#44. Primary open-angle glaucoma.

Question 1

What is GLAUCOMA?

Answer 1

Group of Eye conditions that DAMAGE the OPTIC NERVE HEAD

• With a PROGRESSIVE LOSS of RETINAL Ganglion Cells AND their Axons
• Resulting in LOSS of VISUAL FIELD

Question 2

What is PRIMARY OPEN-ANGLE Glaucoma?

Answer 2

• Glaucoma that’s PROGRESSIVE
• CHRONIC Onset
• With the ANTERIOR CHAMBER being open throughout

Question 3

What is the CAUSE of PRIMARY OPEN-ANGLE Glaucoma?

Answer 3

• Unknown Cause
• DRAINAGE of AQEUOUS HUMOUR
• Occurs at NEURORETINAL Tissue of Optic Nerve, leading to COMPRESSION of the Optic Nerve

Question 4

What are the SYMPTOMS of PRIMARY OPEN-ANGLE Glaucoma?

Answer 4

• Asymptomatic (Many years)
• Headaches
• Burning Sensation in Eyes
• Blurred / DECREASED Vision
• Rings of Colours around Light Sources AT NIGHT

Question 5

What is the DIAGNOSIS of PRIMARY OPEN-ANGLE Glaucoma?

Answer 5

1) MEASURE Intraocular Pressure
- GREATER than 21 mm Hg
(Normal Range 10 -21)

2) GONIOSCOPY
- Angle of ANTERIOR CHAMBER is open

3) OPHTHALMOSCOPY
- Check for GLAUCOMA CUPPING

• Examine the POSTERIOR POLE under a GREEN Light = REVEAL DEFECTS in FASICULAR Nerve Fibre

4) PERIMETRY = For Scotomas

Question 6

What is the DIFFERENTIAL DIAGNOSIS for PRIMARY OPEN-ANGLE Glaucoma?

Answer 6

• Ocular HT
• Low-Tension Glaucoma

Question 7

What is the GRADING SCALE for PRIMARY OPEN-ANGLE Glaucoma?

Answer 7

1) MILD = EARLY Visual Field DEFECTS

2) MODERATE
- PRESENCE of ARCUATE SCOTOMA
- THINNING of NEURORETINAL RIM

3) SEVERE
- EXTENSIVE Visual Field LOSS
- THINNING of NEURORETINAL RIM

4) END-STAGE
- SMALL RESIDUAL Visual Field remains
- VERY LITTLE Neuroretinal Rim remaining

Question 8

What is the TREATMENT for PRIMARY OPEN-ANGLE Glaucoma?

Answer 8

1) MEDICAL THERAPY
- Topical Beta-Blocker / Prostaglandin Analogue

2) LASER THERAPY
- Argon Laser Trabeculoplasty = LASERS the TRABECULAR MESHWORK in the IRIDOCORNEAL ANGLE, so it can ENHANCE its AQUEOUS OUTFLOW

3) SURGICAL THERAPY
a. Trabeculotomy = CREATING a FISTULA BTW Anterior Chamber AND Sub-Tenon Space TO ALLOW Aqueous Outflow

b. Artificial Shunts = Plastic Devices CONNECTING the Anterior Chamber TO the Sub-Tenon Space