Skip to main content
Glaucoma referral criteria

Glaucoma referral criteria

Best Practice Guidance


Glaucoma is a leading cause of irreversible blindness worldwide. In England, new glaucoma cases are detected in primary care via routine optometric sight tests. These are then referred to HES for monitoring and treatment. However, these sight tests have accuracy limitations for detecting or ruling out glaucoma and glaucoma-related conditions, resulting in a high percentage of false positive referrals to secondary care (up to 40% in certain cases). This causes unnecessary anxiety for patients who do not need referral and potential delays for those who do, risking avoidable blindness.


This guidance applies to those 18 years and over.

Before referral for further investigation and diagnosis of glaucoma and related conditions, offer all of the following tests, which are separate from a sight test:

  • Central visual field assessment using standard automated perimetry (full threshold or supra-threshold)
  • Optic nerve assessment and fundus examination using stereoscopic slit lamp biomicroscopy (with pupil dilatation if necessary) and optical coherence tomography (OCT) or optic nerve head image if available.
  • Intraocular pressure (IOP) measurement using Goldmann-type applanation tonometry
  • Peripheral anterior chamber configuration and depth assessments or, if not available, or the person prefers, the van Herick test or Optical Coherence Tomography (OCT).

Before deciding to refer, consider repeating visual field assessment and IOP measurement on another occasion (repeat measures) to confirm a visual field defect or IOP of 24mmHg or more, unless clinical circumstances indicate urgent or emergency referral is needed.

Refer for further secondary care investigation and diagnosis of glaucoma and related conditions, after considering repeat measures, if:

  • There is optic nerve head damage on stereoscopic slit lamp biomicroscopy


  • There is a visual field defect consistent with glaucoma


  • IOP is 24 mmHg or more using Goldmann-type applanation tonometry.

Please note that this guidance is intended as a standard threshold for access. However, if you/ your patient falls outside of these criteria, the option to apply for an Individual Funding Request is still available to you.

Rationale for recommendation

Ophthalmology is the busiest outpatient speciality in UK secondary care, with demand increasingly surpassing capacity. Monitoring and treating patients with glaucoma accounts for 20% of current ophthalmology outpatient activity. Over the next 10 (20) years glaucoma cases are predicted to rise exponentially; confirmed glaucoma diagnoses by 22% (44%), suspected glaucoma cases by 10% (18%) and OHT by 9% (16%).

Currently, new glaucoma cases are referred via routine optometric sight tests. However, evidence suggests there is poor sensitivity and specificity for detecting glaucoma and glaucoma-related conditions, resulting in a high percentage of false positive referrals to secondary care (up to 40% in certain cases). A variety of enhanced primary eye care services and referral filtering models have been developed to improve the accuracy of referrals. Referral filtering models range from 1) ‘repeat measurement’ schemes in which IOP measurement or visual field assessments, or both, are repeated at a separate visit by the referring optometrist to 2) enhanced case finding (more extensive tests than IOPmeasurements) undertaken by another optometrist, to 3) referral refinement, in which  another optometrist who is specifically trained undertakes a more comprehensive set of tests defined by NICE NG81.

Patient information

Currently, glaucoma (a common eye condition where the optic nerve, which connects the eye to the brain, becomes damaged, leading to sight loss) is usually found in people during routine sight tests by optometrists (opticians). The optometrist will then refer them to a hospital. However, the accuracy of sight tests for ruling out glaucoma is poor. This can create unnecessary anxiety for patients and unwarranted referrals. Evidence shows that additional clinical assessment by optometrists will improve the accuracy of referrals.

The EBI programme proposes that the pathway for the referral of glaucoma and related conditions (such as ocular hypertension [OHT] which is raised eye pressure without optic nerve damage) to a hospital eye service is consistent across England to include additional clinical assessments and repeat measurements performed by optometrists, as recommended by NICE NG81 These services are outside of the sight test and need to be locally commissioned.

We recommend using the BRAN principles (Benfits, Risks, Alternatives and do Nothing) when speaking with patients about this.

Further information on patient involvement in EBI can be found on the EBI for patients section.




Code script

WHEN ( APCS.Der_Diagnosis_All LIKE '%H40[012345689]%' 
OR APCS.Der_Diagnosis_All LIKE '%H42[08]%' 
OR APCS.Der_Diagnosis_All LIKE '%H445%’
OR APCS.Der_Diagnosis_All LIKE '%P153%’
OR APCS.Der_Diagnosis_All LIKE '%Q150%’)
AND (NOT ( APCS.Der_Diagnosis_All LIKE '%H46%' 
OR APCS.Der_Diagnosis_All LIKE '%H470%’ )
OR APCS.Der_Diagnosis_All IS NULL )
AND APCS.Admission_Method NOT LIKE '2%’
THEN '3D_Glaucoma_Referral’
WHEN (OPA.Der_Diagnosis_All LIKE '%H40[012345689]%' 
OR OPA.Der_Diagnosis_All LIKE '%H42[08]%' 
OR OPA.Der_Diagnosis_All LIKE '%H445%’
OR OPA.Der_Diagnosis_All LIKE '%P153%’
OR OPA.Der_Diagnosis_All LIKE '%Q150%’ )
AND (NOT ( OPA.Der_Diagnosis_All LIKE '%H46%' 
OR OPA.Der_Diagnosis_All LIKE '%H470%')
OR OPA.Der_Diagnosis_All IS NULL )
THEN '3D_Glaucoma_Referral'

