Opthomology Drugs Flashcards
open angle glaucoma
angle between iris and cornea is 45 degrees or more. you need to give medication to lower the pressure
narrow angle glaucoma
space between the cornea and iris is less than 20 degrees. you have to use a laser to open the iris to allow for release of pressure
pupil action under sympathetic innervation
Norepi is the neurotransmitter. alpha 1a AR subtype is in the iris dilator muscle. Alpha 1 b causes iris arteriolar contraction. superior palpebral muscle of muller lifts eyelid, ciliary epithelium does aqueous production, increases outflow of aqueous
pupil action under parasymp innervation
contraction of the pupils. uses ACh as neurotransmitter. muscarinic M3 receptors in ciliary body and iris contract the iris sphincter and circular fibers of ciliary muscle. contract fibers of ciliary body opening trabecular meshwork
in order to read you must have
accommodation: thickening of lens moving focal point closer to the eye. convergence of the eyes. miosis of the pupils. start to lose this ability at age 45
presynaptic vs. postsynaptic lesions
presynaptic are serious, can come from tumor, MS, vascular accident. postsynaptic are benign: Aidies syndrome, pharmacologic blockade
phenylephrine
mimics NE alpha 1 (dilates eye). sympathetic agonist
parasympathetic muscarinic agonist
pilocarpine, echothiopate, physostigmine
cocaine
prevents reuptake of NE. indirect sympathetic system agonist
hydroxyamphetamine (paredrine)
releases NE. indirect sympathetic agonist
timolol and betaxolol
beta blockers. timo is nonspecific, betaxo is B1 specific
prostaglandin analogs
increase uveoscleral outflow
carbonic anhydrase inhibitors
reduce aqueous production
horner’s syndrome
sympathetic paresis. miosis, ptosis, anhidrosis. preganglionic: CNS lesions, lung tumors, thoracic aortic aneurysms. Postganglionic: migraine equivalent
cocaine in horner’s syndrome
if sympathetic system is dysfunctional, pupil will not dilate
separating 1st or 2nd order from 3rd order horner’s
if third order neuron intact but not stimulated then paredrine will cause pupillary dilation (bad). if pupil does not respont to paredrine then 3rd order lesion. (good)
parasympathetic paresis
loss of parasympathetic function leads to pupillary dilation. ptosis and loss of eye movement. worst headache of life could mean an aneurysm.
Adie’s syndrome
parasympathetic dysfunction leading to large pupil. damage to ciliary ganglion. accommodation is present
how to separate adie’s syndrome from aneurysm
denervation hypersensitivity. use small dose of methacholine or pilocarpine. pupillary constriction will happen if Adie’s syndrome
pharmacologic blockade
bad headache, pupil not responding to light or accommodation. give low dose of muscarinic agonist. should be no pupil change. give high dose. if still no pupil change, then pharm blockade.
side effects of beta blockers
bradycardia, hypotension, syncope, palpitation, bronchospasm, mental confusion, depression, fatigue, hyperkalemia
adrenergic side effects
extrasystoles, palpitations, hypertenstion, trembling, paleness, sweating
cholinergic side effects
bronchospasm, salvation, nausea, vomiting, diarrhea, ab pain, lacrimation, sweating
anticholinergic effects
ataxia, nystagmus, restlesness, mental confusion, aggressive behavior, insomnia, photophobia, urinary retention
what 3 things can cause pupil to respond to accommodation but not light?
adie’s syndrome (young females with no patellar reflex)
parinaud’s syndrome (young kids with midbrain tumor (pineal))
argyll-robertson (tertiary syphillis)
