Eye screening: GLP-1 RA based therapy (Guidelines)

Refer the following inpatients to retinal screeners:

nhsh.des@nhs.scot 

• Individuals disengaged from retinal screening for >12 months
• Pregnant (individuals with pre-existing / non gestational diabetes), at start of each trimester

Refer the following inpatients to ophthalmology clinic:

• Individuals already known to eye clinic who have disengaged / been lost to follow up
• Individuals known to eye clinic admitted in DKA
• Individuals known to eye clinic with new visual symptoms eg floaters, loss of vision

Non-urgent referrals

• Send a letter to appropriate consultant / associate specialist: Dr Shona Macleod / Dr Rhona Duggan / Dr Simon Hewick

Urgent referrals

• Contact emergency triage line: nhsh.eyecasualtyntch@nhs.scot 

Starting GLP-1 RA based therapy in individuals attending retinal screening

See quick reference guide

• If retinal screening is up to date and there is only mild / background retinopathy at most (ie not R3 or R4 grading) then individuals should be at low risk of developing significant worsening of retinopathy and the benefits of starting a GLP-1 RA treatments are likely to outweigh the risks.

Starting GLP-1 RA based therapy in outpatients attending ophthalmology clinic

See quick reference guide

Check when the last ophthalmology review occurred and whether the patient is being seen on time or overdue. 

• Some patients can be significantly overdue their review or be frequent non-attenders.
• If the review is overdue, then refer to the eye clinic for an assessment prior to starting treatment as retinopathy may have progressed during this time.
• Generally, a description of severe / very severe retinopathy is the most concerning.
• If there is proliferative retinopathy (PDR) then it should have been treated or be in the process of being treated.
• Pan retinal photocoagulation (laser) remains first line treatment for PDR.
• Patients with stable treated proliferative can start treatment if indicated.

For patients that are having intravitreal injections:

• Their retinopathy is controlled by this treatment.
• If they are having injections to only one eye, then the retinopathy level in the other eye is what is important.
• They should have an up-to-date review of the fellow eye prior to commencing GLP-1 RA based therapy.

In individuals with maculopathy not undergoing intravitreal injections:

• The benefits of tight glycaemic control may outweigh risks. 
• Commence GLP-1 RA therapy, if indicated, but advise patient of the possible risk of worsening retinopathy and to contact eye clinic if any new visuals symptoms.

In patients with longstanding suboptimal glycaemic control (>85mmol/mol) and more severe retinopathy:

• Consideration should be given to aiming for a slower reduction of blood glucose, albeit the evidence for benefit from this is limited. 
• It is difficult to define but aiming for an HbA1c reduction of <~17 mmol/mol at 3 months and <~21 mmol/mol at 6 months may be appropriate.

• DES: diabetes eye screening
• DKA: diabetic ketoacidosis
• EWDR: early worsening of diabetic retinopathy 
• GLP-1 RA: Glucagon-like peptide-1 receptor agonists
• HES: hospital eye service
• PDR: proliferative diabetic retinopathy