Nasolacrimal duct occlusion:
The tear duct (nasolacrimal duct) runs from the punctum, a pinpoint opening in the eyelid, into the nose. When drops are put in the eye, some pass through the cornea and get to the inside of the eye, where they are medically effective. Most of the drop, however, runs into the nose, and thence into the bloodstream, delivering the drug to the rest of the body, where they can cause side effects. Side effects are defined as effects of drugs on either the eye or other parts of the body which are not the intended effects for which the medication was prescribed. When pressure is applied with the index finger to the punctum and tear duct for 1 to 2 minutes following drop instillation, about 50% more medication gets into the eye. This gives more effective pressure lowering, a longer duration of action of the drops, more consistent lowering of intraocular pressure, and a reduction in the swings of pressure, in addition to fewer side effects elsewhere.
When multiple eyedrops are prescribed, these must be taken at a minimum of 10 to 15 minutes apart. Drops taken a minute apart will wash each other out of the eye and the full effect will not be obtained.
This is the most important point we can make about taking glaucoma medications. We have seen patients’ pressures drop from 30 to 15 with proper spacing and occlusion. Many other patients who had progressive visual loss and were facing surgery, stabilized with this simple technique. Some even reduced the amount of medications they were taking.