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29 Cards in this Set
- Front
- Back
What are the types of glaucoma?
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Open angle--most common
Narrow angle |
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What is open angle glaucoma (OAG)?
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Histological change in trabecular meshwork that slows outflow of aqueous humor --> increases amount of aqueous humor in eye --> increases introcular pressure
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What can be done to treat OAG?
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Decrease aqueous humor production (turn off tap) and increase aqueous humor outflow (unclog the drain)
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What non-selective beta blockers are used for OAG?
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Timolol
Carteolol Levobunolol |
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What beta 1 selective blockers used for OAG?
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Betaxolol
Levobetaxolol |
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What is the MOA of beta blockers in OAG?
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Beta blockers --> decrease aqueous humor production by the ciliary body --> decreases IOP (20-30%)
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What direct acting adrenomimetics are used for OAG?
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Epinephrine--A and B
Dipivefrin --A and B Brimonidine--A2 Apraclonidine--A2 |
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How does Brimonidine work on OAG?
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A2 on ciliary epithelium --> decrease aqueous humor production --> decrease intraocular pressure (IOP)
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How does EPI work on OAG?
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EPI --> B2 on endothelial cells of trabecular meshwork --> increases outflow of aqueous humor --> decrease IOP
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What cholinomimetics used for glaucoma?
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Muscarinic agonists--Pilocarpine and Carbachol
Reversible AChE inhibitors--Physostigmine Irreversible AChE inhibitors--Echothiophate |
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How does a cholinomimetic work on OAG?
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Pilocarpine --> contracts ciliary muscle --> pulls on trabecular meshwork --> opens "holes" --> increases ouflow of aqueous humor
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Treatment of OAG with Epinephrine...
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Increases outflow and decreases production --> no blurred vision
Less effective |
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Treatment of OAG with Brimonidine and Betaxolol...
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Decreased production --> no blurred vision
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Treatment of OAG with Pilocarpine...
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Increased outflow --> blurred vision (affects ciliary muscle)
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Why do you get blurred vision with Pilocarpine and not betaxolol?
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Pilocarpine activates M receptors on the ciliary muscle
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What is the first choice treatment in OAG?
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Beta blockers
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What are the alternative tx choices for OAG?
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Epinephrine
Cholinomimetics: Pilocarpine (first) Carbachol Physostigmine Echothiophate (last) |
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What is the advantage of using a beta blocker (betaxolol) over pilocarpine for treating OAG?
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Less side effects and no effect on the lens (doesnt move ciliary muscle)
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What topical carbonic anhyddrase inhibitors are used for OAG?
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Brinzolamide
Dorzolamide |
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What prostaglandins are used in OAG?
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Latanoprost
Travoprost Bimatoprost |
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How does marijuana affect glaucoma?
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Lowers IOP by about 24%
Does not work topically MOA unknown Cannabinoid receptors found--retina, ciliary body, and iris |
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What is the potential problem with marijuana and glaucoma?
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DOA only 3-3.5 hours and the goal is to maintain a continuous lowering of IOP
dont know if interferes with other glaucoma meds |
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What is narrow angle glaucoma (NAG)?
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There is a structural defect in the eye that causes a narrow angle between the iris and the cornea.
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When do attacks of NAG occur?
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When the pupil is dilated --> obstructs the outflow of aqueous humor through the trabecular meshwork
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What would happen if outflow through the trabecular is blocked?
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Attack of NAG --> IOP can increase from 15 mmHG to 40-60 mm Hg --> can cause blindness
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How does Pilocarpine treat NAG?
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Pilocarpine --> contract the iris sphincter smooth muscle --> induce miosis --> pulls the iris away from the trabecular meshwork --> increase outflow of aqueous humor --> decrease IOP
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Will pilocarpine be used chronically for the treatment of NAG?
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No, it is used to reduce pressure during an acute attack. Chronic treatment or cure is iridectomy.
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What are the alternative tx for NAG attaks?
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Carbachol
Physostigmine Echothiophate Decreasing aqueous humor production with other drugs (beta blockers) may be helpful but takes too long |
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How does cholinomimetics work on NAG?
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Pilocarpine --> NAG --> contract iris sphincter muscle --> move iris out of the way --> increase outflow
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