Administration of drugs to the eye

1. Eye drops and eye ointments are instilled into the pocket formed by gently pulling down the lower eyelid. For eye drops, one drop is all that is needed as long as instillation is successful. For eye ointments, a small amount is applied similarly; the ointment melts rapidly and blinking helps to spread it.

2. When two or more different drops are required at the same time of day, the patient should leave an interval of 5 minutes between drops to avoid dilution and overflow. Also to use ointment preparations 5 minutes after drops.

3. Certain preparations included within this chapter of the formulary are unlicensed and marked with *. These products will be ordered specially and are not stocked; therefore a delay in obtaining stocks may be incurred. These 'specials' may be supplied when clinical need for the individual patient demands, given no commercial alternative is available. Specials are often very costly.

Administration aids: Eye drop dispensers are available to aid the instillation of eye drops especially amongst the elderly, visually impaired, arthritic, or otherwise physically limited patients. They can be purchased from most community pharmacies or prescribed on FP10 prescription. Please refer to the Drug Tariff for details - Appliances: Eye Drops Dispensers.

Preservatives and sensitisers:

1. Long-term administration of preservative containing eye drops may cause ocular irritation.

2. RCHT Eye Unit offer the following recommendations for when to use preservative free treatments:

• the patient has a proven allergy to the preservative
• frequent use of the drops - six or more time a day (long-term use)
• the patient is wearing a soft contact lens or bandage lens at the time of instillation, on specialist advice
• after a corneal transplant in selected cases, depending on indication, and in cases where the cornea is compromised, on specialist advice

3. All Minims^® and other single use products are preservative free.

1. Topical ophthalmic steroids placed in descending order of potency:

• prednisolone acetate 1% (most potent)

The severity of the inflammation determines the choice of steroid.

2. Topical steroids should not be used for undiagnosed red eye. If red eye is due to herpes simplex, corticosteroids will aggravate this condition possibly leading to loss of vision or even loss of the eye.

3. Steroid eye drops can raise intra-ocular pressure (IOP) and therefore precipitate glaucoma in patients predisposed to primary open angle glaucoma. Evidence suggests that fluorometholone is less likely to raise IOP though this may be due to reduced penetration of the cornea.

4. A steroid cataract may follow prolonged use with topical steroids

5. Steroid-antibiotic ophthalmic combinations are not recommended for routine use, other than for short-term post-op treatment.