Fluorescein with lidocaine

How it works

Fluorescein stains areas of de-epithelialised cornea and conjunctiva and fluoresces under blue light to reveal epithelial defects, while lidocaine produces rapid surface anaesthesia by blocking neuronal sodium channels.

Prescribing in practice

• This is for diagnostic use only and must never be supplied for repeated self-administration, as continued topical anaesthesia causes corneal epithelial toxicity, delayed healing and ulceration.
• The anaesthetised eye loses its protective blink and corneal sensation, so it should be shielded from injury until sensation returns.
• Fluorescein can permanently stain soft contact lenses, which should be removed beforehand.

Monitoring

No laboratory monitoring is required; the clinician observes the staining pattern under cobalt-blue light and confirms adequate but transient anaesthesia during the procedure.

Counselling the patient

• Your eye will be numb for a short while, so avoid rubbing or touching it until normal feeling returns.
• The dye may briefly tint your tears yellow-orange.
• Leave contact lenses out until advised it is safe to reinsert them.

Evidence & guidelines

Combined fluorescein and local anaesthetic drops are standard adjuncts for tonometry and minor ocular procedures in routine ophthalmic and emergency practice.