Guidance

Use of mydriatic eye drops in the NHS diabetic eye screening programme

Updated 12 May 2025

1. Use of mydriatic eye drops in the NHS diabetic eye screening programme

Diabetic eye screening (DES) requires the pupil of the eye to be as dilated (wide) as possible to facilitate retinal screening. This is achieved by instilling medication (drops) into the eye. This is known as mydriasis.

2. Informing individuals attending screening

The DES service should inform individuals before they attend their screening appointments that:

• eye drops will be used (unless contraindicated)
• eye drops may affect vision
• it will not be safe to drive home for at least 4 hours after the appointment because of these side effects

In line with standard healthcare practice, screeners should make sure that individuals attending screening are informed of and understand the potential adverse side effects of the eye drops and the actions to be taken if they occur.

Screeners should give individuals written information on who to contact or what to do in case they need further advice, or if they experience any unexpected side effects. An emergency, out of hours process for medical advice should be provided in writing. This information should also be added to the service’s out of hours answerphone message.

Further guidance is available for people with diabetes who drive to appointments.

3. Individuals unable to have eye drops

If an individual is unable to have eye drops instilled due to a pre-existing condition or contraindication, for example acute angle glaucoma, allergy to eye drops, or anxiety disorder, photographs can be attempted without mydriasis. The reason for not instilling drops must be included within the individuals notes on the DES software.

The individual should be informed that if the screener cannot assess the images (unable to view the back of the eye) they will be referred for another appointment using different equipment called Slit Lamp Bio-microscopy.

4. Individuals unwilling to have eye drops

If an individual is unwilling to have drops instilled before screening, the screener should first:

• explain that screening requires mydriasis to enable the best possible view of the retina
• encourage the individual to discuss their concerns with their diabetes care team or DES service
• book a further appointment no more than 2 months after the initial appointment, to allow time for a discussion

If the individual still does not consent to dilation, the service should inform them of:

• their choice to opt out of screening via completion of the opt out process
• the risks associated with opting out
• their ability to opt back in at any time by contacting the DES service

If the local DES service does not receive an opt out form it should continue to invite the individual for routine digital screening. By giving the advice outlined above, the service has provided reasonable opportunity for the individual to make an informed decision about declining drops and eye screening.

The GP should be notified of any person’s decision to opt out using the programme opt out process or where screening has been declined (not opted out) due to refusal of drops.

Find further information regarding opt out and postponement in the guidance on cohort management in diabetic eye screening.

5. Mydriatic agents

To improve the quality of captured images, a mydriatic agent such as tropicamide 0.5% or 1.0% is usually instilled before retinal photography. In some cases, phenylephrine 2.5% may also be required.

6. Purchase and administration of tropicamide and phenylephrine 2.5%

Tropicamide 0.5% and 1.0% are a prescription-only medicine (POM).

The wholesale supply of POMs is restricted to specified classes of healthcare professionals and organisations such as NHS trusts, doctors, pharmacists and optometrists.

Find more information on rules for the sale, supply and administration of medicines.

Phenylephrine 2.5% is a Pharmacy (P) medicine. P medicines may be obtained by anyone for administration in the course of business provided they are to be used within their licensed indications.

7. Who can administer eye drops as part of the NHS Diabetic Eye Screening Programme?

The following guidance on who can administer eye drops as part of the NHS DES programme was most recently reviewed by the Medicines & Regulatory products Regulatory Agency (MHRA) in 2021 to ensure current legislation is complied with.

Find more information about the MHRA.

7.1 Retinal Screeners

A retinal screener within the DES programme is as an individual performing the competencies required for the identification of sight-threatening diabetic retinopathy in a screening programme for diabetic retinopathy within the NHS. This includes:

• visual acuity measurement
• mydriatic drop instillation
• data collection (demography and diabetes care)
• photography and retinopathy grading

Individuals performing these roles may include optometrists, health care assistants, medical photographers, trained nurses, GPs, diabetologists, ophthalmologists and retinal screeners/graders who are employed within the NHS or the independent sector, working within a commissioned NHS DESP service.

7.2 Administration of eye drops

The MHRA advises that the administration of non-parenteral drugs in the circumstances described above for the purposes of diabetic retinal screening is not in breach of the Medicines Act and no amendment to medicines legislation is required. ‘Non-parenteral’ means any method of administering a therapeutic substance or medication that does not involve puncturing a patient’s skin or any active delivery through the skin via use of a device.

The MHRA has confirmed that:

• retinal screeners can legally instil guttae tropicamide 0.5%, and guttae tropicamide 1.0% (prescription only medicines - there is no requirement for a Patient Group Direction in this situation)
• the same advice applies to phenylephrine 2.5% (a pharmacy medicine)

This applies throughout the UK. However, if in the future there was a change to extend the role of retinal screeners further to include the administration of a parenteral medicine, this may require a change in the law.

