Glaucoma

Question 1

what is mechanisms used for secretion of aqueous humor?

Answer 1

1) carbonic anhydrase: secreted by the epithelium of ciliary body

flows into the space in front of the iris, through the trabecular meshwork, and exits via the canal of Schlemm

Question 2

what is glaucoma?

Answer 2

Degenerative disease of optic nerve associated with painless (asymptomatic) loss of vision, increased intraocular pressure

Question 3

what are the 2 Clinical types of Glaucoma?

Answer 3

1. Closed angle (Acute congestive Glaucoma)
2. Open angle Glaucoma

Question 4

what are the 2 causes of glaucoma?

Answer 4

1. Excess synthesis or secretion of aqueous humor
2. Reduced drainage or outflow of Aqueous humor

Question 5

Glaucoma therapy is aimed at?

Answer 5

• Reduce production
• Facilitate the drainage

Question 6

what drugs are used to treat glaucoma by reducing the production?

Answer 6

• Dorzolamide
• Acetazolamide
• Timolol
• Betoxolol
• apraclonidine
• Brimonidine

Question 7

What drugs can be used in order to treat glaucoma by Facilitating the drainage?

Answer 7

• Mannitol
• Latanoprost

Question 8

latanoprost uses what mechanisms?

Answer 8

PGF2alpha analog

Question 9

what mechanisms can be used for the reduction of aqueous humor production?

Answer 9

• Beta blockade
• Alpha 2 selective agonists
• Carbonic anhydrase inhibition

Question 10

What drugs can be used for beta blockade mechanism in reduction of humor production?

Answer 10

• timolol - topical eye drops Non-selective β blockade
• betaxolol - eye drops Selective β1 blockade

Question 11

why do beta blockers work in reducing the aqueous humor production?

Answer 11

Production and secretion of aqueous humor from the ciliary body epithelium is adrenergic beta receptor mediated.

Question 12

What drugs can be used for alpha 2 selective agonist mechanism in reduction of aqueous humor production?

Answer 12

Apraclonidine, Brimonidine topical eye drops

Question 13

What drugs can be used for carbonic anhydrase inhibition in reduction of aqueous humor production?

Answer 13

Acetazolamide (oral), Dorzolamide (topical) : reduce the synthesis of aqueous humor by inhibitng the enzyme carbonic anhydrase.

Question 14

what antimuscarinic drugs do you have to screen for a history of glaucoma before giving it to the patient?

Answer 14

anticholinergics, antipsychotics, TCA, Meperidine (opiod), H1 antihistamines

Question 15

What drugs can increase the outflow of aqueous humor?

how do they cause this effect?

Answer 15

• Topical Pilocarpine, ecothiopate and physostigmine:
  
  • These drugs causes Ciliary muscle contraction which increases the Irido-corneal angle and open the trabecular meshwork
• Prostaglandins: Latanoprost
  • increase the outflow through uveoscleral meshwork
• Mannitol
  
  • reduces IOP by reducing vitreous volume

Question 16

What is closed angle glaucoma?

Answer 16

sudden opposition of the peripheral iris with the trabecular meshwork, and leads to the obstruction of canal of Schlemm through which aqueous humor drains out

Question 17

what Two important group of drugs induces sudden closure of the irido-corneal angle?

what may they cause?

Answer 17

Mydriatics : Anti-cholinergic drugs

Antidepressants : SSRI drugs

can cause/Precipitate glaucoma