Chronic Glaucoma (Open-Angle Glaucoma)

Question 1

Pathophysiology of Open-Angle Glaucoma (Chronic Glaucoma) (2).

Answer 1

1. Gradual slow increase in resistance through the trabecular meshwork, making it more difficult for aqueous humour to exit.
2. Optic Neuropathy with the death of optic nerve fibres with/without raised IOP.

Question 2

Risk Factors of Open-Angle Glaucoma (Chronic Glaucoma) (7).

Answer 2

1. Increasing Age.
2. Family History.
3. Afro-Caribbean Ethnicity.
4. Myopia (Near-Sightedness).
5. Hypertension.
6. Diabetes Mellitus.
7. Corticosteroid Use.

Question 3

Clinical Features of Open-Angle Glaucoma (Chronic Glaucoma) (4).

Answer 3

1. Asymptomatic for a long period of time.
2. Affects peripheral vision first - closes in gradually (nasal scotomas), leading to tunnel vision.
3. Complaints : Knocking into objects or having to dodge cars.
4. Gradual Onset of Fluctuating Pain, Headaches, Blurred Vision, Halos around Lights (at Night).

Question 4

Fundoscopy Signs of Open-Angle Glaucoma (Chronic Glaucoma) (5).

Answer 4

1. Optic Disc Cupping (Cup : Disc Ratio > 0.7).
2. Optic Disc Pallor (Optic Atrophy).
3. Bayonetting of Vessels (Vessels have breaks as they disappear into the deep cup and reappear at the base).
4. Cup Notching.
5. Disc Haemorrhages.

Question 5

Management of Open-Angle Glaucoma (Chronic Glaucoma) (5).

Answer 5

1. Aim : Reduce IOP.
2. Start : IOP = 24mmHg+. Follow up to assess response to treatment.
3. 1st Line - Prostaglandin Analogue Eye Drops.
4. 2nd Line - Triad Combination Eye-drops.
5. 3rd Line - Trabeculectomy Surgery.

Question 6

Indication of a Trabeculectomy.

Answer 6

Where eye drops are ineffective.

Question 7

Trabeculectomy Surgery.

Answer 7

A new channel is created from the anterior chamber through the sclera to a location under the conjunctive (a bleb under the conujunctiva) where the aqueous humour can drain and be resorbed into the general circulation.