Baltimore Washington Eye Center, Maryland

Tuesday, October 18, 2011

Contact Lenses as Drug Delivery Devices?

Why use a contact lens to deliver drugs?  It would seem that if you can achieve the same objective using eye drops; this would be the preferred method.  However, eye drops have several drawbacks.  The amount of medication that actually comes in contact with the eye and is absorbed is small.  The greatest issue is not this, but compliance.  Drops may be difficult to administer, due to an unsteady the hand, arthritis or simply forgetting to use them. 

Many patients do not view drops as medication and do not feel they are important.  If we are using them to prevent a condition that has no symptoms, like glaucoma, they might not take the treatment as being necessary.  Plus they are inconvenient, especially if they require refrigeration or have a short shelf life.  To this effect a contact lens that contains a membrane that will release a measured amount of medication over time is being developed.  As the membrane degrades it could release any type of medication.  It could release an antibiotic, pain killer or anti-inflammatory.  Experiments have shown that it can release a measured amount of antibiotic for more than 100 days.  This technology could be coupled with a lens that measures the intraocular pressure and then delivers the pressure treating medication.  Currently the device only exists as a passive one.  The future of such technology is limitless.