OPHTHALMOLOGY

Q:

My eye doctor just started me on two different glaucoma drops to control my eye pressure (IOP). I was told to wait five minutes between drops. Why is this wait time necessary? Do the drops have any side effects? A:

For those diagnosed with glaucoma, prescription eye drops is often the initial plan of treatment. These eye drops can help maintain one’s intraocular pressure (IOP) at a healthy level and are an important part of the treatment routine for many people.

When using multiple eye drops, there are two considerations. First, eye drops are absorbed only while in direct contact with the surface of the eye. The longer the drops stay in place until absorbed by the eye, the better the efficacy. This can be achieved by keeping your eyes closed for 2-3 minutes without blinking after instilling the eye drops. Second, when taking multiple drops, wait at least five minutes between drops. This time period will allow for maximum absorption of each drop and prevent it from being washed out by the next drop.

Since the eye can only hold one drop of liquid at a time until it is absorbed, it is only necessary to use one drop of the medicine at a time and using more than one drop at a time will result in the excess drop trickling down your face. Remember to close the bottle each time after instilling drops as an open bottle can become more easily contaminated. For contact lens wearers, remove contacts prior to instilling glaucoma eye drops. Your contacts may be reinserted after 15 minutes after the last eye drop.

Like all medications, glaucoma eye drops may have possible side effects that vary per individual and may include stinging or momentary irritation when instilling; red, irritated eyes afterwards; dryness; or an allergic reaction such as lid swelling, pain, or blurry vision. One way to help with a stinging/ burning sensation or dryness is to use artificial tears before you instill the glaucoma drops, then wait five minutes before instilling your glaucoma drops. At bedtime, overthe-counter tear gels or ointments may be used that can help soothe your eyes overnight. If you use a tear gel or ointment however, use your glaucoma drops first, wait five minutes, and then instill the gel or ointment as the last medication as they inhibit drop absorption due to their ‘thick’ composition.

Work closely with your eye doctor to understand the purpose and goals of your treatment plan including the purpose of the eye drops, proper dosage, possible side effects, and a target IOP. In most cases, medicines used to treat glaucoma must be continued daily for the rest of your life. Follow-up as recommended with your eye doctor to evaluate the effectiveness of your treatment plan and pursue other treatment options if necessary.