Glaucoma

Question 1

What is Glaucoma?

Answer 1

Optic neuropathy with typical field defect usually associated with ocular HTN (intra-ocular pressure > 21 mm Hg)
1/6 pts have normal IOP

Question 2

Describe the aetiology of glaucoma

Answer 2

POAG: angle between iris + cornea is open but trabecular meshwork drainage system slowly gets clogged over time by blood or inflammatory cells.
ACAG: angle is too small due to the lens being pushed against the iris.
Over time, this causes ocular HTN which causes compression + stretching of the retinal nerve fibres.
Leads to scotomas (partial loss of vision) + visual field defects.

Question 3

List the primary causes of glaucoma

Answer 3

Acute closed-angle glaucoma (ACAG)
Chronic closed-angle glaucoma
Primary open-angle glaucoma (POAG)

Question 4

List 5 secondary causes of glaucoma

Answer 4

Trauma
Uveitis
Steroids
Rubeosis iridis (formation of new blood vessels on surface of the iris)
Congenital: Buphthalmos (enlargement of eye balls)

Question 5

Describe the epidemiology of glaucoma

Answer 5

1% in > 40 yrs
10% in >80 yrs
3rd most common cause of blindness worldwide

Question 6

List 5 symptoms of Acute closed-angle glaucoma (ACAG)

Answer 6

Painful red eye  
Impaired vision  
Halo's seen around lights  
N+V  
Headache

Question 7

What are the symptoms of Primary open-angle glaucoma?

Answer 7

Usually ASYMPTOMATIC

Peripheral visual field loss

Question 8

List 8 signs of Acute closed-angle glaucoma (ACAG)

Answer 8

Red eye  
Hazy cornea  
Loss of red reflex  
Fixed + dilated pupil 
Eye is tender + hard on palpation  
Cupped optic disc  
Visual field defect  
Moderated raised intra-ocular pressure

Question 9

Describe signs of Primary open-angle glaucoma

Answer 9

Optic disc may be cupped

Usually NO signs

Question 10

List 5 investigations that may be used in glaucoma

Answer 10

Gonioscopy: Assess iridocorneal angle
Goldmann Applanation Tonometry: intra-ocular pressure
Pachymetry: central corneal thickness (CCT)
Fundoscopy: cupped optic disc
Perimetry (Visual Field Testing)

Question 11

List 4 risk factors for glaucoma

Answer 11

Female
Far-sighted (hyperopia)
Increased age
Shallow peripheral anterior chamber

Question 12

Describe the normal production and passage of aqueous humour

Answer 12

Aqueous humor secreted by ciliary epithelium into the posterior chamber.
From here, flows in to a narrow space between front of lens + back of iris, to enter the anterior chamber.
From here, it flows out via the trabecular meshwork + through the canal of Schlemm to enter the aqueous vein.

Question 13

Give 2 symptoms of congenital bupthalmos glaucoma

Answer 13

Watering

Cloudy cornea