Ocular Flashcards
ACh
- PS system
- direct muscarinic agonist
- pupillary constriction, increased aq outflow
- tx. cataract sx and glaucoma
- SE: SLUDGE
Carbachol
- PS system
- direct muscarinic agonist
- pupillary constriction, increased aq outflow
- tx: cataract sx and glaucoma
- SE: SLUDGE
pilocarpine
- PS system
- direct muscarinic agonist
- pupillary constriction, increased aq outflow
- tx: catarcts and glaucoma
- SE: SLUDGE
**Pile on the sweat, salive and tears
atropine
antimuscarinic (PS system)
scopolamine
- antimuscarinic (PS)
tropicamide
antimuscarinic (PS system)
homatropine
antimuscarinic
cyclopentolate
antimuscarinic
antimuscarinics: mech and use
- pupillary dilation, paralysis of ciliary body
- use: cycloplegia for eye exams and to improve comfort during uveitis
SE of antimuscarinics/anticholinergics
- ataxia, nystagmus, restlessness, mental confusion, hallucinations, insomnia, photophobia, urinary retention
location of muscarinic receptors
- iris sphincter (contstrict pupil)
- circular fibers of ciliary muscle (constrict pupil)
- longitiudinal fibers of ciliary muscle (place tension on trabecular meshwork)
** contraction of ciliary muscle and opening of trabecular meshwork decreases IOP
edrophonium
- indirect agonist of nicotinic receptor
- destroys AChE
- used to dx Myasthenia Gravis
PS system
- Edinger-Westphal nucleus sends fibers in the oculomotor nerve (CN III) that synapse in the ciliary ganglia –> innervate pupillary constrictor mm
- preganglionic lesions (before ciliary ganglion) are bad
sympathetic system
- originates inteh hypothalamus –> fibers descend down the brainstem to thoracic spinal cord –> synapse –> 2nd order neurons exit SC and ascend with the paravertebral sympa chain –> synapse in the superior cervical ganglion –> 3rd order neurons run with the carotid plexus –> join opthalmic division of the CNV –> fibers pass with nasociliary nerve –> long ciliary nerve –> ciliary body and dilator muscles of iris
- preganglionic lesions (1st and 2nd order) are bad
location of sympa ocular receptors
- iris dilator muscle
- superior palpebral muscle of Muller (lifts eyelid)
- ciliary epi (facilitates aqueous production)
- smooth mm of ocular BV (vasodilation)
- trabecular meshwork (increase aq outflow)
phenylephrine
- sympa system
- mimic NE
- dilation of pupil
L-epinephrine
dilate pupil (sympa system)
dipivaly epinephrine
- prodrug of epi
- dilate pupil (sympa system)
Bromondine tartrate
- alpha 2 agonist (sympa system)
- suppress aq humor production
- contraindication: use with MAOI can caused fatigue/drowsiness
- ** know this one
clonidine
- alpha agonist (sympa system)
- lowers IOP via CNS effects
apraclonidine
alpha agonist (sympa system)
derivative of clonidine that doesnt cross BBB and has minimal effect on BP
cocaine
- inhibits reuptake of NE
- used to dx Horner’s syndrome (pupil fails to dilate)
hydroxyamphetamine (Paradrine)
- releases NE
- used to dx pre vs postganglionic lesion in Horner’s
- dilation = 3rd neuron must be intact and lesion lies within 1st or 2nd order neuron –> CNS lesion, apical lung tumor or thoracic aortic aneurysm
Dapiprazole
- reverses action of Tropicamide and Phenylephrine
- blockage of alpha-adrenergic receptors in smooth dilator muscle of iris
beta blockers
- Timolol, Betaxolol, Metipranolol
- suppress aq production
- tx: glaucoma
- SE: bardycardia, hypotension, syncope, palpitation, CHF, bronchospasm
- contraindications: CHF, asthma
Acetazolamide
- carbonic anhydrase inhibitor (oral)
- reduce production of aq via intereference with active transport of Na+
- tx: glaucoma
- but many SE (use topicals 1st)
ethoxzolamide and methazolamide
carbonic anhydrase inhibs (oral)
tx: glaucoma
but many SE
**Dorzolamide Hydrochloride
- carbonic anhydrase inhib (topical)
- decrease aq production via interference with active Na transport
- tx: glaucoma
- SE: allx to sulfonamides (red eyes and lid allx)
brinzolamide
- carbonic anhydrase inhib (topical)
- tx glaucoma
- SE: red eyes and lid allx
osmotic agents
- increase serum osmolarity and draw fluid from extravascular space into blood vessels
- tx glaucoma
- contraindicated in PTs with potential for heart failure due to increased intravascular volume
Latanoprost
- prostaglandin (eye drop)
- increase uveoscleral outflow
- tx: glaucoma
- contraindications: cystoid macular edema, herpes
- SE: growth of eyelashes and change in color of iris
bimatroprost, travoprost, unoprostone isopryl
- prostaglandins (eye drops)
- increase uveoscleral outflow
- tx glaucoma
- SE: eyelash growth, change of color of iris
SE of adrenergics (epi, phenylephrine)
- palpitiation, HTN, MI, trembling, paleness, sweating
1st line meds for glaucoma
- Timolol - beta blocker: decrease aq production
- Latanoprost- prostaglandin: increases uveoscleral outflow
- Brimondine - alpha 2 agonist: decrease aq production
- Dorzolamide HCl- carbonic anhydrase inhibitor: decreases aq production
how to dx horner’s syndrome
- cocaine –> no dilation confifrms Horner’s
- Paredrine –> dilation = lesion at 1st or 2nd order neuron (3rd order neuron is intact but not recieving stimulus)
how to dx Adie’s syndrome (tonic pupil)
- pilocarpine 1/8% or methacholine 2.5%
- pupil should constrict at this minimal dose because Ach will stimulate a chronically denervated nerve (due to hypersensitivity)
how to dx pharmacologic blockade
- pilocarpine 1% or methacholine 10% –> no constriction
- pupil should constrict under any circumstances (even aneurysm bc the ciliary body is ok)