Glaucoma Flashcards
(33 cards)
What is glaucoma?
It is an eye condition that causes progressive degeneration of the optic nerve (results in irreversible blindness)
Progressive narrowing field of view
What is the etiology of glaucoma?
Caused by increased IOP due to either reduced drainage or increased production of vitreous humour
What are the four main types of glaucoma?
- Primary Open-Angle Glaucoma (most common presentation)
- Angle-Closure Glaucoma (acute situation, refer)
- Secondary Glaucoma
- Normal-Pressure Glaucoma
What are some specifics of primary open-angle glaucoma?
Increased production or reduced drainage of vitreous humour causes increased IOP, which damages the optic nerve
Develops gradually and painlessly (only diagnosed via eye exam)
Accounts for 90% of glaucoma cases
What are some risk factors associated with open-angle glaucoma?
- Elevated intraocular pressure (only modifiable risk factor)
- Increasing age
- Family history
- African ancestry
- HTN, DM, Migraines
- Corticosteroid use (systemic>opthal>inhaled/intranasal)
- See slide 8
What are the specifics of angle-closure glaucoma?
Much less common, but is considered to be a medical emergency
Iris bulges forward to block the drainage angle formed by cornea and iris (aqueous fluid cannot drain, and IOP shoots through the roof) (see slide 10)
What are some treatment options for angle-closure glaucoma?
Eye drops/oral medications acutely lower IOP
ASAP laser surgery to widen drainage angle
What are some signs and symptoms associated with angle-closure glaucoma?
- Severe eye pain
- Eye redness
- Blurred vision, halos around lights
- Nausea and vomiting
- Headache
What are some risk factors for developing angle-closure glaucoma?
- Increasing age
- Female
- Positive personal or family history
- Asian or Inuit descent
- Hyperopia
- Proliferative diabetic retinopathy
- Topiramate use
What is the association between anticholinergic drugs and glaucoma?
This is only relevant for patients with acute angle-closure glaucoma
Avoid 1st gen antihistamines, antispasmodic, TCAs, and decongestants
What are some goals of therapy for glaucoma?
- Prevent, halt, or slow vision loss
- Preserve the structure and function of the optic nerve
- Improve or maintain functional vision
- For acute angle closure (eliminate pain and other associated)
What are some treatment options for open-angle glaucoma?
Focuses on reducing intraocular pressure (IOP)
- Eye drops
- Laser surgery
- Eye surgery
How are IOP targets set for open-angle glaucoma treatment?
Target IOP is based on the following:
- The extent of glaucomatous damage (amount of disc cupping and vision loss)
- The estimated IOPs associated with that damage
- The burden of therapy to achieve the desired IOP
- IOP targets are lowered even further if damage to optic disc or visual field progresses
What are some topical agents for open-angle glaucoma?
- PG analogues
- Beta-blockers
- a2-agonists
- Carbonic anhydrase inhibitors
- Cholinergic agonists
What are some examples of PG analogues used in open-angle glaucoma?
Latanaprost, travaprost, bimatoprost
What is the MOA of PG analogues for open-angle glaucoma?
Increase aqueous humour outflow
First-line option (most effective at lowering IOP by 30%)
How are PG analogues for open-angle glaucoma tolerated?
Generally tolerated well, few systemic adverse effects
Adverse effects: Mild conjunctival hyperemia, thicker
eyelashes, and possible iris darkening (rare)
What are some examples of topical beta-blockers used to treat open-angle glaucoma?
Betaxolol, levobunol, timolol
What is the MOA of beta-blocker drops in glaucoma treatment?
Reduce production of aqueous humour
What are some contraindications and caution for beta-blocker drop use in open-angle glaucoma patients?
Avoid in patients with syncope or bradycardia
Use with caution in asthma/COPD
- Avoid in severe disease
- Monitor for worsening of these conditions!
- Betaxolol is cardio (β1) selective
What are some examples of alpha-2 agonists used in open-angle glaucoma treatment?
Brimonidine (2nd line therapy, adjunct)
What is the MOA of alpha-2 agonists in open-angle glaucoma?
Decrease production and increase outflow of aqueous humour
What are some adverse effects associated with a2-agonists in open-angle glaucoma?
Higher rate of conjunctival hyperemia and ocular
allergy than prostaglandins or beta-blockers
What are some examples of topical carbonic anhydrase inhibitors used in open-angle glaucoma?
Dorzolamide and brinzolamide (2nd line, used if pt cannot use topical beta blockers)
