PRC Ocular Pharmacologist flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Aqueous humor production site

The ciliary epithelium of the ciliary body secretes aqueous humor via active transport involving Na+/K+-ATPase, carbonic anhydrase, and chloride channels, driven by osmotic gradients.

Trabecular outflow pathway

Pressure-dependent route accounting for approximately 80-90% of aqueous outflow; aqueous passes through trabecular meshwork into Schlemm canal and episcleral veins.

Uveoscleral outflow

Pressure-independent route accounting for roughly 10-20% of aqueous outflow; fluid passes through ciliary muscle interstitial spaces into suprachoroidal space and sclera.

Latanoprost mechanism

Prostaglandin F2α analog that increases uveoscleral outflow by remodeling extracellular matrix in ciliary muscle, lowering IOP with once-daily evening dosing.

Prostaglandin adverse effects

Iris hyperpigmentation, eyelash lengthening and darkening, periorbital skin darkening, and periorbital fat atrophy; effects are often irreversible and limit use in some patients.

Timolol contraindications

Nonselective beta-blocker contraindicated in asthma, COPD, sinus bradycardia, and second- or third-degree heart block; systemic absorption can cause bronchospasm and bradycardia.

Betaxolol selectivity

Cardioselective β1-blocker with less pulmonary risk than timolol; still requires caution in reactive airway disease and may cause stinging on instillation.

Brimonidine mechanism

Alpha-2 adrenergic agonist that reduces aqueous production and increases uveoscleral outflow; also provides neuroprotective effects in experimental models.

Brimonidine allergy rate

Follicular conjunctivitis and allergic blepharoconjunctivitis develop in roughly 10-15% of patients, often within 3-6 months, requiring discontinuation.

Dorzolamide action

Topical carbonic anhydrase II inhibitor that blocks bicarbonate formation in ciliary epithelium, reducing aqueous secretion and IOP by approximately 15-20%.

Acetazolamide systemic effects

Oral or IV carbonic anhydrase inhibitor causing metabolic acidosis, hypokalemia, paresthesias, and sulfonamide allergy cross-reactivity; used for acute IOP spikes.

Pilocarpine mechanism

Muscarinic agonist causing ciliary muscle contraction, which opens trabecular meshwork spaces and increases outflow; also causes miosis and induced myopia.

Pilocarpine contraindications

Contraindicated in acute iritis and anterior uveitis because it disrupts the blood-aqueous barrier; can cause paradoxical angle closure in susceptible eyes.

Netarsudil mechanism

Rho kinase inhibitor that relaxes trabecular meshwork and increases conventional outflow; also reduces episcleral venous pressure and aqueous production.

Netarsudil adverse effects

Conjunctival hyperemia, cornea verticillata, and reticular epithelial changes; verticillata is usually reversible and does not require discontinuation.

Mannitol use

Intravenous osmotic agent that draws water from vitreous and aqueous, rapidly lowering IOP in acute angle-closure crisis; monitor for fluid overload and electrolyte shifts.

Glycerol oral osmotic

Oral osmotic agent used for acute IOP elevation; contraindicated in diabetes because it is metabolized to glucose, and can cause nausea and hyperglycemia.

Preservative benzalkonium chloride

Common preservative in multi-dose drops that disrupts corneal epithelium and increases punctate keratopathy; avoid in severe dry eye and pre-operative patients.

Punctal occlusion technique

Applying pressure to the nasolacrimal duct for 1-2 minutes after instillation reduces systemic absorption and local side effects of topical ophthalmic medications.

Topical steroid potency

Potency varies by fluorination and esterification; prednisolone acetate 1% is standard, while difluprednate 0.05% is approximately twice as potent with higher IOP risk.

Steroid-induced IOP rise

Elevated IOP from topical steroids typically occurs after 2-6 weeks; steroid responders have greater risk, and monitoring is required during prolonged therapy.

Cycloplegic vs mydriatic

Cycloplegics (cyclopentolate, atropine) paralyze the ciliary muscle and dilate the pupil; mydriatics (phenylephrine) dilate only via α1 stimulation without cycloplegia.

Atropine duration

Long-acting antimuscarinic cycloplegic lasting 7-14 days; used for anterior uveitis and amblyopia therapy; risk of systemic anticholinergic effects in children.

Cyclopentolate use

Short-acting cycloplegic (duration 6-24 hours) used for refraction in children; can cause CNS excitation and should be avoided in neonates.

Tropicamide characteristics

Short-acting antimuscarinic with weak cycloplegia, primarily used for fundus examination; duration of mydriasis is 4-6 hours.

Phenylephrine 2.5% use

Alpha-1 agonist causing pupillary dilation without cycloplegia; 10% concentration risks significant hypertension and is avoided in infants and cardiac patients.

Fluorescein angiography dye

Sodium fluorescein 10-25% injected IV; excites at 465-490 nm and emits at 520-530 nm; adverse effects include nausea, urticaria, and rare anaphylaxis.

Indocyanine green properties

Dye with peak absorption near 805 nm and emission near 835 nm; better visualizes choroidal vasculature because it remains within larger choroidal vessels.

Anti-VEGF mechanism

Bevacizumab, ranibizumab, and aflibercept bind VEGF-A, reducing vascular permeability and neovascularization in AMD, diabetic retinopathy, and RVO.

Intravitreal injection risk

Endophthalmitis occurs in roughly 1 in 1,000-5,000 injections; aseptic technique, topical povidone-iodine, and post-injection monitoring are standard.

Topical antibiotic selection

Fluoroquinolones (moxifloxacin, gatifloxacin) offer broad gram-positive and gram-negative coverage; aminoglycosides carry corneal toxicity risk with prolonged use.

Natamycin indication

Topical polyene antifungal first-line for filamentous fungal keratitis; poor penetration and frequent dosing (every 1-2 hours initially) are required.