6.1.8 Evaluates glaucoma risk factors to detect glaucoma and refer accordingly.

POAG

Risk factors:

Elevated IOP, increased age, black race, myopia, FH

POAG

Symptoms:

• Painless

• Peripheral vision loss

• Nocturnal vision problems

• Halos round lights

POAG

Signs:

• IOP > 24mmHg

  • Difference of >5mmHg

• Glaucomatous ONH

• Nasal step defects ➔ Arc defects

POAG

Management:

• Prostaglandin analogues Latanoprost, bimatoprost

  • Increase outflow of aqueous humour via uveoscleral route

• Beta-blockers Timolol

  • Reduce aqueous humour production

• Carbonic anhydrase inhibitors Acetazolamide

  • Reduce aqueous humour production

• Sympathomimetics Brimonidine, apraclonidine

  • Reduce aqueous humour production

• SLT Selective laster trabeculoplasty

  • Laser of the trabecular meshwork to improve aqueous drainage

• Trabeculectomy

  • Small hole created in sclera to increase aqueous humour to drainage

NICE recommends, before referral for further investigation and diagnosis of COAG and related conditions, people should be offered all the following tests:

• Central VF assessment using standard automated perimetry

• ON assessment + fundus examination using stereoscopic slit lamp biomicroscopy, and OCT or ONH image if available

• IOP measurement using GAT

• Peripheral AC configuration and depth assessments using gonioscopy or, if not available or patient prefers, the VH test or OCT.

AACG

Symptoms

• Severe eye pain

• Sudden vision loss (halos)

• Nausea and vomiting

• Frontal headaches

AACG

Signs:

• Severe red eye

• Fixed, dilated pupil

• Cornea oedema

• Very high IOP

AACG

Management:

• EMERGENCY REFERRAL

  • Hyperosmotic agents

    • Mannitol or Glycerin, rapid IOP change

  • Pilocarpine

    • Induce meiosis to open the angle

  • Laser Iridotomy

    • Creating iris hole so IOP flows into peripheral AC

• POAG treatment

What is NTG?

ONH damage and VF loss despite having IOP within normal range.

NTG

• Symptoms

• Signs

• Management

• Symptoms

  • POAG symptoms

• Signs

  • Same signs as POAG but with IOP < 24 mmHg

• Management

  • Same as POAG

Ocular Hypertension

Elevated IOP (>24mmHg) but no signs and symptoms indicating visual field loss or optic neuropathy

GLAUCOMATOUS Optic Nerve Head Appearance

• Increased CD ratio, especially vertical

• NRR thinning, notching, ISNT rule violation

• Flame-shaped disc haemorrhages

• Peripapillary atrophy: prominent ßzone

• CD asymmetry: >0.2

• Lamina cribrosa visible

• RNFL/GCC thinning

REFERRAL GUIDANCE

Emergency referral criteria:

If a patient’s IOP is measured by a community optometrist at 35 mmHg or over with symptoms of primary angle closure the patient should be referred to the Emergency Eye Clinic

REFERRAL GUIDANCE

Urgent referral criteria:

• Asymptomatic patients with an IOP of 35 mmHg or over measured by a community optometrist

• Pt’s with an IOP of 30mmHg or over following a repeat IOP reading via slit lamp GAT (Goldmann applanation tonometry) and full threshold/suprathreshold perimetry

REFERRAL GUIDANCE

Other referral criteria:

Patients with an IOP of 24 – 29 mmHg or over following a repeat IOP reading via slit lamp GAT (Goldmann applanation tonometry) + full threshold/suprathreshold perimetry

HOSPITAL TREATMENT

Glaucoma

• Selective Laser Trabeculoplasty (SLT)

• Laser Peripheral Iridotomy (LPI)

• Trabeculectomy

What is Selective Laser Trabeculoplasty (SLT)?

• Used mainly for open-angle glaucoma

• Enhances aqueous humour drainage through the trabecular meshwork

Selective Laser Trabeculoplasty (SLT)

Advantages vs limitations

Advantages

• Non-invasive, repeatable

• Minimal tissue damage

• Good option as primary therapy or adjunct to medications

Limitations

• Transient IOP spike (in first 24 hours)

• Mild inflammation

• Variable long-term success (usually 2–5 years of IOP control)

What is Laser Peripheral Iridotomy (LPI)?

• The standard laser treatment for ACG or angle-closure risk

• Creates a tiny hole in the peripheral iris, allowing aqueous humour to flow directly from the posterior to AC — bypassing pupillary block

• Equalises pressure between posterior and anterior chambers, flattening the iris and opening the drainage angle.

Laser Peripheral Iridotomy (LPI)

Advantages vs limitations

Advantages

• Quick, outpatient, sight-saving in acute cases

• Prevents recurrence of angle closure

Limitations

• Transient IOP rise (controlled with drops)

• Inflammation, glare, ghost images

• Rarely closure of the iridotomy requiring repeat procedure

What is a trabeculotomy?

Creates a new drainage channel for aqueous humour from the AC to a subconjunctival bleb.

Aqueous humour filters from the anterior chamber under a scleral flap into a filtering bleb, where it is absorbed by conjunctival and episcleral tissues — lowering IOP.

Trabeculectomy

Advantages vs limitations

Advantages

• Signif + durable IOP reduction

• Can reduce or eliminate need for medications

Limitations

• Early: Hypotony, shallow anterior chamber, choroidal effusion, bleb leak

• Late: Bleb scarring/failure, blebitis, endophthalmitis

• Req’s long-term follow-up and bleb care