How to use eye drops correctly and reduce systemic absorption

Correct eye-drop technique helps the medicine remain in contact with the eye, reduces the risk of contaminating the bottle and may limit the amount entering the bloodstream. Digital nasolacrimal occlusion is an additional step that can reduce systemic absorption. This may be particularly relevant during pregnancy and breastfeeding.

Before applying eye drops

Check that you have the correct bottle, are treating the correct eye and are using the medicine at the prescribed time. Read the label and Consumer Medicine Information for instructions about shaking, storage, contact lenses and the expiry period after opening.

Wash and dry your hands. Remove the cap without touching the bottle tip, and place the cap on a clean surface. The tip should not touch the eye, eyelids, eyelashes, fingers or any other surface because this can contaminate the contents.

Correct eye-drop technique

Sit or lie down with your head tilted back. If helpful, support the hand holding the bottle against your forehead.

1. Look upwards and gently pull down the lower eyelid to form a small pocket.

2. Hold the bottle above the eye without allowing the tip to touch the eye or surrounding tissues.

3. Place one drop into the lower-lid pocket. One drop is usually sufficient; additional drops commonly spill out or drain away.

4. Release the lower eyelid and close the eye gently. Do not squeeze the eyelids or blink repeatedly.

5. Perform digital nasolacrimal occlusion as described below.

6. Blot excess fluid from the skin with a clean tissue, replace the cap and wash your hands.

If you are uncertain whether the drop entered the eye, it is generally safe to try again immediately. If this happens often, or bottles run out earlier than expected, ask for a review of your technique.

Digital nasolacrimal occlusion

After applying the drop, keep the eye gently closed. Place a fingertip over the inner corner of the closed eyelids, beside the bridge of the nose, and apply light pressure for about one minute, or for the period advised for that medicine. The pressure should be directed over the tear-drainage opening, not onto the eyeball.

At the inner ends of the upper and lower eyelids are small openings called the lacrimal puncta. Tears and eye drops can pass through these openings into the canaliculi, lacrimal sac and nasolacrimal duct before reaching the nose. Medication absorbed through the nasal lining may then enter the bloodstream.

Digital nasolacrimal occlusion reduces drainage into the nose and can reduce systemic absorption. It does not completely prevent absorption. It may also lessen an unpleasant medicinal taste after some drops.

Eye drops during pregnancy and breastfeeding

Although eye drops are administered topically, some of the medication may enter the bloodstream. Because each drop contains a small dose, the amount reaching the systemic circulation is usually low in absolute terms. However, the proportion absorbed and its clinical significance vary between medicines, and systemic effects can occasionally occur. Low exposure does not mean that exposure is absent or that a medicine has been established as safe during pregnancy or breastfeeding.

Reliable pregnancy and breastfeeding safety data are limited for many eye drops. An absence of reported harm is not the same as evidence that a medicine is risk-free. The expected benefit of treatment should therefore outweigh any known or uncertain potential risk.

Women who are pregnant, planning pregnancy or breastfeeding should have every eye medication reviewed individually. Depending on the medicine and the clinical circumstances, options may include continuing treatment, changing the dose, substituting another treatment or stopping the medication.

The available evidence, its limitations, the potential consequences of treatment and non-treatment, and any reasonable alternatives should be explained clearly. Other treating practitioners may be involved where appropriate. Following this discussion, the decision about whether to use the medication ultimately rests with the woman.

If an eye drop is used, digital nasolacrimal occlusion can reduce systemic absorption, but it cannot eliminate exposure or make an otherwise unsuitable medicine safe.

Using more than one eye medication

Unless instructed otherwise, leave at least five minutes between different eye drops so that the second does not wash out the first. Perform nasolacrimal occlusion after each drop. If both drops and ointment are required, use the drops first and the ointment last, allowing the recommended interval.

Follow the specific storage, expiry, contact-lens and dosing instructions for each medicine.

Difficulty administering eye drops

Arthritis, tremor, reduced grip strength or difficulty tilting the head can make eye-drop administration difficult. Drop-assistance devices are available, although they do not fit every bottle. An eye-care professional or pharmacist can review the technique and help select a suitable device.

Brief stinging or blurred vision can occur with some drops. Seek advice if irritation persists or worsens, or if there is significant pain, redness, swelling, discharge or an unexpected change in vision. Sudden loss of vision requires urgent assessment.

Eye & Retina Specialists Sydney is located in Green Square/Waterloo. Patients who are uncertain about their eye-drop routine are encouraged to bring all current bottles to their appointment so the medicines, timing and administration technique can be reviewed.