Glaucoma

Question 1

What is glaucoma?

Answer 1

Group of eye disease causing progressive occular neuropathy

Raised Intra-occular pressure is important modifiable risk factor (not cause)

Question 2

What is the prevalence of glaucoma?

Answer 2

Common (worldwide ca. 45 million)

Second leading cause of blindness

• 1/3 angle-closure glaucoma, which is more likely in women aged 55-65 and asian population
• Primary open-angle glaucoma 70% of cases

Question 3

What are the different types of glaucoma that someone could present with?

Answer 3

1. Open angle glaucoma
   
   1. Primary (70% of cases)
   2. Secondary (due to underyling disease, rare)
2. Angle-closure glaucoma 1/3 of cases
   
   1. Primary (more common)
   2. Secondary
3. Normal/Low Tension Glaucoma

Question 4

What is a Primary-open angle glaucoma?

Answer 4

Glaucoma with raised intra-ocular pressure due to reduced drainage in anterior chamber

• Blocked Trabecular meshwork
• Might also be due to increased production of aqueous humor

Question 5

What is a primary angle-closure glaucoma?

Answer 5

• Angle between cornea and iris is at least partially closed –> no drainage of aqueous humour from posterior to anterior chamber of eye
• Increased intra-ocular pressure

Question 6

What is the reason for a normal/ low tension glaucoma?

Answer 6

Not known, no increased intra-ocular pressure

• Possibly due to hypoperfusion of optic nerve or genetic hypersensitivity of pressure that are in normal range

Question 7

How does raised intra-ocular pressure predispoes to glaucoma?

Answer 7

Raised intra-ocular pressure might cause damage to the retinal ganglion

Question 8

What ar symptoms of primary open-angle glaucoma

Answer 8

initially asymptomatic

• might cause peripheral visual field
• Progression into central visual field loss

Question 9

What are risk factors for the development of glaucoma?

Answer 9

• Raised intra-ocular pressure (>21mmHg)
• Trauma/surgery
• For open-angle
  
  • >40years
  • African descent
  • DM
  • Myopia
  • FH

Question 10

What are Symptoms of angle-closure glaucoma?

Answer 10

Sudden onset, severe raised intra-cranial pressure leading to

• Eye pain
• Redness
• Blurry vision
• Headache
• Nausea and vomiting

Question 11

What are signs on examination of open-angle glaucoma?

Answer 11

• Cupping of optic disc
• Pallor of optic disc with kinked vessels at edges of optic disc

Question 12

What are signs of angle-closure glaucoma on examination?

Answer 12

fixed, dilated pupil that is minimally responsive to light and cupping of the optic disc

Question 13

Which investigations would you order in a patient with suspected glaucoma?

Answer 13

• Tonometry - assess intra-occular pressure
  
  • normal 14-21 mmHg
• Visual field testing
  
  • Might see signs of peripheral vision loss
• Imaging for optic nerve damage
  
  • Or direct observation “cupping”