Podcast
Questions and Answers
Which of these is the most common form of glaucoma in the United States?
Which of these is the most common form of glaucoma in the United States?
What is the primary method of treatment for open-angle glaucoma?
What is the primary method of treatment for open-angle glaucoma?
Which of the following is NOT a first-line drug for the treatment of glaucoma?
Which of the following is NOT a first-line drug for the treatment of glaucoma?
Which type of drug lowers IOP by facilitating aqueous humor outflow?
Which type of drug lowers IOP by facilitating aqueous humor outflow?
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Which of the following is a common side effect of beta-adrenergic blocking agents used for glaucoma?
Which of the following is a common side effect of beta-adrenergic blocking agents used for glaucoma?
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Which of the following drugs is used for short-term therapy of glaucoma?
Which of the following drugs is used for short-term therapy of glaucoma?
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What is the mechanism of action of echothiophate (phospholine iodide)?
What is the mechanism of action of echothiophate (phospholine iodide)?
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Which of the following is a common side effect of topical carbonic anhydrase inhibitors?
Which of the following is a common side effect of topical carbonic anhydrase inhibitors?
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What is the primary function of cycloplegics?
What is the primary function of cycloplegics?
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Which of the following is a common adverse effect of mydriatics?
Which of the following is a common adverse effect of mydriatics?
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Which of the following is NOT a type of treatment for allergic conjunctivitis?
Which of the following is NOT a type of treatment for allergic conjunctivitis?
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What is the primary characteristic of wet (neovascular) age-related macular degeneration?
What is the primary characteristic of wet (neovascular) age-related macular degeneration?
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Which of the following is NOT a treatment option for wet AMD?
Which of the following is NOT a treatment option for wet AMD?
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Which of the following is a topical cyclosporine ophthalmic emulsion used to suppress the immune response and promote tear production?
Which of the following is a topical cyclosporine ophthalmic emulsion used to suppress the immune response and promote tear production?
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Which of the following is NOT an ocular decongestant?
Which of the following is NOT an ocular decongestant?
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What is the primary function of fluorescein dye in ophthalmology?
What is the primary function of fluorescein dye in ophthalmology?
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Flashcards
Glaucoma
Glaucoma
A condition causing visual field loss due to optic nerve damage, often linked to high intraocular pressure (IOP).
Aqueous Humor
Aqueous Humor
Fluid produced in the ciliary body that circulates in the eye and maintains intraocular pressure.
Primary Open-Angle Glaucoma (POAG)
Primary Open-Angle Glaucoma (POAG)
The most common form of glaucoma, characterized by gradual optic nerve damage with no early symptoms.
Angle-Closure Glaucoma
Angle-Closure Glaucoma
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Beta-Adrenergic Blocking Agents
Beta-Adrenergic Blocking Agents
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Prostaglandin Analogs
Prostaglandin Analogs
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Alpha2-Adrenergic Agonists
Alpha2-Adrenergic Agonists
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Pilocarpine
Pilocarpine
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Age-Related Macular Degeneration (AMD)
Age-Related Macular Degeneration (AMD)
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Dry AMD
Dry AMD
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Wet AMD
Wet AMD
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Cholinesterase Inhibitor
Cholinesterase Inhibitor
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Ocular Decongestants
Ocular Decongestants
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Cycloplegics
Cycloplegics
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Study Notes
Glaucoma
- Leading cause of preventable blindness in the US
- Only 50% of 4 million Americans with glaucoma are diagnosed
- 90% could have saved their sight with timely treatment.
- Types: Primary open-angle glaucoma (POAG), Acute angle-closure glaucoma.
- Optic nerve damage resulting in visual field loss.
Aqueous Humor
- Produced in the ciliary body.
- Secreted into the posterior chamber of the eye.
- Circulates around the iris to the anterior chamber.
- Exits the anterior chamber via the trabecular meshwork and canal of Schlemm.
Primary Open-Angle Glaucoma (POAG)
- Most common type in the US
- Progressive optic nerve damage leads to vision impairment.
- Symptoms often absent until significant nerve damage occurs.
- Treatment focuses on reducing elevated intraocular pressure (IOP).
- Primarily treated with chronic drug therapy.
Drug Therapy for Glaucoma
- Drugs lower IOP by facilitating aqueous humor outflow and reducing its production.
- Topical administration preferred; systemic effects are uncommon.
- Combination therapy generally more effective than single-drug (monotherapy).
- Surgical interventions, like laser trabeculoplasty or trabeculectomy, may be necessary if drugs are ineffective.
- First-line drugs include beta-adrenergic blocking agents (like timolol), alpha2-adrenergic agonists (like brimonidine), and prostaglandin analogs (like latanoprost).
