Background Information

Definitions and Terms

Term	Definition	Notes
Ocular hypertension	Raised IOP (>21 mmHg) WITHOUT optic nerve damage / visual field loss	At risk of developing glaucoma
Glaucoma	Chronic optic nerve neuropathy characterised by optic disc cupping and visual-field defects Usually but NOT always associated with ocular hypertension	Umbrella term that includes: Normal tension glaucoma Chronic open-angle glaucoma Angle-closure glaucoma Secondary glaucoma
Normal tension glaucoma	Chronic optic nerve neuropathy with NORMAL IOP	Thought to involve vascular or structural susceptibility factors rather than IOP alone
Chronic open-angle glaucoma	Characterised by: Open anterior chamber (aka iridocorneal) angle Gradual IOP rise Progressive optic nerve neuropathy	The most common form of glaucoma Most cases present chronically
Angle-closure glaucoma	Characterised by raised IOP secondary to a closed anterior chamber angle	Most cases present acutely

 

Guidelines

Investigation and Diagnosis

Tests in Primary Care (before referral)

Offer ALL the following tests before referral:

• Central visual field assessment using automated perimetry
• IOP measurement with tonometry (e.g., measured with Goldmann aplanation tonometer)
• Optic nerve assessment and fundus examination with stereoscopic slit lamp biomicroscopy and OCT or optic nerve head image
• Peripheral anterior chamber configuration and depth assessment with gonioscopy / van Herick test / OCT

After the above tests, refer if ANY of the following:

• IOP ≥24 mmHg
• Visual field defect
• Optic nerve head damage 

Tests in Secondary Care

Offer ALL the following tests to diagnose COAG:

• Central visual field assessment using automated perimetry
• IOP measurement with Golmann-type applanation tonometry (slit lamp mounted)
• Optic nerve assessment and fundus examination with stereoscopic slit lamp biomicroscopy with pupil dilatation
• Peripheral anterior chamber configuration and depth assessment with gonioscopy
• Central corneal thickness measurement
  • A thin cornea underestimates true IOP, and a thick cornea overestimates IOP

Management

Ocular Hypertension – Management

Indications to treat: IOP ≥24 mmHg + at risk of visual impairment within their lifetime

• 1st line: 360° selective laser trabeculoplasty (SLT)
  • Consider a second attempt if the initial successful SLT has reduced over time

 

• 2nd line: prostaglandin analogue eye drops

 

• 3rd line: beta blocker eye drops

 

• 4th line: beta blocker / carbonic anhydrase inhibitor / sympathomimetic eye drops

 

COAG – Management

Indications to treat: IOP ≥24 mmHg OR at risk of visual impairment within their lifetime

Non-Advanced COAG – Management

• 1st line: 360° selective laser trabeculoplasty (SLT)
  • Consider a second attempt if the initial successful SLT has reduced over time

 

• 2nd line: prostaglandin analogue eye drops

• 3rd line: beta blocker / carbonic anhydrase inhibitor / sympathomimetic eye drops OR glaucoma surgery (e.g., surgical trabeculectomy) with mitomycin-C

 

• 4th line: cyclodiode laser treatment

 

Advanced COAG – Management

• Glaucoma surgery (e.g., surgical trabeculectomy), AND
• Pharmacological augmentation with mitomycin-C

Monitoring and Reassessment

At each assessment, offer the Goldmann applanation tonometry (slit lamp mounted)

If clinically indicated, also offer:

• Anterior segment slit lamp examination with van Herick peripheral anterior chamber depth assessment
• Repeat gonioscopy
• Repeat visual field testing with automated perimetry
• Repeat assessment of the optic nerve head

References

NICE Visual Aid – Management of Ocular Hypertension

NICE Visual Aid – Management of Chronic Open Angle Glaucoma

Original Guideline