Ophthalmology

Question 1

What is glaucoma?

Answer 1

Blockage in aqueous humour drainage -> increased intraocular pressure -> damage to optic nerve

Question 2

What is the normal intraocular pressure?

Answer 2

10-21mmHg

Question 3

What does increased pressure in the eye do to the optic disc?

Answer 3

Causes cupping, optic cup increases in size (usually <0.5x the size of the optic disc)

Question 4

Give 4 RFs for open angle glaucoma

Answer 4

• Increasing age
• FHx
• Black ethnic origin
• Nearsightedness (myopia)

Question 5

How does open angle glaucoma affect vision? (3)

Answer 5

Peripheral vision loss
Blurry vision
Halos around lights (worse at night)

Question 6

Glaucoma diagnosis. How are the following assessed:

1) Intraocular pressure
2) Optic disc cupping + optic nerve health
3) Peripheral vision loss

Answer 6

Goldmann applanation tonometry to check intraocular pressure.

Fundoscopy to check optic disc cupping and optic nerve health.

Visual field assessment to check for peripheral vision loss.

Question 7

What is the threshold of intraocular pressure at which glaucoma treatment is started?

Answer 7

IOP of 24mmHg or above

Question 8

First line treatment for open angle glaucoma? How do they work?

Answer 8

Prostaglandin analogue eye drops (latanoprost)

Increase uveoscleral outflow

Question 9

Give 3 SEs of prostaglandin analogue eye drops (e.g. latanoprost)

Answer 9

Eyelash growth
Eyelid pigmentation
Iris pigmentation (‘browning’)

Question 10

Prostaglandin analogue eye drops are first line treatment for open angle glaucoma. Give 3 other medical treatments that can be used.

Answer 10

BB (e.g. timolol): reduces production of aqueous humour

Carbonic anhydrase inhibitors (e.g. dorzolamide): reduces production of aqueous humour

Sympathomimetics (e.g. brimonidine): reduces production of aqueous fluid + increase uveoscleral outflow

Question 11

If medical management of open angle glaucoma is ineffective, what treatment may be offered?

Answer 11

If eye drops are ineffective, TRABECULECTOMY surgery may be required: creation of new channel from the anterior chamber through the sclera to a location under the conjunctiva.

Question 12

What happens in acute angle closure glaucoma?

Answer 12

Iris bulges forwards -> seals off trabecular meshwork from anterior chamber -> aqueous humour builds up rapidly leading to increased pressure

Question 13

Give 5 RFs for acute angle closure glaucoma

Answer 13

Increasing age,
Female gender (4x higher),
FHx,
Chinese + East Asian origin,
Shallow anterior chamber

Question 14

What 3 types of medication can trigger acute angle closure glaucoma?

Answer 14

Adrenergic, e.g. noradrenaline
Anticholinergic, e.g. oxybutynin, solifenacin
Tricyclic antidepressants, e.g. amitryptiline

Question 15

How does acute angle closure glaucoma present?

Answer 15

Generally unwell, with:
Painful, red, watering eye
Blurred vision, halos around lights
Headache
N+V

Question 16

Give 7 features on examination in a patient with acute angle closure glaucoma

Answer 16

Red eye |
Watering/teary |
Hazy cornea |
Decreased visual acuity |
Dilatation of affected pupil |
Fixed pupil size |
Firm eyeball on palpation |

Question 17

What is the management for acute angle closure glaucoma?

Answer 17

IMMEDIATE referral to ophthalmology

Whilst waiting for ambulance:

• Lie on back without pillow
• Pilocarpine eye drops (2% for blue, 4% for brown eyes)
• Acetalozamide 500mg PO
• Analgesia + antiemetic PRN

Laser iridotomy = definitive treatment