Ocular pharmacology

Question 1

WHAT TEAM?!

Answer 1

WILDCATS!!!

Question 2

Corneal penetration

• epithelium/stroma is soluble to what
• what can change the nature of the epithelium

Answer 2

-epithelium- hydrophobic (lipid soluble drugs penetrate)
stroma- hydrophilic (water soluble drugs penetrate)

-inflammation

Question 3

Topical steroids

• how to make them penetrate both epithelium and sclera?
• examples

Answer 3

-chemical modification: acetate is hydrophobic
phosphate is hydrophilic

-prednisolone acetate- good penetration to cornea
prednisolone phosphate- poor penetration to cornea

Question 4

Name the 3 drugs used to treat ocular infection

Answer 4

chloramphenicol
aciclovir
ofloxacin

Question 5

treatment of inflammation

• agents used (4)
• action of steroids and 3 uses

Answer 5

-steroids, topical NSAIDs, antihistamines, mast cell stabilisers

-to suppress inflammation, allergy and immune response
used in: post cataract op, uveitis and to prevent corneal graft rejection

Question 6

What is temporal arteritis

-treatment?

Answer 6

new onset headache and pain in the jaw on chewing
temporal arteries hard and ropy

-systemic steroids

Question 7

steroids

• SE- ocular (3) and systemic (6)
• name 2 corneal and 3 intra-ocular steroids

Answer 7

-cataract, glaucoma and exacerbation of viral infection
gastric ulceration, immunosupression, osteoporosis, weight gain, diabetes, neurophsychiatric effects

-corneal: flueromethalone and prednisolone drops
intra-ocular: betamethasone, dexamethasone and prednisolone

Question 8

glaucoma

• what is it?
• presentation (2)
• treatment (5)

Answer 8

-group of diseases characterised by progressive optic neuropathy causing visual field defects and raised intra ocular pressure

-asymptomatic and picked up by screening
chronic and progressive with central vision preserved

-Drops:
prostanoids open the uveal scleral outflow e.g. latanoprost
beta blockers block the ciliary body e.g timolol and betaxolol
carbonic anhydrase inhibitors block the ciliary body e.g topical dorzolamide
alpha adrenergic agonist increases outflow from vessels e.g Brimonidine
parasympathomimetic opens up trabecular network and pulled iris tight e.g pilocarpine

Question 9

treatment for wet macular degeneration

Answer 9

anti-VEGF injections

Question 10

what drops should be used during a corneal scrape?

Answer 10

local anaesthetic: block Na channels and impedes nerve conduction

Question 11

name the most commonly used diagnostic dye

-used in what (3)

Answer 11

fluorescein

-to show corneal abrasion
tonometry
diagnosing naso-lacrimal duct obstruction

Question 12

What drops cause pupillary dilatation? (2)

• mode of action
• examples
• SE

Answer 12

Mydriatics and sympathomimetics

-Mydriatics:
block the parasympathetic nerve supply
e.g. tropicamide, cyclopentolate
SE- acute closed angle glaucoma

-sympathomimetics
acts on the sympathetic system
e.g. phenylephine

Question 13

Name the important drugs to ask for in ocular drug hx an what they cause (5)

Answer 13

-Vigabatrin (epilepsy)- constricts visual field
steroids- cataracts
Ethambutol- optic neuroptahy
chloroquine- bulls eye maculopathy
amioderone- corneal verticillata