Eyeworld

EW GLAUCOMA 64 January 2017 by Maxine Lipner EyeWorld Senior Contributing Writer the lens. With the high dose lens, pressure reduction was even great- er. "The high dose lens had almost double pressure reduction," Dr. Ciolino said. "If that was the case in humans, it would present a more effective therapy than the standard of care currently." Dr. Kohane views this as excit- ing. "It has to be confirmed because it does go against what the current conventional wisdom about treating patients with latanoprost is," Dr. Kohane said. "If it's real, then we hypothesize that it is likely to be due to one or both of two things: the pattern of release, which is continuously supratherapeutic, or the absolute magnitude of delivery, which is greater than what is seen with drops." From a clinical perspective, Dr. Ciolino is hopeful that the drug-eluting contact lens is a step forward for patients. "My hope is that we have pressure reduction greater than what we get with drops and that this could be a therapy that addresses both compliance and improved efficacy," he said. Going forward, Dr. Kohane is optimistic that clinical studies will begin within the next year. "We're gearing up for it and planning but there are many variables, so we're not sure," he said, adding that the contact lens is a platform technol- ogy that can dispense antibiotics, antifungals, and steroids, as well as latanoprost. As a result, it's not clear whether the first human trial will be with latanoprost or another of these medications, which can be targeted to the front or back of the eye. EW Reference 1. Ciolino JB, et al. Latanoprost-eluting contact lenses in glaucomatous monkeys. Ophthalmology. 2016;123:2085–92. Editors' note: Drs. Ciolino and Kohane have no financial interests related to their comments. Contact information Ciolino: joseph_ciolino@meei.harvard.edu Kohane: Daniel.kohane@childrens.harvard.edu be seeing through the middle of the lens, and that allows us to maintain consistent drug loading and release irrespective of the size and shape of the contact lens," he said, adding that this peripheral drug polymer film is independent of other lens features that may change based on the particular patient's needs. Daniel Kohane, MD, PhD, pro- fessor of anesthesiology, and direc- tor, Laboratory for Biomaterials and Drug Delivery, Boston Children's Hospital, pointed out that the drug can be released more slowly since the film has a large ratio of surface area to volume. "As a result of the design, this lens is able to deliver large quantities of drugs at a rela- tively constant rate over very long periods," Dr. Kohane said. "That is something that previous designs could not do." With this lens, investigators were able to release therapeutic levels of latanoprost for 1 month, Dr. Ciolino reported. "It may have worked for 1 month, but we only studied it for 1 week," he said. Investigators considered the effect of latanoprost-eluting contact lenses on the eyes of glaucomatous monkeys in the study. Investigators compared commercially available latanoprost drops to the baseline, as well as considering drug-eluting con- tact lenses with high and low doses of the medication. "The low dose had an equivalent IOP reduction to the drops," he said, adding that at a few points it was a bit better with to 5% of the medication in a drop is absorbed by the eye," he said. "Of the medication absorbed, about 90% gets there by the cornea. So in many ways it makes sense to apply the drug exactly where it needs to go, in order to get it into the eye." A contact lens accomplishes this by placing the drug right on top of the cornea, he explained. Unfortunately, previous at- tempts to use drug-dispensing contact lenses have fallen short. One prior design used what was known as "uptake and release." "You take an off-the-shelf contact lens, allow it to absorb a medication from a solu- tion, and place that in the eye," Dr. Ciolino said, adding that one of the problems with that, depending on the indication, is the drug may come out too quickly from the lens to be clinically effective. Another problem with such lens designs is that it's difficult to load a lot of drugs into them. Unique features The new drug-dispensing lens studied here uses a polymer film to encapsulate and later dispense the drug. "We have a drug/polymer film that is heavily loaded with drug, but it's confined to a ring around the periphery of the contact lens," Dr. Ciolino said. This drug polymer film enables the drug to be loaded and later dispensed so that it doesn't obstruct the patient's view or inter- fere with breathability, hydration, or refractive correction. "Patients will Drug-dispensing contact lens offers new glaucoma approach I magine offering your glaucoma patients a unique contact lens instead of a prescription for drops. Such is the promise of a drug-eluting contact lens, and study results indicate it can deliver latanoprost at least as effectively as drops, according to Joseph Ciolino, MD, assistant professor of ophthal- mology, Harvard Medical School, Boston. Results from a study pub- lished in Ophthalmology indicate that pressure lowering with the lens using a low dose of latanoprost was equivalent to drop form, and a high dose contact lens was almost twice as effective, he reported. 1 Considering advantages The idea of using a contact lens to dispense the drug has several poten- tial advantages. In particular, it can help circumvent compliance issues. "Often patients forget to take their drops, especially when they need to be administered chronically," Dr. Ciolino said, adding that having a sustained drug delivery system is advantageous because when the contact lens is in place, the patient is getting the needed medication. Another advantage may be increased efficacy. In general, drops are not very efficient in terms of delivering medication to the eye, Dr. Ciolino pointed out. "Only about 1 Making contact Research highlight An OCT image of the contact lens. It allows the viewer to see that the drug polymer film has an open aperture for the patient to see through. Source: Joseph Ciolino, MD

• Cover