Eye practical questions

Question 1

How does tropicamide affect pupil diameter, accommodation and pupil reflex?

Answer 1

increased pupil diameter, decreased accomodation and loss of reflex

Question 2

How does pilocarpine affect pupil diameter, accommodation and pupil reflex?

Answer 2

decreased pupil diameter, increased accomodation and reduction in reflex of pupil constriction

Question 3

What are the three muscles of the eye and innervation?

Answer 3

The sphincter pupillae muscle (circular) - PNS innervation

The ciliary muscle - PNS innervation and SNS

The sphincter dilator muscle (radial) - SNS innervation, blood vessels supplying the eye are under sympathetic control and ciliary muscle

Question 4

Why can the beta blocker timolol be used to treat glaucoma?

Answer 4

Beta 2 receptors when stimulated cause production of aqueous humour so blocking them can lead to reduced production

Question 5

Why can a sympathomimetic drug (dipivefrine) be used to treat glaucoma?

Answer 5

Alpha 1 receptors are activated, causes blood vessel constriction and they reduce blood flow. Resources needed to produce aqueous humour decrease and so production decreases.

Question 6

What is the importance of prostaglandin analogues in terms of treating glaucoma?

Answer 6

Gold standard for glaucoma treatment, venous drainage channels are essentially cleared by prostaglandins rather than just opened a little more by pilocarpine.

Question 7

Why would carbonic anhydrase inhibitors treat glaucoma?

Answer 7

Carbonic anyhydrase is used to from aqueous humour so blocking it will prevent the formation of aqueous humour