Out With the Old, in With the New: The Best of AAO 2013

American Academy of Ophthalmology 2013

Roger F. Steinert, MD; Eric D. Donnenfeld, MD; Richard A. Lewis, MD


November 25, 2013

In This Article

Almost There: Drug Delivery Systems

Dr. Steinert: Now that we are on the subject of drugs, has anything new come along in the world of glaucoma?

Dr. Lewis: The biggest problem in glaucoma has been the chronic nature of the disease and the fact that less than half of our patients are taking the drug as we ask them to or don't take it at all. So there has always been a big effort towards enhancing drug delivery.

There are some very exciting developments in the drug delivery side of this problem for glaucoma patients. Punctal plugs have been in drug development now for a couple of years. They are going into clinical trial. It is adding a prostaglandin to a punctal plug; it delivers drug for about 3-4 months. It looks very exciting. It's one way to avoid having the patient taking the drops; they will be coming back to the ophthalmologist every 3 months. The ophthalmologist would be placing the plug, and then the plug would deliver the drug.

Interesting efforts are also being pursued in applying an applicator either in the fornix of the cul-de-sac of the conjunctiva or under the conjunctiva, as well as in the eye. So, a whole spectrum of drug delivery systems are in development that are very exciting for glaucoma and for other diseases as well. This will have a role in chronic uveitis and for patients who have postoperative inflammation. Glaucoma is going to be leading the way, and it could, in fact, change the whole paradigm of eye drop application.

Dr. Donnenfeld: This is a very significant unmet need. I am particularly interested in the punctal plug drug delivery. Obviously, they are starting with a prostaglandin analog, but this could be used for allergy drugs. It could be used for nonsteroidals and steroids. Cyclosporine can be given the same way.

The compliance issue that you speak of is a very important one. But in addition to that, some patients just can't take drops -- patients with emotional issues, patients who have arthritis, patients who are hemiplegic and can't move their arms. These patients need to be treated, and we have a solution now that may help these patients in a significant way. So I am very excited about this new delivery system. It's going to be a paradigm shift for many patients. Not for all patients, but for many patients.

Dr. Lewis: If you think about it, we have been using eye drops for more than 100 years, and we still haven't overcome all the problems of drug application. When we watch our patients applying the drug, it's embarrassing because we seldom teach them how to put the drops in. They don't know how to do it. They don't do it right. It would be wonderful if we could get past the eye drop and be able to know for a fact that the patient is getting the medication.

Dr. Steinert: When they use them, we are not even sure they are using the correct drops. You try to get them to bring the bottles in so you can verify that they are actually using what you think they are using.

Dr. Lewis: This is a good thing because it shifts responsibility back to the physician, who will be applying the punctal plug or applying the drug delivery system to the eye. They will have full understanding that the drug is finally being delivered with the right concentration.

Dr. Donnenfeld: The concentration is important. Because it's a continuous delivery system, we are using lower concentration. Toxicity should be lower. With around-the-clock coverage, you are going to have continuous drug delivery, so you are not going to have peaks and troughs. You are going to have a steady-state drug delivery. You will have better control of almost all disease processes for that reason alone.


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