Medicated ophthalmic ointment is a semi-solid preparation designed to deliver active ingredients to the eye’s surface. Unlike liquid eye drops that are quickly washed away by natural tear production, the thicker consistency of an ointment allows the medication to remain in contact with the eye for a significantly longer duration. This extended contact time benefits treatments for conditions like severe dry eye, bacterial infections, or corneal abrasions that require continuous medication exposure. Ointments are frequently prescribed for use at night, ensuring the medication works effectively while the patient sleeps.
Defining the Conjunctival Sac
The conjunctival sac is the anatomical space where ophthalmic ointment must be placed for proper absorption and effectiveness. This sac is the pocket formed between the inner surface of the eyelid and the outer surface of the eyeball. The conjunctiva, a thin mucous membrane, lines the posterior of the eyelids and folds over to cover the white part of the eye, known as the sclera.
The fold where the conjunctiva transitions from the eyelid to the eyeball creates the loose space of the sac, sometimes referred to as the cul-de-sac or fornix. Medication is directed into this lower pocket, rather than directly onto the cornea, to prevent damage to the eye’s sensitive central surface. Placing the ointment in this protected area allows eyelid movements to gently distribute the medication across the eye without causing irritation.
Detailed Application Technique
Proper administration of ophthalmic ointment begins with preparation to ensure hygiene and patient comfort. Before touching the ointment tube or the eye, hands must be thoroughly washed with soap and water to prevent the introduction of bacteria. Holding the tube for a minute or two can help slightly warm the medication, allowing it to flow more smoothly during application.
The patient should be positioned comfortably, either sitting with the head tilted back or lying down, with their gaze directed upward toward the ceiling. This positioning allows gravity to help keep the ointment in place and provides the clearest access to the lower eyelid. Application involves creating a pocket by gently pulling the lower eyelid down and away from the eye using a clean finger or thumb.
With the lower lid pulled down, the tip of the ointment tube is held close to the exposed conjunctival sac, taking care to never let the tip make contact with the eye, lashes, or surrounding skin. A ribbon of ointment, typically measuring about one half-inch (or approximately 1 cm) in length, is squeezed directly into the pocket of the lower conjunctival sac. Applying the ointment along the inside of the lower lid ensures the medication is placed in the proper anatomical location.
After the prescribed amount of ointment has been applied, the tube is withdrawn, and the lower eyelid is released. The patient should then close their eye gently for one to two minutes, or blink several times, which aids in distributing the ointment evenly across the ocular surface. Any excess ointment that may have squeezed out should be carefully wiped away with a clean tissue.
Expected Side Effects and Precautions
The most common side effect following ophthalmic ointment application is temporary blurred vision, which occurs because the thick base of the ointment interferes with the eye’s ability to focus light. This effect typically lasts for 5 to 15 minutes, but the duration varies depending on the product and the amount used. Patients should avoid driving or operating machinery until their vision has fully cleared.
Preventing contamination requires absolute adherence, as the eyes are highly susceptible to infection. The tip of the ointment tube must never touch the eye, eyelid, or any other surface, as this can introduce bacteria into the medication, potentially leading to a severe eye infection. If the tip accidentally makes contact with any surface, the tube must be considered contaminated and discarded.
Ophthalmic ointments should only be used by the person for whom they were prescribed and should never be shared. A standard hygiene protocol is to discard any remaining ointment four weeks after the tube is first opened, regardless of the expiration date, because of the risk of bacterial growth. If a patient is using both eye drops and an ointment, the drops should always be applied first, with a waiting period of several minutes before the ointment is introduced, to ensure the liquid medication is absorbed effectively.