Term
| Describe aqueous humor production |
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Definition
| continuously produced in the ciliary body; moves from the posterior chamber to the anterior chamber and out of the eye through the trabecular meshwork-->Schlem's canal-->blood |
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Term
| Describe open angle glaucoma |
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Definition
| there is a histological change in the trabecular meshwork that slows the outflow of aqueous humor-->increases the amount of aqueous humor in the eye -->increases intraocular pressure |
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Term
| what can be done to treat open angle glaucoma? |
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Definition
| decrease aqueous humor production (turn off tap); increase aqueous humor production (unclog drain) |
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Term
| How can the tap be turned off (for aqueous humor production)? |
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Definition
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Term
| what type of autonomic drugs will decrease aqueous humor production? |
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Definition
| alpha2 agonist; beta antagonist |
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Term
| What beta blockers are used for open angle glaucoma? |
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Definition
they turn the tap off
non-selective: timolol, carteolol, levobunolol
beta1 selective: betaxolol |
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Term
| what alpha2 agonists are used for open angle glaucoma? |
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Definition
they turn the tap off
brimonidine; apraclonidine |
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Term
| What is the MOA for beta antagonists/alpha2 agonists in open angle glaucoma? |
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Definition
| decrease aqueous humor production by the ciliary body--> decrease IOP |
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Term
| what effect does the muscarinic receptor activation have in the eye? |
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Definition
| contract the ciliary m.-->lens rounds out; constrict the pupil |
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Term
| How can cholinomimetics (i.e. pilocarpine) treat OAG? |
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Definition
-they unclog the drain
pilocarpine-->contracts ciliary m. --> pulls on the trabecular meshwork--> opens "holes" -->increase outflow of aqueous humor |
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Term
| What muscarinic agonists can be used for OAG? |
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Definition
unclog the drain
pilocarpine, carbachol |
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Term
| which reversible AChE inhibitor is used to OAG? |
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Definition
unclog the drain
physostigmine (crosses the BBB--it's pyridostigmine that's used for myasthenia gravis) |
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Term
| which irreversible AChE inhibitor is used for OAG? |
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Definition
unclog the drain
echothiophate (last choice drug) |
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Term
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Definition
| increases uveoscleral and trabecular aqueous humor outflow |
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Term
Treatment summary
brimonidine; betaxolol |
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Definition
| decrease production; no blurred vision |
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Term
treatment summary
pilocarpine |
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Definition
increases outflow
blurred vision |
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Term
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Definition
increases outflow
no blurred vision; less effective |
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Term
| what's the first choice treatment for OAG? |
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Definition
beta blockers
alternative add-ons are epi, alpha agonists, and cholinomimetics |
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Term
| what's marijuanas relationship to OAG? |
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Definition
loweres IOP by about 24%; cannabinoid receptors found on the retina, ciliary body, and iris
but MOA only 3-3.5 hours |
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Term
| narrow angle glaucoma definition |
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Definition
| there is a structural defect in the eye that causes a narrow angle between the iris and the cornea |
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Term
| attacks of narrow angle glaucoma usually occur when the pupil is ___? |
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Definition
| dilated-->pupillary block-->iris root obstructs the outflow of aqueous humor through the trabecular network |
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Term
| aqueous humor production is normally? |
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Definition
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Term
| outflow through the trabecular meshwork is normally? |
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Definition
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Term
| what would happen if outflow through the trabecular is blocked? |
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Definition
| attack of narrow angle glaucoma; IOP increases from 15 to 40-60 mmHg; this can cause blindness |
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Term
| how can pilocarpine treat NAG? |
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Definition
contract iris sphincter smooth m.--> induce miosis-->pulls iris away from the trabecular meshwork -->increases outflow of aqueous humor --> decreaes IOP
(in OAG it contracts ciliary muscle which opens the trabecular meshwork) |
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Term
| Is pilocarpine used chronically for the treatment of NAG? |
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Definition
| No-it's used to decrease pressure in an acute attack; do iridectomy (hole in iris) |
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