Primary Open-Angle Glaucoma

Question 1

What is primary open-angle glaucoma (POAG)?

Answer 1

A chronic, progressive condition characterised by optic neuropathy and visual field loss, associated with raised intraocular pressure.

Question 2

What causes POAG?

Answer 2

Impaired drainage of aqueous humour through the trabecular meshwork, leading to increased intraocular pressure.

Question 3

What are the risk factors for POAG?

Answer 3

Age, family history, African or Hispanic ethnicity, myopia, diabetes, and prolonged corticosteroid use.

Question 4

What are the typical symptoms of POAG?

Answer 4

POAG is often asymptomatic in the early stages; later, peripheral vision loss occurs, leading to “tunnel vision.”

Question 5

How is POAG typically detected?

Answer 5

During routine eye exams, with findings such as raised intraocular pressure, optic disc cupping, and visual field defects.

Question 6

What is the pathophysiology of POAG?

Answer 6

Progressive optic nerve damage occurs due to mechanical compression or vascular insufficiency from elevated intraocular pressure.

Question 7

What is the prevalence of POAG?

Answer 7

POAG is one of the leading causes of irreversible blindness worldwide, particularly in older adults.

Question 8

What is the normal range for intraocular pressure (IOP)?

Answer 8

10–21 mmHg, but optic nerve damage can occur even at normal pressures in normal-tension glaucoma.

Question 9

What are the characteristic fundoscopic findings in POAG?

Answer 9

Optic disc cupping (enlarged cup-to-disc ratio) and thinning of the neuroretinal rim.

Question 10

What is the role of visual field testing in POAG?

Answer 10

It detects peripheral vision loss and maps visual field defects characteristic of glaucoma.

Question 11

What is the role of optical coherence tomography (OCT) in POAG?

Answer 11

OCT measures retinal nerve fibre layer thickness to detect early optic nerve damage.

Question 12

What are the first-line medications for POAG?

Answer 12

Prostaglandin analogues (e.g., latanoprost) to increase aqueous humour outflow.

Question 13

What are the common side effects of prostaglandin analogues?

Answer 13

Eye redness, eyelash growth, and darkening of the iris or periocular skin.

Question 14

What is the role of beta-blockers in POAG?

Answer 14

Beta-blockers (e.g., timolol) reduce aqueous humour production.

Question 15

What is the role of carbonic anhydrase inhibitors in POAG?

Answer 15

These drugs (e.g., dorzolamide) decrease aqueous humour production.

Question 16

What is the role of alpha agonists in POAG?

Answer 16

Alpha agonists (e.g., brimonidine) reduce aqueous humour production and increase uveoscleral outflow.

Question 17

What is selective laser trabeculoplasty (SLT)?

Answer 17

A laser treatment that improves aqueous humour drainage through the trabecular meshwork.

Question 18

What are the surgical options for POAG?

Answer 18

Trabeculectomy, aqueous shunt implants, or minimally invasive glaucoma surgeries (MIGS).

Question 19

What are potential complications of untreated POAG?

Answer 19

Progressive vision loss leading to blindness, optic nerve damage, and reduced quality of life.

Question 20

What is normal-tension glaucoma?

Answer 20

A subtype of POAG where optic nerve damage occurs despite normal intraocular pressure levels.

Question 21

What lifestyle modifications can help manage POAG?

Answer 21

Regular eye exams, avoiding smoking, maintaining a healthy weight, and controlling systemic conditions like diabetes.

Question 22

Why is POAG often called the “silent thief of sight”?

Answer 22

Because it progresses slowly and painlessly, causing significant damage before symptoms appear.

Question 23

What is the role of compliance in POAG management?

Answer 23

Adherence to prescribed medications and regular follow-ups is critical to prevent progression of the disease.

Question 24

How does POAG differ from acute angle-closure glaucoma?

Answer 24

POAG is chronic and painless with gradual vision loss, while acute angle-closure glaucoma is sudden, painful, and requires emergency treatment.

Question 25

Why is early detection important in POAG?

Answer 25

Early detection and treatment can prevent irreversible vision loss and preserve quality of life.