- Second-line drugs are cholinergic agonists, carbonic anhydrase inhibitors, beta blockers, alpha2 agonists, and prostaglandin analogs.
Angle-Closure Glaucoma
- Also known as narrow-angle glaucoma
- Sudden blockage of aqueous humor exit by iris displacement.
- Causes extreme pain and rapid vision loss (1-2 days).
- Much less common than POAG.
- Treatment: Drug therapy, corrective surgery (laser iridotomy or iridectomy).
Beta-Adrenergic Blocking Agents
- Approved for glaucoma: Betaxolol, carteolol, levobunolol, metipranolol, timolol
- Lower IOP by reducing aqueous humor production.
- Primarily for open-angle glaucoma.
- Initial and maintenance therapy.
- Potential side effects: Local (usually minimal), Systemic (heart and lung issues with significant absorption - bradycardia, bronchospasm).
- Cardioselective agents (betaxolol) recommended for asthmatics.
Prostaglandin Analogs
- Examples: Latanoprost, travoprost, bimatoprost, tafluprost
- Lower IOP by increasing aqueous humor outflow.
- As effective as beta blockers, with fewer side effects.
- May cause harmless iris pigmentation changes.
Alpha2-Adrenergic Agonists
- Apraclonidine: Short-term therapy for IOP reduction.
- Brimonidine (Alphagan): First-line long-term therapy for IOP reduction.
- Combigan (0.2% brimonidine and 0.5% timolol) is a combined drug.
- Side effects comparable to separate application of timolol and brimonidine.
Pilocarpine
- Cholinergic agonist, causing miosis and ciliary muscle contraction.
- Second-line drug for open-angle glaucoma; emergency treatment for acute angle-closure glaucoma.
- Potential side effects: Retinal detachment, decreased visual acuity, local irritation and eye pain.
Cholinesterase Inhibitor
- Echothiophate (phospholine iodide): Long-acting, inhibits ACh breakdown, promoting accumulation, leading to miosis, lens focusing, and IOP reduction.
- Not a first-line drug today.
- Potential side effects: Myopia, cataracts.
Carbonic Anhydrase Inhibitors (CAIs)
- Topical: Dorzolamide (Trusopt): Decreases aqueous humor production, well-tolerated with potential ocular stinging, bitter taste, allergic reaction in some cases.
- Systemic: Acetazolamide, methazolamide. High risk of adverse effects including nervous system effects, congenital abnormalities, acid-base imbalances, and electrolyte issues.
- Netarsudil: Rho-kinase inhibitor.
Cycloplegics and Mydriatics
- Cycloplegics paralyze ciliary muscles, mydriatics dilate pupils.
- Used for refraction measurement, eye exams, surgery, and uveitis treatment.
- Potential side effects: Blurred vision, photophobia, angle-closure glaucoma precipitation, systemic effects.
- Phenylephrine: Mydriatic (pupil dilation), does not cause cycloplegia.
Allergic Conjunctivitis
- Conjunctiva inflammation due to allergens (seasonal or perennial).
- Symptoms: Itching, burning, thin watery discharge.
- Treated with mast-cell stabilizers, H1-receptor antagonists, NSAIDs, corticosteroids (short-term), and ocular decongestants.
Age-Related Macular Degeneration (AMD)
- Progressive, painless disease causing central vision loss.
- Types: Dry (drusen) and Wet (neovascular - subretinal blood vessel growth).
- Stages: Early, Intermediate, Advanced.
Management of AMD
- Dry AMD: High doses of antioxidants and zinc.
- Wet AMD: Laser therapy, Photodynamic therapy (PDT), Angiogenesis inhibitors (Ranibizumab [Lucentis], Aflibercept [Eylea], Bevacizumab [Avastin]). PDT using verteporfin (Visudyne).
Additional Ophthalmic Drugs
- Demulcents (artificial tears): Isotonic solutions (polyvinyl alcohol, cellulose esters)
- Topical cyclosporine (Restasis) to suppress immune response for tear production.
- Ocular decongestants: Topical adrenergic agonists (Phenylephrine, naphazoline, oxymetazoline, tetrahydrozoline) to constrict dilated conjunctival blood vessels.
- Glucocorticoids (anti-inflammatory).
- Dyes (Fluorescein, rose bengal, lissamine green).
- Antivirals (Trifluridine, vidarabine, ganciclovir, idoxuridine).
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Description
This quiz covers critical information about glaucoma, including its types, causes, and the significance of timely treatment in preventing blindness. It also explores the role of aqueous humor in eye health and the primary drug therapies used to manage glaucoma effectively. Test your knowledge about these vital aspects of ocular health.
