Glaucoma

Question 1

Define glaucoma

Answer 1

progressive optic neuropathy associated with characteristic structural damage to the optic nerve and associated visual dysfunction

Question 2

Describe the route of signals from the retina to the brain

Answer 2

rods and cones
photoreceptors
bipolar cells
ganglion cell layer
optic nerve
brain

Question 3

Pathology of glaucoma

Answer 3

death of retinal ganglion cells

Question 4

What is it called when a patient has glaucoma despite normal intraocular pressure?

Answer 4

normal tension glaucoma

Question 5

What is it called when a patient has high intraocular pressure but no glaucomatous damage is present?

Answer 5

ocular hypertension

Question 6

How do you calculate ocular perfusion pressure?

Answer 6

2/3xMAP - IOP

(MAP = DBP + [1/3(SBP-DBP)])

Question 7

Glaucoma risk factors

Answer 7

high intraocular pressure
age
genetics/family history
myopia (short-sightedness)
vascular/haematological

Question 8

Normal intraocular pressure range

Answer 8

10-21 mmHg

Question 9

Describe aqueous drainage

Answer 9

85% through conventional pathway - IOP dependent

15% through uveoscleral pathway - IOP independent

Question 10

How is glaucoma classified?

Answer 10

congenital vs acquired
primary vs secondary
open vs closed/narrow

Question 11

Symptoms of acute primary angle closure glaucoma

Answer 11

pain
red eye
headache
nausea
vomiting
reduced vision
haloes

Question 12

Signs of acute primary angle closure glaucoma

Answer 12

injected eye
corneal oedema
mid-dilated pupil
shallow anterior chamber
closed angle
raised IOP
aqueous flare and cells

Question 13

Acute primary angle closure glaucoma management

Answer 13

Acetazolamide 500mg IV
Pilocarpine 2% drops to both eyes
Dexamethasone drops
lie patient supine

laser peripheral iridotomy = definitive

Question 14

What does acetazolamide do?

Answer 14

causes a reduction in aqueous humour
carbonic anhydrase inhibitor

Question 15

What does pilocarpine do?

Answer 15

allows excess fluid to drain from the eye

cholinergic parasympathomimetic agent. It increase secretion by the exocrine glands, and produces contraction of the iris sphincter muscle and ciliary muscle (when given topically to the eyes) by mainly stimulating muscarinic receptors

Question 16

What equipment is used to measure intraocular pressure?

Answer 16

goldmann tonometer

Question 17

How is glaucoma diagnosed?

Answer 17

IOP
angle assessment
optic disc assessment
visual field assessment

Question 18

How are prostaglandin analogues useful in glaucoma treatment?

Answer 18

increase uveoscleral outflow

Question 19

Prostaglandin analogues examples

Answer 19

Latanaprost, Travaprost, Bimatoprost, Tafluprost

Question 20

Prostaglandin analogues side effects

Answer 20

red eyes
lash growth
darkening of iris colour and skin

Question 21

Name some beta blockers used in glaucoma

Answer 21

Timolol, Betaxolol, Carteolol, Levobunolol, Metipranolol

Question 22

Why are beta blockers used in glaucoma?

Answer 22

reduce aqueous production

Question 23

Name 2 alpha-2 agonists used in glaucoma

Answer 23

Brimonidine, Apraclonidine

Question 24

How do alpha-2 agonists help in glaucoma?

Answer 24

reduce aqueous production
increase uveoscleral outflow

Question 25

What is the vision requirement of the DVLA for group 1 (car) driving?

Answer 25

car number plate at 20m
visual acuity 6/12 or better with both eyes open

no significant defect in central 20 degrees
no significant defect 120 degrees horizontal

Question 26

What is the vision requirement of the DVLA for group 2 (lorry) driving?

Answer 26

Va 6/7.5 in best eye and other eye no worse than 6/60
refraction no worse than +8 dioptres

no defect in central 30 degrees
no significant defect 160 degrees horizontal and 30 degrees either side of horizontal