Glaucoma Flashcards
What is intraocular pressure? (IOP)
Balance of between rate of formation of aqueous humor and amount of resistance to its outflow
What is IOP considered?
The only modifiable risk factor of glaucoma
What percentage of cases of primary glaucoma is open angle?
90-95%
Is primary open angle glaucoma quick or slow progressing?
Slow
What percentage of cases of primary glaucoma is angle closure?
10%
Is angle closure glaucoma an emergency?
YES
What is the MC agent used in glaucoma?
Beta blockers
What to beta blockers do for glaucoma?
Affects on beta receptors in ciliary processes which leads to reduction of aqueous humor production
How do you reduce systemic side effects of beta blockers?
Using punctal occlusion -> holding the lacrimal duct for 3-5 minutes
What line of tx are beta blockers for glaucoma?
First line agent
How effective is Betaxolol as a BB for glaucoma?
Doesnt lower IOP as much as other products
What is the gold standard of tx for glaucoma?
Timolol solution
Is Timolol solution selective or non-selective?
Non-selective
What kind of solution is Timolol?
Gel-forming
How often does a pt use Timolol?
Once a day
What is the benefit of adrenergic agents?
They act on alpha and beta receptors
What affect do adrenergic agents have on alpha receptors?
Decrease aqueous humor production
What affect do adrenergic agents have on beta receptors?
Increase in outflow
What adrenergic agents are commonly used?
Epinephrine
Dipivefrin
What are some SEs of adrenergic agents?
Systemic:
- palpations
- tachycardia
- headache
- anxiety
- increased sweating
What is dipivefrin?
A prodrug of epinephrine
When is dipivefrin shown to be effective?
When in combo w/ a non-selective beta blocker
more pronounced IOP decrease
MOA of selective alpha 2 agonists
Decreases aqueous humor production
Increases uveoscleral outflow
Two selective alpha 2 agonists
Apraclonidine
Brimonidine
When are select alpha 2 agonists used?
W/ other agents if used at all
Issue with apraclonidine
Tachyphylaxis develops rapidly
When can you use brimonidine alone?
With pts who are intolerant to beta blockers
What do cholinergics do to the eye?
Stimulation of sphincter pupillae
and causes miosis
What happens when cholinergics work on the eye?
Pulls open the meshwork and increases outflow
What does Pilocarpine do?
Reduces IOP by 20-30%
What are two cholinergic agents?
Pilocarpine
Carbachol
What is a different name for Pilocarpine and how is it released?
Ocusert
Slow-release
What is the MOA of cholinergic anticholinesterase agents?
Binds to enzyme which breaks down endogenous acetylcholine
Cholinesterase inhibitor
When do you use anticholinesterases?
When pts are unresponsive or intolerant of other therapies
What is the effect of carbonic anhydrase inhbitors (CAIs)
Inhibit carbonic anhydrase in ciliary body to decrease aqueous formation by 40-60%
CAI agents
Dorzolamide and Brinzolamide
Acetazolamide
How are dorzolamide and brinzolamide given and how large is the effect?
Topically
Reduced IOP and 15-26%
How is acetazolamide given and how large is its effect?
Orally
Reduce IOP by 25-40%
What is an issue with acetazolamide?
It has a higher incidence of SEs
What do prostaglandin F2-alpha analogues do?
Increase uveoscleral outflow of aqueous humor
How many side effects do prostaglandin F2 meds have and what are they?
Fewer than Timolol
Iris pigmentation
Eyelash thickening
How efficacious are prostaglandin F2 meds?
Decrease IOP similarly to beta blockers if not MORE
Prostaglandin F2 example and dosing
Latanoprost solution 0.05%
Dose q24 hours
Tx of angle-closure glaucoma
Go to ER
Iridectomy = definitive tx
What are the 3 meds of choice for glaucoma
Beta blockers
Prostaglandin F2-alpha analogues
Carbonic Anhydrase Inhibiton