Glaucoma Flashcards
What is glaucoma?
Damage to the optic nerve caused by a rise in intraocular pressure
Where is aqueous humour produced by?
The ciliary bodies
Where does aqueous humour drain out of the anterior chamber?
Through to the trabecular meshwork to the canal of Schlemm, which is located at the angle between the cornea and the iris
What is the pathphysiology of open-angle glaucoma?
There is a gradual increase in resistance to flow through the trabecular meshwork
What is the pathophysiology of acute angle closure glaucoma?
The iris bulges forwards and seals off the trabecular meshwork from the anterior chamber, preventing aqueous humour from draining
What are the risk factors for open angle glaucoma?
Increasing age
Family history
Black ethnic origin
Myopia
Hypertension
Cardiovascular disease
Diabetes
Corticosteroid use
What is the onset of primary open angle glaucoma?
Chronic and progressive
What is the presentation of primary open angle glaucoma?
May be asymptomatic
Peripheral vision loss
Fluctuating pain
Headaches
Blurred vision
Halos around lights
How is intraocular pressure measured?
Non-contact tonometry - involved shooting a puff of air at the cornea and measuring the corneal reponse
Goldmann applanation tonometry - involves a device mounted on a slip lamp that makes contact with the cornea and applies various pressures
What investigations are used in the diagnosis of glaucoma?
Goldmann applanation tonometry
Slit lamp assessment
Visual field assessment
Gonioscopy - assess angle between iris and cornea
Central corneal thickness assessment
What is the first line management of primary open angle glaucoma?
Topical prostaglandin analgoue or prostamide
Topical beta blocker
What are the second line management options of primary open angle glaucoma?
Combine a topical prostaglandin analogue or prostamide with a topical beta blocker
Switch to or add in a second line drug:
- Topical sympathomimetic
- Topical carbonic anhydrase inhibitor
- Topical miotic
What is the management of refractory primary open angle glaucoma?
Laser therapy - selective laser trabeculoplasty or argon laser trabeculoplasty
Surgery - trabeculectomy to form a new outflow channel
What are the risk factors for acute angle closure glaucoma?
Increasing age
Female
East Asian ethnicity
Hypermetropia
Mydriatic drugs
What types of medications can precipitate acute angle-closure glaucoma?
Adrenergic medications e.g noradrenaline
Anticholingeric medications e.g oxybutynin and solifenacin
Tricyclic antidepressants e.g amitriptyline
