Week 130 - Ocular Pharmacology

Question 1

What are methods of administering drugs to the eye?

Answer 1

1) Intravitreal injection
2) Inserts
3) Spray, eye wash
4) Systemic treatment

Question 2

What are sympathomimetics, give an example and their effects

Answer 2

Phenylephrine
Acts on α1-receptors
Mydriasis
Side effects: photophobia, acute glaucoma, hypertension & arrhythmias

Question 3

What are antimuscarinics, give an example and their effects

Answer 3

Atropine, cyclopentolate, tropicamide
Block Mscr Ach receptors
Mydriasis
Side effects: Photophobia, acute glaucoma + atropine may have systemic actions

Question 4

What are parasympathomimetics, give an example and their effects

Answer 4

Pilocarpine
Mimic Ach effect on Mscr - treat glaucoma
Open up drainage channels in trabecular meshwork
Reverse mydriasis (in around 30 mins)
Side effects: headache, myopia, risk of retinal of detachment

Question 5

What is the effect of Timolol?

Answer 5

Aqueous humour production inhibition

beta-blocker

Question 6

What is the effect of acetazolamide (po), dorzolamide (top)?

Answer 6

Carbonic anhydrase inhibitors - treatment of glaucoma

Question 7

Name (4) artificial tears and lubricants

Answer 7

1) Hypromellose - first line, aqueous layer
2) Carbomers (Viscotears) - Thixotrophic to prolong retention
3) Polyvinyl alcohol (Liquifilm tears) - surfactant, good replacement for mucin layer
4) Ointments (Lacrilube) - Highly viscous (long-lasting), causes blurred vision