Code Definitions

Diagnosis codes (ICD)

H400 Glaucoma suspect
H401 Primary open-angle glaucoma
H402 Primary angle-closure glaucoma
H403 Glaucoma secondary to eye trauma
H404 Glaucoma secondary to eye inflammation
H405 Glaucoma secondary to other eye disorders
H406 Glaucoma secondary to drugs
H408 Other glaucoma
H409 Glaucoma, unspecified
H420 Glaucoma in endocrine, nutritional and metabolic diseases
H428 Glaucoma in other diseases classified elsewhere
H445 Degenerated conditions of globe (absolute glaucoma is classified to this code)
P153 Birth injury to eye (traumatic glaucoma due to birth injury is classified to this code)
Q150 Congenital glaucoma
H46X Optic neuritis
H470 Disorders of optic nerve, not elsewhere classified

Procedure codes (OPCS)

Potential exclusions (indicating treatment rather than referral)
C52.1 Deep sclerectomy with spacer
C52.2 Deep sclerectomy without spacer
C60.1 Trabeculectomy
C60.5 Insertion of tube into anterior chamber of eye to assist drainage of aqueous humour
C60.6 Viscocanulostomy
C60.8 Other specified filtering operations on iris
C60.9 Unspecified filtering operations on iris
C61.1 Laser trabeculoplasty
C61.2 Trabeculotomy
C61.3 Goniotomy
C61.4 Goniopuncture
C61.5 Viscogonioplasty
C61.8 Other specified other operations on trabecular meshwork of eye
C61.9 Unspecified other operations on trabecular meshwork of eye
C62.1 Iridosclerotomy
C62.2 Surgical iridotomy
C62.3 Laser iridotomy
C62.8 Other specified incision of iris
C62.9 Unspecified incision of iris

Additional Exclusions
apcs.der_diagnosis_all not like '%C[0-9][0-9]%' and 
apcs.der_diagnosis_all not like '%D0%' and 
apcs.der_diagnosis_all not like '%D3[789]%' and
apcs.der_diagnosis_all not like '%D4[012345678]%’

This code captures code in the ranges C00-C99, D00-D09 and D37-D48.
Age range: the codes use the following age ranges 0-18 for children and 19-120
for adults.
— Private Appointment Exclusion
AND apcs.Administrative_Category<>’02’


  1. NHS England. Elective Care High Impact Interventions: Ophthalmology specification. 2018
  2. Royal College of Ophthalmologists. The Way Forward report: Glaucoma. 2017
  3. NHS England. Getting it Right First Time: Ophthalmology Speciality Report. 2019
  4. Royal College of Ophthalmologists. Glaucoma Management Plans during Recovery phase of Covid-19. 2020
  5. Foot B, MacEwen C. Surveillance of sight loss due to delay in ophthalmic treatment or review: frequency, cause and outcome. Eye (Lond). 2017 May;31(5):771-775. doi: 10.1038/eye.2017.1. Epub 2017 Jan 27. PMID: 28128796; PMCID: PMC5437335
  6. NICE. Glaucoma: diagnosis and management [NG81]. 2017
  7. Henson DB, Spencer AF, Harper R, Cadman EJ. Community refinement of glaucoma referrals. Eye. 2003; 17(1):21-26
  8. Patrick J G Gunn et al (2018) Clinical effectiveness of the Manchester Glaucoma Enhanced Referral Scheme. British Journal of Ophthalmology: 1–6
  9. Healthcare Safety Investigation Branch. Lack of timely monitoring of patients with glaucoma. 2020
  10. National Patient Safety Agency. Rapid Response Report: Preventing delay to follow up for patients with glaucoma. 2009
  11. NHS England. Transforming elective care services: ophthalmology. 2019. p33-38.
  12. Mathew, R.G., Beddow, C.J., Raison, H. et al. Project Panopia: cost-effective model for glaucoma referral refinement from community optometrists without the need for repeat testing. Eye 35, 1056–1060 (2021)
  13. Local Optical Committee Support Unit. Clinical Pathways
  14. NHS England and Improvement Eye Care Hub. National Eye Care Recovery and Transformation Programme guidance.
  15. Mackenzie S, Schmermer C, Charnley A, et al. SDOCT Imaging to Identify Macular Pathology in Patients Diagnosed with Diabetic Maculopathy by a Digital Photographic Retinal Screening Programme. PloS one 2011;6:e14811.

How up to date is this information?

Last revised December 2023


December 2023 - Coding updated