Chronic open angle glaucoma

Question 1

Pathophysiology

Answer 1

↑ resistance to aqueous fluid outflow via the trabecular meshwork

↑IOP

Optic nerve damage

Question 2

What does open mean?

Answer 2

Open anterior iridocorneal angle

Question 3

What does:

• Glaucoma
• Normal-tension glaucoma
• Ocular hypertension

Mean?????

Answer 3

Any optic neuropathy featuring loss of nerve fibres - ↑IOP most common cause

When IOP is normal and there is still neuropathy

Raised IOP without visual field and optic nerve head damage

Question 4

S+S:

How long does it remain asymptomatic?

5 stages of vision loss

Answer 4

Until late-stage

Paracentral scotoma 
Superior nasal fields lost 
Temporal vision lost 
Tunnel vision 
Complete loss of vision

Question 5

Fundoscopy:

What happens to the optic disc in earlier disease?

What happens in late disease?

Answer 5

Optic cupping (Increased cup : disc ratio)

Optic atrophy so pale

Question 6

Investigations:

What exam is used to look at optic disc?

What is an optical coherence tomography and why is it used?

What is automated perimetry and why is it used?

What does tonometry do?

What does gonioscopy do and why is it relevant?

What is pachymetry and what can it help determine?

Answer 6

Slit-lamp exam

A non-invasive imaging test. OCT uses light waves to take cross-section pictures of your retina. With OCT, your ophthalmologist can see each of the retina’s distinctive layers.

Assesses optic nerve and fundus assessment 
-----
Assess the central visual field 
----
Assess IOP (Rx done for >24mmHg)
----
Measures iridocorneal angle 
----
Measures corneal thickness to help interpret IOP and determine risk of progression of OHT to COAG.

Question 7

Management - IOP lowering Rx for COAG:

Prostaglandin analogue eye drops - MOA? Name - L

Beta-blockers - name - T
Alpha agonists - name - B
Carbonic anhydrase inhibitor - name - B

MOA of previous 3?

What laser/surgical Rx can be done if all this Rx is ineffective?

Answer 7

Increase aqueous outflow
‘Latanoprost’

Timolol
Brimonidine
Brinzolamide

Laser trabeculoplasty
Surgical trabeculectomy - increases outflow through the trabecular meshwork

Question 8

Management:

What is done for OHT patients?

What about NTG patients?

Answer 8

Topical therapy to prevent progression to COAG

Monitoring only

Question 9

Management:

What do you need to make sure to tell the patient?

Who should be contacted?

What should you encourage them to do?

Answer 9

EXPLAIN THE IMPORTANCE of taking meds to prevent progression

DVLA

Official registration to aid access to benefits

Question 10

Complications

Answer 10

Eventual blindness without Rx