Eyes: glaucoma

Question 1

What is glaucoma?

Answer 1

• Glaucoma is a range of disorders usually characterised by raised intraocular pressure and leading to damage of the optic nerve
• Damage to the ocular nerve can also occur at normal
  intraocular pressure
• The most common form is primary open-angle glaucoma
• It is caused by a blockage in the trabecular meshwork, which drains the anterior chamber of the eye to the episcleral veins through the Schlemm’s canal
• Primary angle-closure glaucoma is a medical emergency!!!

Question 2

What are the symptoms of open angle glaucoma OAG

Answer 2

• Usually asymptomatic
• Symptoms include worsening vision
• Raised intraocular pressure

Question 3

How do you manage OAG

Answer 3

• Beta blockers
• Prostaglandin analogues
• Sympathomimetics
• Carbonic anhydrase inhibitors
• Miotics

Question 4

List the beta blockers used in OAG

Answer 4

• Betaxolol
• Levobunolol
• Timolol

Question 5

How do beta blockers work in OAG

Answer 5

• By reducing the rate of production of aqueous humour

Question 6

What are the contraindications and side effects of beta blockers for OAG

Answer 6

• SAME AS SYSTEMATIC
• Therefore cautioned (if applied locally) in asthma and COPD
• Other side effects are local e.g. discomfort, eye inflammation

Question 7

List the prostaglandin analogues

Answer 7

1. Latanoprost
2. Tafluprost
3. Travoprost
4. Bimatoporst

Question 8

How do prostaglandin analogues work?

Answer 8

• They increase uveoscleral outflow and subsequently reduce intra-ocular pressure

Question 9

What are the main side effects of prostaglandin analogues you should be aware of?

Answer 9

1. Changes to eye colour
   - An increase in brown pigments to the iris can occur
2. Changes to eyelashes (increase length)
   - Warn patients that if they apply the medication to the surrounding skin, it can increase hair growth

Question 10

List the sympathomimetics used in OAG

Answer 10

1. Brimonidine
2. Apraclonidine

Question 11

How do sympathomimetics work in OAG

Answer 11

• They are alpha2-adrenoreceptors agonists
• They lower intra-ocular pressure by reducing aqueous humour formation and increasing uveoscleral outflow

Question 12

When are sympathomimetics used in OAG

Answer 12

• When intra-ocular pressure is not controlled with beta bockers
• OR in addition to other treatments

Question 13

List the carbonic anhydrase inhibitors used in OAG

Answer 13

1. Acetazolamide
2. Brinzolamide
3. Dorzolamide

Question 14

How do carbonic anhydrases work

Answer 14

• They reduce intra-ocular pressure by reducing aqueous humour production
• Usually used when resistant to beta blockers or in addition to other drugs

Question 15

Which miotic is used in glaucoma

Answer 15

Pilocarpine

Question 16

Is pilocarpine normally used in open angle glaucoma

Answer 16

• No poorly tolerate due to side effects
• Normally used in close angle glaucoma