Caution: Darkly pigmented iris is more resistant to pupillary dilatation and caution should be exercised to avoid over dosage.
Antimuscarinics
Antimuscarinics dilate the pupil and relax the ciliary muscle resulting in mydriasis and cycloplegia. They can raise Intra Ocular Pressure (IOP) and should be used with caution in those patients susceptible to angle closure.
Atropine sulphate
- Eye drops 1% (£118.02 = 10ml)
- Single use preservative-free eye drops 1% (£17.13 = 20 unit dose (0.5ml))
- Eye ointment 1% (available from Martindale)
Notes
- Atropine has the longest activity, sometimes up to a week. Atropine has a tendency to cause hypersensitivity.
- Atropine ointment 1% is sometimes preferred for children aged under 5 years to produce cycloplegia prior to refraction, because the ointment formulation reduces systemic absorption.
Cyclopentolate hydrochloride
- Eye drops 1% (£8.08 = 5ml)
- Single use preservative-free eye drops 1% (£12.87 = 20 unit dose (0.5ml))
Notes
- Cyclopentolate activity lasts for up to 24 hours. It is included for corneal injuries, along with homatropine 2%, in order to reduce ciliary spasm and pain.
Homatropine
- Eye drops preservative-free 1% (unlicensed)
Tropicamide
- Single use preservative-free eye drops 0.5%, 1%
Sympathomimetics
Phenylephrine hydrochloride
- Single use preservative-free eye drops 2.5%, 10% (£13.08 = 2.5% x 20 unit dose (0.5ml))
Notes
- Phenylephrine hydrochloride is used for mydriasis in diagnostic procedures and pre-operative use.
- Phenylephrine 10% is more likely to cause cardiovascular side-effects and therefore it should not be used routinely.
Combination products
Mydrane
(Tropicamide with phenylephrine and lidocaine)
- Solution for injection ampoules 0.2mg/ml + 3.1mg/ml + 10mg/ml (0.6ml)
Notes
- Prescribe by brand (to aid identification where products contain multiple ingredients, or to prevent confusion where multiple brands contain similar ingredients).