Guidance

Diabetic eye screening: surveillance pathways

Updated 16 October 2024

This guidance describes the management of the surveillance pathways within NHS diabetic eye screening (DES) services.

The surveillance pathways manage individuals with diabetes between routine digital screening (RDS) and referral to a hospital eye service (HES). Surveillance clinics are managed by the screening service and can take place in a range of venues such as health centres, optometrist practices and ophthalmology departments.

Surveillance pathway options

Digital surveillance

Digital surveillance (DS) allows more frequent screening of those people who may be at increased risk of developing diabetic retinopathy but have not reached the threshold to be referred into HES.

Slit lamp biomicroscopy surveillance

Slit lamp biomicroscopy surveillance (SLBS) is an examination technique used when adequate retinal examination cannot be obtained using digital photography. People with diabetes may be referred for annual slit lamp biomicroscopy (SLB) appointments for as long as gradable retinal images continue to be unobtainable.

Pregnancy surveillance

Pregnant women require photographic screening that is more frequent and follows the NICE guideline recall periods. The pregnancy pathway will be a separate surveillance category which allows an individual to be moved from RDS on notification of the pregnancy.

Women will remain in the pregnancy pathway until they are recorded in the software as delivered, no longer pregnant or have been referred to HES.

Pathway overviews

An overview of each of the surveillance pathways is available.

Key elements of the surveillance pathways

Services should organise surveillance clinics to meet local need. The software should allow clinics to be booked solely for RDS, surveillance or a combination of both.

There should be:

• streamlined management capabilities across the 3 separate surveillance pathways
• independent call and recall managed by the screening service
• the ability to refer any individual from a surveillance pathway directly to HES
• recall periods of 1, 3, 6, 9 and 12 months in DS to allow for ongoing review of grade outcomes R1M1, R2M0, R2M1, R3s (with or without optical coherence tomography (OCT) images)
• 12 months recall in SLBS to allow for ongoing review of ungradable and unobtainable outcomes
• the ability to invite pregnant women for re-screening throughout the pregnancy in line with NICE guidelines
• the facility to attach baseline retinal images for stable treated R3 to an individual’s record on discharge from HES
• failsafe functionality within the software that provides alerts and triggers to enable safe management of people within the surveillance pathways
• the ability to record visual acuities at all surveillance encounters

Optical coherence tomography (OCT) in surveillance clinics

OCT is not currently included in NHS England commissioned DES services and any provision of OCT assessments will need to be commissioned separately.

Services may link to OCT for the assessment of maculopathy as part of their surveillance clinics with the outcome recorded within the screening software using the features-based grading (FBG) form.

Read the national best practice guidance for OCT for more information.

Staffing a surveillance clinic

The clinical lead is clinically responsible for all surveillance clinic activity, including the training and supervision of screening and grading staff. Responsibility can be delegated to a referral outcome grader (ROG) or senior grader.

Staff running surveillance clinics should be line-managed within the screening service.

There is separate documentation available for SLB examiner competencies.

Workforce planning for surveillance clinics should be included in the service’s standard operating procedures (SOP).

Status of individuals in surveillance clinics

People with diabetes who are seen in surveillance clinics are included within the eligible population but suspended from receiving routine digital screening invitations until they are discharged back to RDS.

Further information on eligibility is included in the cohort management guidance.

Referral and discharge

Referring into a surveillance clinic

The ROG will have the option to refer individuals into a surveillance clinic.

The following outcome grades may be referred to a surveillance clinic:

Digital surveillance

Outcome grades should be:

• R3 stable (R3s) following discharge from HES
• R1M1
• R2M0
• R2M1

Maculopathy can be referred to HES or DS depending on whether OCT is used.

Slit lamp biomicroscopy surveillance

Outcome grades should be ungradeable or unobtainable images.

SLBS should not be used to review maculopathy.

Pregnancy

Outcome grades should be pregnant women who are R0M0/R1M0.

All other grade outcomes should be referred to HES.

Services should not request their software provider configure any additional recall periods outside of the mandated recall periods of 3, 6, 9 or 12 months.

The following recall periods should be used within each surveillance category:

• digital surveillance - 3, 6, 9 and 12 months
• SLB surveillance - 12 months
• pregnancy surveillance - 16 to 20 weeks gestation and 28 weeks gestation, plus the option for a manual date input

Referral from surveillance to HES

People who are screen positive following a surveillance appointment should be referred to HES according to national referral timescales.

For urgent referrals (R3AM0/R3AM1), the time between RDS/DS or SLBS event and issuing the urgent referral to HES should be:

• acceptable: ≥95% within 2 weeks
• achievable: ≥98% within 2 weeks

For routine referrals (R2M0/R2M1/R1M1), the time between RDS/DS or SLBS event and issuing the urgent referral to HES should be:

• acceptable: ≥90% within 3 weeks
• achievable: ≥95% within 3 weeks

Discharge from HES into a surveillance clinic

Local agreement between the service and HES should be developed so patients are discharged back to a surveillance clinic with a specified recall period of 3, 6, 9 or 12 months once they are considered stable.

Stable treated retinopathy (R3s)

People who are discharged from HES with a grade of R3s should be managed in the digital surveillance pathway.

A benchmark image set must be taken either within HES or the screening service and graded as soon as possible (and no longer than 3 months from the discharge decision) by an ophthalmologist or ROG. The benchmark image set must be attached to the individuals screening record for future comparison during the next digital surveillance appointment.

Benchmark images are only needed for R3s grades.

Discharge from a surveillance clinic to routine digital screening

Individuals who are within DS may be returned to RDS when they have a screen negative outcome (R0M0, R1M0). Individuals who are within SLBS may be returned to RDS when their reason for being in SLBS has resolved (for example, cataract removal).

The software should retain the latest set of images and grade outcome on discharge from surveillance.

Non-diabetic retinopathy

People with non-diabetic retinopathy pathology should not be screened within a surveillance clinic and should remain eligible for routine digital screening.

Services should develop a separate SOP that outlines the referral process for any incidental findings and follows section 2 of the managing referrals to hospital services guidance