Question | Answer |
Glaucoma | refers to a group of diseases characterized by visual field loss secondary to optic nerve damage |
Primary open-angle Glaucome | - most common form of glaucoma & leading cause of blindness
- characterized by progressive optic nerve damage w/ eventual impairment of vision
- Painless & symptoms do not arise till optic nerve damage has been produced |
Risk factors for OAG | - Elevated IOP
- African or south american
- family history of POAG
- advanging age
** elevated IOP most important** |
Most important form of prevention of blindness from OAG? | - screening! |
Managements of OAG | - directed at reducing elevated IOP |
Angle-Closure Glaucome | - displacement of iris such that it covers trabecular mesh-work, preventing exit of aqueous humor from the anterior chamber \
- IOP raises rapidly to dangerous levels- VERY PAINFUL
- no tx leads to irreversible vision loss in 1-2 days |
TX OF ACG | - drug therapy followed by corrective surgery
- once IOP is decreased, laser iridotomy and iridectomy may be performed |
BETA BLOCKERS | - first line drugs for glaucoma
- lowers IOP by decreasing production of aqueous humor
- used primarily for OPEN-ANGLE GLAUCOMA |
Beta Blockers Adverse Effects | - Local effects (burning, conjuctivitis, blurred vision, photophobia)
- Heart and lung effects : produce bradycardia & AV block (monitor pulse rate) |
Beta blocker contradictions | - not to be used in patients with AV Block, sinus bradycardia, cardiogenic shock
** CAUTION IN PATIENTS W/ HEART FAILURE**
- causes bronchostriction
- betaxolol only apprived BB for patients w/ asthma & COPD |
Prostaglandin analogs:
LANTAPROST | - applied topically to lower IOP in patients w/ OPEN ANGLE GLAUCOMA & OCULAR HYPERTENSION |
Lantaprost MOA | - lowers IOP by facilitating aqueous humor outflow in part by relaxing the ciliary muscle |
Lantaprost SE: | - harmless BROWN pigmentation of the iris
- may also increase length, thickness, and pigment of eyelashes
- blurred vision, buring/stinging, conjuctival hyperemia, punctate keratopathy. |
Other Prostaglanding analogs | - travopost, bimatoprost, taflupost reduced IOP by increasing aqueous humor outflow
- more effecting in African Americans
- Bimatoprost (Latisse) helps grow longer & thicker eyelashes
- common SE: ocular hyperemia (engorgement of ocular blood vessels) |
Alpha2-adrenergic agonists:
Brimonidine | - LONG term reduction of elevated IOP in pt's w/ OPEN ANGULAR/ ocular hypertension
MECH OF ACTION: lowers IOP by reducing aqueous humor production, and increasing outflow
- may delay optic nerve damage |
Brimonidine side effects: | - dry mouth, ocular hyperemia, burning/stinging, foreign body sensation. ocular itching
- CAN CROSS B-B-B and cause drowsiness, fatigue, hypertension
** absorb into contact lenses, advise pt to administer 15 minutes before placing lenses |
Alpha2-adrenergic agonists:
Apraclonidine | - SHORT TERM THERAPY
- lowers IOP by reducing aqueous humor production and increasing outflow (same as Brimonidine)
- For OAG pt's who did not respond well to other drugs |
Alpha2-adrenergic agonists:
Apraclonidine side effects: | - headache, dry mouth and nose, altered taste, etc
DOES NOT CROSS B-B-B = NO HYPOTENSION |
Pilocarpine: direct acting muscarinic agonist | - stimulates cholinergic receptors producing (1) miosis (2) contraction of the ciliary muscle- IOP lowered indirectly
- Patients with OAG IOP is reduced due to tension generated by contracting ciliary muscle promotes widening within the trabecular mesh |
Pilocarpine: direct acting muscarinic agonist effect on ACG | - contraction of iris sphincter pulls iris away from the pores of the trabecular mesh, removing impediment to aqueous humor flow |
Pilocarpine: direct acting muscarinic agonist THERAPEUTIC USES: | - 2nd line drug for OAG & used in emergencies for Acute-angle-closure glaucoma |
Pilocarpine: direct acting muscarinic agonist ADVERSE EFFECTS: | - may need corrective lens for near vision, retinal detachment, decrease visual acuity.
Systemic: bradycardia, bronchospasm, hypersalivation, diarrhea,
**CAUTION USE W/ ASTHMA & bradycardia**
- toxicity reversal: atropine (muscarinic antagonist) |
Echothiophate: cholinesterase inhibitor | - long duration of action
- inhibits breakdown of Acetylcholine, promoting accumulation of ACHE at muscarinic receptors
- Indicated for POAG |
Echothiophate: cholinesterase inhibitor adverse effects: | - myopia and excessive constriction
***CATARACTS*** |
Carbonoc Anhydrase inhibitors: topical
Dorzolamide | - reduces IOP in patietns w/ OAG
- lower IOP by decreasing production of aqueous humor |
Carbonoc Anhydrase inhibitors: topical
Dorzolamide SIDE EFFECTS: | - BITTER TASTE & ocular stinging |
Carbonoc Anhydrase inhibitors: systemic
ACETAZOLAMIDE & METHOZOLAMIDE | - lower IOP by decreasing production of aq. humor.
- for long term tx of OAG
ADVERSE EFFECTS: CNS ( malaise, anorexia, fatigue) , MALAISE may be intense, GI disturbances
- HARMFUL TO PETS AND PREGNANCY |
Cycloplegics | - paralyze ciliary muscles |
mydriatics | - dilate the pupil |
cycloplegics and mydriatics | - use to facilitate dx and surgery |