Glaucoma Flashcards
What is the pathophysiology of Glaucoma?
Change in aqueous humor outflow (DEC’d elimination or INC’d production of aqueous humor) that results in INC’d intraocular pressure (IOP)
Will lead to optic nerve atrophy and consequentally progressive loss of vision
What are the different classifications of Glaucoma?
- Open-angle
- Angle-closure (Closed-angle glaucoma, CAG)
- Congenital
What is the pathophysiology of Open-angle glaucoma?
- Angle of the anterior chamber remains open in the eye
- Filtration of aqueous humor is gradually diminished because of the tissues of the angle (Results in DEC’d elimination of aqueous humor as it passes through the meshwork, thus elevating IOP)
What is the pathophysiology of Closed-angle glaucoma?
- Characterized by shallow anterior chamber and narrow angle
¦
- Filtration of aqueous humor is compromised (result of papillary blockage)
¦
- Aqueous humor accumulates and presses the lens forward
¦
- DEC drainage (possible complete bockage)
What is the pathophysiology of Congenital glaucoma?
Usually a result of defective development of structures in and around chamber of the eye (aqueous humor impairment)
Why is tonometry diagnostically important?
Tonometry helps SCREEN for IOP (Elevated IOP is diagnostic of glaucoma)
Why is Direct Ophthalmoscopy (slit-lamp examination) diagnostically important?
Direct Ophthalmoscopy is required to accurately evaluate the eye for changes in the optic nerve
What is a normal lab value for IOP? Critical values?
NML: 10-20 mmHg
Medical Emergency: >60 mmHg
What should be monitored for patients with Glaucoma? How often should patients be reassessed?
- INC’d IOP
- Medication adherence
- Intial re-assessment: every 2-4 weeks until optimal IOP
- Yealy examinations: 65+ Y/O (Part of routine eye examination)
What is the clincal presentation of glaucoma?
Develops slowly; may present only with minor symptoms (i.e. HA, mild eye pain)
What symptoms are specific to the clinical presentation of Acute CAG?
Blurred vision
Severe ocular pain
Possible N/V
What is the primary goal of treatment for Open-angle glaucoma?
DEC IOP (will reduce progression of vision loss)
What medications are available that may DEC rate of aqueous humor production? (identify general categories)
- Alpha-adrenergic agonist
- Beta-blockers
- Carbonic anhydrase inhibtors
What medications are available that may INC rate of outflow (drainage) of aqueous humor?
- Prostaglandins
- Alpha-adrenergic agonists
- Cholionergic agents
What are non-pharmacological therapies for open-angle glaucoma?
- Laser (1st LINE with medications)
- Surgical procedure
What Alpha-adrenergic agonists are available to DEC rate of aqueous humor production?
- Brimonidine (a2)
- Apraclondine (a2)
What beta-blockers (adrenergic anatagonists) are available to DEC rate of aqueous humor production?
- Timolol
- Carteolol
- Levobunolol
- Betaxolol
- Levobetaxolol
What carbonic anhydrase inhibitors are available to DEC rate of aqueous humor production?
- Dorzolamide
- Brinzolamide
- Acetazolamide
- Methizolamide
What prostaglandins are available to INC rate of outflow of aqueous humor?
- Lantoprost
- Bimatoprost
- Travoprost
- Unoprostone
What Alpha adrenergic agonists are available to INC rate of outflow of aqueous humor?
- Dipivefrin (non-specific)
- Epinephrine (non-specific)
What cholinergic agents are available to INC rate outflow of aqueous humor?
- Direct Agonist
- Pilocarpine
- Carbachol
- Cholinesterase inhibitor
- Echothiophate iodide
What is 1st LINE pharmacological treatment for open-angle glaucoma? Why?
Prostaglandins; well-tolerated and effective, may DEC IOP more than beta-blockers (traditionally 1st LINE, now considered 2nd LINE)
Why are Alpha agonists considered for pharmacological treatment of open-angle glaucoma?
Act similar to beta-blockers
T or F: Topical agents such as systemic carbonic anhydrase inhibitors may be used for pharmacological treatment of open-angle glaucoma.
F; these medications have been replaced by topical agents
Why are cholinergic agonists less utilized for treatment of open-angle glaucoma?
Ocular side effects have lead to decreased use of cholinergic agonists
What is best treatment for primary acute closed-angle glaucoma (CAG)?
Peripheral iridectomy which essentially “cures” primary CAG (used for chronic conditions); Long-term drug therapy is not commonly used
What empiric drug (classes) treatments may be adminsitered for Acute primary CAG? Why should the empiric treatment be given?
If delay of greater than 1 hour before patient can be seen ophthlamologist
- Beta-blocker
- Sympathomimetics
- Cholinargic agonists
- Systemic carbonic inhibitors
Which medications are available for treatment of acute CAG?
- Timolol (beta-blocker)
- Apraclonidine (Alpha-agonist)
- Pilocarpine (Cholinergic agonist)
- Acetazolamide (systemic, carbonic anhydrase inhibitors)
- Mannitol (systemic)
What are ADRs of beta-blockers?
- Breathing difficulties
- Bradycardia
- Hypotension
- CNS depression
What are ADRs of Prostaglandin anlogs?
- Darkened iris color
- Thickened eyelids and eye lashes
What are ADRs of Alpha-2 adrenergic agonists?
- Tachycardia
- Dry mouth
- CNS effects
What are ADRs of Nonspecific adrenergic agonists?
- Tachycardia
- INC’d BP
- Allergic responses
What are ADRs of Carbonic anhydrase inhibitors?
- Urinary frequency
- Nephrolithiasis
- Lethargy
- DEC’d appetite
What are ADRs of cholinergic agonist?
- Eye pain
- Burning
- Blurred vision
What are ADRs of Cholinesterase Inhibitors?
- Blurred vision
- Conjunctiva redness
- Paradoxial INC in IOP
What medication combinations with Timolol (beta-blocker) are available for treatment of glaucoma?
- Timolol-Dorzolamide (carbonic anhydrase inhibitors)
- Timolol-Brimonidine (a2)
What is the most important topic to educate a patient being treated for glaucoma?
MEDICATION ADHERENCE!
What drug interactions are associated with acetazolamide?
Aspirin (INC ASA levels)
Cyclosporine (INC cyclosporine levels)
Lithium (variable changes in lithium levels)
Phenytoin (INC risk of osteomalacia)
