds up quickly
Risk factors for open angle glaucoma
Increasing age, family history, black ethnic origin, nearsightedness (myopia)
Presentation of open angle glaucoma
Asymptomatic for a long time
Peripheral vision worsens (tunnel vision)
Gradual onset of fluctuating pain, headaches
Blurred vision
Halos around lights particularly at night
What can you see on the optic disc from the increased pressure
Cupping
How to measure intraocular pressure
Non-contact tonometry and Goldmann applanation tonometry
Three investigations to diagnose open angle glaucoma
Goldmann aplanation tonometry, fundoscopy, visual field assessment
Three results of investigations to diagnose open angle glaucoma
Raised intraocular pressure, optic disc cupping and optic nerve health, peripheral vision loss
First line management of open angle glaucoma
Prostaglandin analogue eye drops
What do prostaglandin analogues do
Increase uveoscleral outflow
Options for management of open angle glaucoma which reduce aqueous production
Beta blocks
Carbonic anhydrase inhibitors
Sympathomimetics
Eg of beta blockers
Timolol
Eg of carbonic anhydrase inhibitors
Dorzolamide
Eg of sympathomimetics
Brimonidine
What is an option for open angle glaucoma if eye drops are ineffective
Trabeculectomy
What is the intraocular pressure when treatment is started
24mmHg
Risk factors for angle closure glaucoma
Increasing age, female (4x more), family history, chinease and east asian ethnicity, shallow anterior chamber
Medications which can precipitate acute angle-closure glaucoma
Adrenergic medications - noradrenaline.
Anticholinergic medications - oxybutynin and solifenacin.
TCAs - amitriptyline
Presentation of acute angle-closure glaucoma
Unwell
Severely painful eye
Blurred vision
Halos around lights
Associated headache, nausea and vomiting
Examination findings of acute angle closure glaucoma
Red eye, teary
Hazy cornea
Decreased visual acuity
Dilatation of affected pupil, fixed pupil size
Firm eyeball on palpation
Initial management of acute angle closure glaucoma
Lie patient on their back, give pilocarpine eye drops, give acetazolamide 500mg, give analgesia and antiemetic
