Glaucoma and ocular hypertension

Question 1

Glaucoma causes

Answer 1

the loss of vision due to optic disc and nerve damage. It is mainly caused by raised intra-ocular pressure however it can also occur when intra-ocular pressure is normal.

Question 2

Other risk factors of glaucoma include

Answer 2

age, family history, ethnicity, corticosteroid use, myopia, type 2 diabetes mellitus, CVD + hypertension.

Question 3

The most common form of glaucoma is

Answer 3

chronic open-angle glaucoma (also known as primary open-angle glaucoma) where drainage of the aqueous humour through the trabecular meshwork is restricted, and the angle between the iris and the cornea is normal. Initially, this condition tends to be asymptomatic, however, as glaucoma progresses, patients may present with irreversible sight loss or visual field defects.

Question 4

Patients with … are at high risk of developing COAG (chronic open-angle glaucoma).

Answer 4

Patients with ocular hypertension (an intra-ocular pressure >21 mmHg) are at high risk of developing COAG.

Question 5

Acute angle-closure glaucoma is

Answer 5

less common + occurs when outflow of aq. humour from eye is totally obstructed by bowing of the iris against the trabecular meshwork. It is characterised by its abrupt onset of symptoms + is a sight-threatening medical emergency that requires urgent reduction of intra-ocular pressure

Question 6

first-line in patients with an intra-ocular pressure >24 mmHg and who are at risk of visual impairment within their lifetime.

Answer 6

• Prostaglandin analogues (Latanoprost, travoprost, bimatoprost)

Question 7

If first line treatment is not tolerated

Answer 7

• an alternative prostaglandin analogue should be tried before switching to a topical B-blocker (betaxolol, levobunolol hydrochloride, or timolol maleate).

Question 8

Topical B-blockers are not recommended in patients with

Answer 8

• bradycardia, uncontrolled HF or asthma.

Question 9

Prostaglandin analogues (e.g. latanoprost) may cause

Answer 9

• a change in eye colour (more brown) which may be permanent – this is more of an issue in patients where treatment is only needed in one eye. Contact with the skin can lead to darkening of the skin and hair growth.

Question 10

Carbonic anhydrase inhibitors

Answer 10

• Carbonic anhydrase inhibitors, e.g. Acetazolamide, Brinzolamide and Dorzolamide reduce intra-ocular pressure by reducing aqueous humour production.
• Used if above treatment options not suitable.
• Acetazolamide: is given by mouth or IV (which is painful due to alkaline pH of the solution. It is used adjunct to other treatment to reduce intra-ocular pressure. Not recommended long-term use.
• Brinzolamide and Dorzolamide are topical carbonic anhydrase inhibitors licensed in patients CI or resistant to B-blockers. They are used alone or as an adjunct to topical B-blockers. Brinzolamide can be used as an adjunct to prostaglandin analogue or a2-adrenoreceptor agonist.