You must consider the cautions and contraindications for each drug you use in practice.¹⁵²

There is potential for interaction with some systemic drugs. For example, phenylephrine may interact with systemically administered monoamine-oxidase inhibitors and anti-hypertensive drugs.

If pupils are likely to be dilated, tell patients when they make an appointment that they might not be able to drive after the examination. Suggest that they bring sunglasses with them. 

When you use drugs that dilate the pupil, you should consider whether to: 

1. check the depth of the anterior chamber, for example using the van Herick technique, for the possibility of angle closure
2. measure intra-ocular pressures as appropriate, for example before and/or after dilation.

The NHS Diabetic Eye Screening Programme does not consider these checks necessary when using tropicamide alone.

You should check corneal integrity, if appropriate.

You should ask the patient if they:

1. have experienced adverse reactions to eye drops in the past
2. have a history of drug-induced adverse incidents
3. have any relevant medical conditions
4. take any systemic drugs.

You should check for possible interactions with any systemic medication that the patient may be taking.

You should check: 

1. that you are administering the correct drug and dosage
2. the expiry date.

You should record all drugs used, including the batch number and expiry date, on the patient record.

You may keep a logbook of which drugs are used on each patient. This will help you if you need to recall patients.

You should explain to the patient: 

1. why you are instilling the drug
2. what effects the drops might have
3. how long the effects might last
4. the side effects they might experience
5. if you are dilating their pupils, that they might not be able to drive and must not undertake any activity which is not advised after dilation, and for how long
6. if you are using anaesthetic drops, that they should avoid wearing contact lenses for an appropriate period of time after anaesthesia
7. what to do if they experience an adverse reaction.

You may give the patient an information sheet.¹⁵³

You should tell the patient to attend the local Accident and Emergency department if you are not available to deal with any emergency or adverse reaction that may arise following the instillation of the drug. 

You should inform the patient’s GP of any suspected adverse reaction. See also paragraph A458.

There is no legal restriction on who can instil eye drops to a person. The law only restricts supply of the drops. 

You are responsible for the instillation of eye drops and so, if you decide to delegate this to another member of staff, you must be on the premises whilst this is being done so you can intervene if necessary.¹⁵⁴ You are responsible for the management of the patient and the work of the person to whom you have delegated the procedure. See section on Working with colleagues.