Glaucoma Flashcards
is a group of eye conditions characterized by progressive damage of the optic nerve
Glaucoma
Second leading cause of blindness worldwide
Glaucoma
What causes glaucoma?
Mainly caused by persistent elevation of intraocular pressure (IOP)
What’s the normal IOP?
10-21 mmHg
What’s the diagnostic test for Glaucoma?
Tonometry
It is a diagnostic test that provides IOP by measuring the pressure needed to flatten the cornea
Tonometry
Precautions during tonometry
-Anesthetic eyedrops are instilled prior to procedure
- Patient should not hold breath during procedure as this may overestimate IOP
What are the Risk Factors of Glaucoma?
-African American Race
- Cardiovascular Disease
- Diabetes
- Family History of Glaucoma
- Migraine syndromes
- Nearsightedness (myopia)
- Older Age
- Previous eye trauma
- Prolonged use of topical or systemic corticosteroids
- Thin cornea
-Nutrient-filled fluid produces in the posterior chamber and drains in the anterior chamber
- Its volume directly influences the IOP
Aqueous Humor
-Mainly Water
- Maintains the shape of the eye
Vitreous Humor
Factors affecting AH drainage
-Angle created by the iris and cornea
- Integrity of the drainage system
The process of the normal pathway from production to drainage of aqueous humor
-Ciliary body produces AH
- AH passes through the pupil into the anterior chamber
- AH drains through the trabecular meshwork into Canal of Schlemm
What maintains a normal IOP?
An equal input to output volume of Aqueous Humor maintains a normal IOP.
Anterior Chamber Angle of Primary Open-Angle Glaucoma (POAG)
Open
Drainage System of Primary Open-Angle Glaucoma (POAG)
Obstructed
Onset of Primary Open-Angle Glaucoma (POAG)
Slow- onset beginning with one eye then may progress to the other if left untreated
Clinical Manifestations of Primary Open- Angle Glaucoma (POAG)
-Persistent dull eye pain in AM
- Tunnel Vision (Loss of peripheral vision)
Anterior Chamber Angle of Primary Closed-Angle Glaucoma (PCAG)
Closed/Narrowed
Drainage System of Primary Closed-Angle Glaucoma (PCAG)
Intact
Onset of Primary Closed- Angle Glaucoma (PCAG)
Rapid-Onset
Clinical Manifestations of Primary Closed-Angle Glaucoma
-Severe, rapid-onset eye pain
- Halos around lights (Presence of bright circles around light source)
- Blurred Vision
- Nausea/Vomiting
Medical Management of Primary Open-Angle Glaucoma (POAG)
Topical Medications (Eye Drops) – lowers IOP by increasing outflow of AH or decreasing production of AH
Timolol Drug
-First line drug of (POAG)
-Beta Blocker
- Action: Decrease AH production
- Side Effects: Hypotension, Bradycardia, Fatigue
Acetazolamide
-Carbonic Anhydrase Inhibitor
- Action: Decrease AH production
- Side Effects: Stinging/burning sensation in eyes
Pilocarpine
-Third Line
- Cholinergic Agent (Miotics)
Action: Increases draining of intraocular fluid through trabecular meshwork
-Side Effects: Difficulty seeing at night or in the dark pupil constriction
What are the drugs for Primary Open-Angle Glaucoma (POAG)
-Timolol
- Acetazolamide
- Pilocarpine
What’s the Emergency Medical Management of Primary Closed-Angle Glaucoma?
-Supine Position
- Acetazolamide IV/PO then Timolol eye drops
- Analgesics for pain and topical steroids to reduce inflammation
- Anti-emetics if with nausea/vomiting
Rationale of Supine Position in Emergency Medical Management
-improves lens position thereby removing pupil block
Rational to Administer Acetazolamide IV/PO then timolol eye drops
To lower IOP
After 1 hour of implementing emergency medical management
-Pilocarpine 2% or 4% - 2 doses spaced 15 minutes apart
-Mannitol IV or Glycerol IV if IOP is still elevated after 2nd dose of pilocarpine
Surgical Management of Primary Open-Angle Glaucoma
Laser Trabeculoplasty
Uses laser beam directed at the trabecular meshwork to alter its pores resulting to an increase in AH outflow
Laser Trabeculoplasty
Surgical Management of Primary Closed-Angle Glaucoma (PCAG)
-Laser Iridotomy
-Treatment of choice
-Surgical Iridectomy
-Alternative to laser iridotomy when cornea is extremely cloudy, or iris is too thick
Creation of an opening in the iris using a laser beam. The opening serves as passageway for the trapped AH in the posterior chamber
Laser Iridotomy
What to avoid in Glaucoma?
Atropine Sulfate
Bendryl
Cogentin
Rationale of Avoiding ABCs in Glaucoma
Promotes pupillary dilatation bringing the iris closer to the angle of outflow of aqueous humor