L9 Flashcards
What is the innervation to the dilator muscle of the iris? What is the result? What is the NT and receptor?
Sympa -> dilate
NE on alpha 1 receptor
If you have an ocular sympathetic lesion, what would you see?
Normal = dilate Lesion = miosis (Horner's)
What is the innervation to the sphincter muscle of the iris? What is the result? What is the NT and receptor?
Para -> constrict
ACh on M3 receptors
If you have an ocular para lesion, what would you see?
Blown pupil (dilation)
What drug do you use to dilate pupil for lazy eyes?
Atropine
What would the effect of alpha1 agonist eyedrops be? What is the drug?
Phenylephrine
- Activate sympa –> dilation
What would the effect of a cholinergic antagonist be? What is the drug?
Tropicamide
Antagonize sphincter muscle activation - prevent miosis
Drugs that dilate your eyes
Atropine = muscarinic antagonist Phenylephrine = a1 agonist Tropicamide = cholinergic antagonist
What drug do you use to reverse dilation you just cause via drugs?
Dapiprazole = alpha blocker
What are the SC of sympathetic overload?
“Mad as a hatter, dry as a bone”
Dry skin, mouth + constipation + urine retention
Irritable, delirious
Tachycardia
1 blown pupil differential
Intracranial pathology
Or you accidentally touched your eye with dilator
Define glaucoma
Optic disc atrophy due to death of ganglion cells
What is the only treatable risk factor for glaucoma?
↑IOP
4 types of glaucoma
- Open angle - dilation makes better
- Angle closure - dilation causes acute angle closure attack
- Secondary
- Childhood
Where is this angle we’re talking about
Bet iris & cornea
Describe open angle patho
Due to increase aqueous production (maybe… unclear)
Treat to ↓production or ↑outflow
Describe closed angle patho
Narrow angle means can’t drain –> pressure builds up
4 drug classes to treat glaucoma and specific drugs for each
Beta antagonists - Timolol (non-selective) A2 agonist - Brimonidine - Apraclonidine Cholinergic agonists - rarely used - Pilocarpine - Caramylcholine Cholinergic antagonist - Tropicamide
Where do cholinergic agonists work to treat glaucoma
Trabecular meshwork
Constrict pupil –> increase angle
Better outflow
Where do B antagonists and A agonists work to treat glaucoma
Ciliary body
↓aqueous production
Which drugs might cause acute angle closure attack
Anti-cholinergics
If on these meds and naturally have narrow angle
Why is the goal to target B1 > B2 receptors for antagonists?
B2 antagonism = potential pulm SE
B1 is cardio-selective
What are the potential SE from BBs?
“Feel slower” - CNS depression, ↓BP
Symptoms of Horner’s sydrome
Ptosis, miosis, anhydrosis
1st step in Horner’s diagnosis - explain mechanism
"Is this Horner's" Cocaine Increases NE in synapse b/c X NET reuptake Normal = see dilation Horner's = maintained constriction
2nd step in Horner’s diagnosis - explain mechansim
"Localize the lesion" Amphedamine Pre-synaptically releases NE See dilation = 1st or 2nd order neuron lesion Still constricted = 3rd order lesion
Which drug could you use instead of amphedamine
Apriclonidine = A2 selective agonist w/ weak A1 effect
Normal pts won’t see dilation
Horner’s pts - hypersensitive to A1 b/c A2 isn’t working –> dilate
