Opthalmology Flashcards
(11 cards)
What is Primary Open Angle Glaucoma?
Decreased flow of aqueous humour through the trabecular meshwork due to a gradual increase in resistance.
Slow Gradual decline in visual changes.
What is the vision loss like in primary open angle glaucoma?
Glaucoma affects the peripheral vision first, resulting in gradual loss of peripheral vision loss (tunnel vision)
What are the two ways of measuring intraocular pressure?
- Non-contact tonometry
Less accurate but good for general screening purposes. - Goldmann applanation tonometry (Gold-standard)
Involves a device mounted on a slit lamp that makes contact with the cornea and applies various pressures.
What is used to measure the angle between the iris and cornea?
Gonioscopy
What do prostoglandin analogues do in the treatment of Glaucoma?
Increase uveoscleral outflow.
What do beta-blockers (timolol) do in the treatment of Glaucoma?
Reduce the production of aqueous humour.
(same as carbonic anhydrase inhibitors e.g. dorzolamide)
What causes Acute Angle Closure Glaucoma?
Occurs when the iris bulges forwards and seals off the trabecular meshwork from the anterior chamber, preventing the drainage of aqueous humour.
MEDICAL EMERGENCY
How does a patient with Acute Angle Closure Glaucoma present?
- Severely painful red eye.
- Blurred Vision
- Halos around lights
- Associated headache, nausea and vomiting.
What immediate treatment options are there for Acute-Angle Closure Glaucoma?
- Pilocarpine eye drops (causing pupillary constriction)
- Acetazolamide (carbonic Anhydrase inhibitor which decreases the production of Aqueous humour)
What is the definitive treatment option for AAC Glaucoma?
Laser iridotomy. It involves making a hole in the iris with a laser which allows aqueous humour to flow directly into anterior chamber from the posterior chamber.
which relieves the pressure causing the iris to occlude the trabecular meshwork.
