Diseases of the Eye

Question 1

1. Where is aqueous humor produced?
2. Where does it flow?
3. How does it drain?

Answer 1

1. Secreted by blood vessels in the ciliary body
2. Flows through the anterior chamber and pupil
3. Drained via trabecular network, canal of Schlemm, episcleral vein, uveoscleral outflow

Question 2

What things are targeted for affecting aqueous humor production?

Answer 2

Carbonic anhydrase and a and B adrenoreceptors

Question 3

What drug classes decrease aqueous humor production? What would you use these to treat?

Answer 3

a1 and a2 agonists, B1 antagonists, carbonic anhydrase inhibitors; treat glaucoma

Question 4

What do carbonic anhydrase inhibitors do?

Answer 4

Reduce bicarb production –> active transport of bicarb is required for aqueous humor production

Question 5

What causes glaucoma? What determines intraocular pressure?

Answer 5

Glaucoma is elevated intraocular pressure due to poor drainage of aqueous humor
**Intraocular pressures is an equilibrium state between aqueous humor production vs. rate of drainage

Question 6

Timolol, betaxolol, carteolol, levobunolol, metipranolol

1. Use
2. Mechanism

Answer 6

1. Open angle glaucoma
2. B antagonists: block B1 receptors on ciliary body
   * *Reduce aqueous humor production

Question 7

Epi, dipivefrin, apraclonidine

1. Use
2. Mechanism

Answer 7

1. Open angle glaucoma
2. alpha agonists: stimulate a2 receptors on ciliary body and/or a1 receptors on ciliary vessels
   * *Reduce aqueous humor production

Question 8

Acetazolamide, dichlorphenamide, dorzolamide

1. Use
2. Mechanism

Answer 8

1. Open angle glaucoma
2. Carbonic anhydrase inhibitors: reduce HCO3- production
   * *Reduce aqueous humor production

Question 9

Carbachol, pilocarpine

1. Use
2. Mechanism

Answer 9

1. Open angle glaucoma
2. Miotics: stimulate M3 receptors on iris and ciliary body which improves uveoscleral outflow
   * *Increase aqueous humor drainage

Question 10

How is closed angle glaucoma treated?

Answer 10

Acute treatment:
Systemic treatment with mannitol or glycerol to decrease intraocular pressure, topical biotic application to tighten the iris temporarily
Cure: YAG laser surgery to create small hole in the iris

**DO NOT give mydriatics