Glaucoma Pharmacology
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Transcript of Glaucoma Pharmacology
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7/29/2019 Glaucoma Pharmacology
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Pharmacology of the Eye
Edward JN Ishac
Department of Pharmacology and Toxicology
Medical College of VirginiaCampus of Virginia Commonwealth UniversityRichmond, Virginia, USA
Smith Building, Room [email protected] 8-2126
Pharmacology of the Eye
The eye is a good example ofan organ with multiple ANS
functions, controlled by several different autonomicreceptors. (Katzung)
Increased intraocular pressure: Untreated blindness
Glaucoma:
- Open-angle (wide, chronic) treated with beta-
blockers and other agents
- Closed-angle (narrow-angle) dilated iris can
occlude outflow. Pilocarpine or surgical removal of
part of iris (iridectomy)
GlaucomaIncreased intraocular pressure: Untreated blindness
Glaucoma:- Open angle (wide, chronic) treated with beta-blockers and other agents- Closed-angle (narrow-angle) dilated iris can occlude outflow
Pilocarpine or surgical removal of part of iris (iridectomy)
Glaucoma treatment
1. -Agonist: Outflow2. M-Agonists: Outflow3. -Blocker:Secretion4. 2-Agonist: Secretion
5. Prostaglandins: Outflow6. Carbonic acid inhibitors: Secretion
Ach effects on smooth muscle in the eye
Contraction of sphincter muscle miosis
Contraction of ciliarymuscle for near vision
Actions on the EyeGlaucoma treatment
1. -AgonistOutflow
2. M-Agonists
Outflow
3. -BlockerSecretion
4. 2-AgonistSecretion
5. Prostaglandins Outflow
6. Carbonic acidinhibitors
Secretion
Drugs used in glaucoma
Cholinomimetics
Pilocarpine, physostigmine,echothiophate
Ciliary muscule contraction opening of trabecular
meshwork outflow
Topical
Alpha Agonists: Unselective:Epinephrine
Outflow Tropical
Alpha2-Selective Agonists:
Apraclonidine
Aqueous secretion from theciliary epithelium
Topical
Beta-Blockers :Timolol, betaxolol, carteolol
Aqueous secretion from theciliary epithelium
Topical
Secretion due to lack ofHCO3
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OralTopical
Diuretics: Carbonic acid inhi b.Acetazolamide, Methazolamide
Dorzolamide, Brinzolamide
Outflow TopicalProstaglandins:
Latanoprost
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Innervation of the iris
Clinical Setting Drug Pupillary Response
Normal Sympathomimeticie. phenylephrine
Dilation (mydriasis)
Normal Parasympathomimeticie. pilocarpine
Constriction (miosis)
Normal Parasympatholytic
ie. atropine
Mydriasis,
cyclopegia
Horners syndrome Cocaine 4-10% No dilation
P re ga ng li on ic H orn er s Hy droxy amph etami ne Di la ti on
Postgangl ioni c Horner s Hydroxyamphetamine No di la ti on
Adies pup il Pilocarpine 0.05-0.1% Constriction
Normal Opioids (oral or
intravenous)
Pinpoint pupils
Effects of pharmacological agents on the pupil
Eye - Horners Syndrome
Destruction of Sympathetic innervation to the iris
- loss of preganglionic fibers- loss of postganglionic fibers
- parasympathetic innervation left unopposed
Horners Syndrome (note sagging left eyelid and miosis)
Adies Pupil & Iritis
Iritis
Muscarinic blocker to dilate pupil
to prevent attachment to lens.Steroid to treat inflammation.
Adies PupilPoor light reflex
Topical scopolamine drops on pupil diameter and accommodation. inthe normal human eye. One drop (0.5%) at zero time and 30 min.