8. Retinal Screener employed by NHS providers

Legal advice provided by the MHRA confirms retinal screeners working in the NHS DESP, employed by NHS bodies such as foundation trusts, can access eye drops obtained by those bodies for administration in the course of their business. No prescription, patient group direction (PGD), patient specific direction (PSD) or other order is required.

The MHRA suggests that agency staff working under close supervision within a trust undertaking retinal screening in a DES service and covered by the trust’s insurance may be in a similar position. However, advice from the Trust’s legal team should be sought first.

Trusts subcontracting the retinal screening element of the DESP pathway to another provider (that is not part of their organisation) should be aware that unless they have a wholesale dealer’s licence, they cannot legally supply stocks of POM and P medicines to that subcontracted provider.

Trusts subcontracting to independent sector healthcare providers that employ registered health professionals (such as nurses and optometrists) to administer eyedrops as part of the diabetic retinal screening programme, could enter into an arrangement to do this under a Patient Group Direction (PGD). The PGD would need to be authorised by the trust concerned. In these circumstances, the company can obtain wholesale supplies of the medicines to be administered under the PGD.

Registered health professional status does not apply to retinal screeners who have obtained the Health Screener Diploma or City and Guilds Qualification and have no other professionally registered health qualification.

9. Optometrist-based providers

An optometrist may lawfully obtain stocks of tropicamide as well as P medicines for administration in the course of their business. The optometrist could allow employees to access these medicines for administration only, for example, in retinal screening procedures. There may be a question as to whether this is appropriate in terms of the optometrist’s professional practice, but this will be a matter for the professional body, the General Optical Council.

For more information, see guidance developed by the College of Optometrists and the General Optical Council.

If the optometrist is not instilling the drops themselves, they should make sure they are on the premises while it is being done so they can intervene if necessary.

10. Independent sector healthcare providers

There are no other specific provisions in medicines legislation for independent companies providing diabetic eye screening and grading services that are not registered to obtain wholesale supplies of POMs. However, doctors, pharmacists and optometrists employed by an independent company are entitled to order and receive wholesale supplies of tropicamide. Legal advice obtained by the MHRA indicates that these supplies can be distributed to screeners employed within the same company provided the healthcare professional purchasing the drops retains responsibility for the screeners and the medicines. Legal and professional practice (GOC) advice should be sought in these scenarios.

For more information, see the Royal College of Ophthalmologists guidance on eye drop instillation by unregistered health care professionals.

11. Training and competencies required for administering drops within the NHS DES programme

All staff should undertake and pass the modules in the Health Screening Diploma relevant to their role before administering drops unsupervised. This provides assurance that individuals have appropriate training and competencies required to an agreed national standard. A training and competency record must be maintained for every individual who is required to administer drops.

The following guidance documents set out good practice to follow when delegating the medicines to a non-registered healthcare professional:

• Care Quality Commission guidance on delegating medicines administration
• Royal College of Nursing guidance on accountability and delegation

Observations by a clinical lead or delegated individual should take place in line with guidance to make sure the screener is still competent. The observations should be formally recorded and available for audit.

DES provider infection, prevention and control (IPC) measures should be followed, and mandatory IPC training should be accessed as required by the trust.

Audits on ungradable rates by screeners should be undertaken in line with the audit schedule to highlight and address high ungradable rates and dilation practices. For more information, see page 31 of Diabetic eye screening: assuring the quality of grading.

12. Standard operating procedures

Clear, written processes and protocols regarding the instillation of drops and mydriasis should be maintained within the DES screening programme in a place easily accessed by the screeners, including where staff are working remotely.

This should include:

• what to say to the individual about the drops and their instillation
• IPC information
• any exclusion or contraindication criteria^{[footnote 1]}
• correct dosage^{[footnote 1]}
• information about adverse reactions^{[footnote 1]}
• details regarding how the user can seek further advice if needed, including access to medical advice in an emergency
• what to do if the individual attending for their screening appointment refuses/is unsuitable for drops or has driven^{[footnote 2]}
• who the screener can contact if they are unsure whether drops can be administered
• how to document the treatment episode in the screening encounter
• what to do and who to contact if something goes wrong

13. References

1. Electronic medicines compendium (emc): the Patient Information Leaflet (PIL) for Minims Tropicamide 1% w/v, eye drop solution and the Summary of Product Characteristics (SmPC) for Minims Phenylephrine Hydrochloride 2.5%w/v eye drops solution ↩ ↩² ↩³

2. Diabetic eye screening: patients who drive to appointments ↩