Release: May 12, 2000
Contact: Kenneth Satterfield, 407-238-4161 (as of 5/12/2000)
A New Device Allows Patients to Deliver Medication to the Inner Ear for Treatment of Meniere's Disease, Vertigo, and Sudden Deafness
MicroWick(tm) represents a breakthrough for direct treatment of ear disease, application of higher concentrations of medicine, and prevention of systemic side-effects
Orlando, FL -- Otolaryngologist--head and neck surgeons have long believed that a safer, simpler, and more cost-effective procedure for treatment of inner ear disease is needed. One method that long eluded the ear surgeons was to emulate the current self-treatment for eye disease using medicated eye drops. However, getting medicine to the inner ear through a dropper proved impossible due to the location of the inner ear, which is inaccessible behind the tympanic membrane.
Dr. Herbert Silverstein, president of the Ear Research Foundation and Florida Ear and Sinus Center, Sarasota, FL, developed the MicroWick?, a 1 x 9 mm polyvinyl acetate wick that is placed through a tiny tube in the ear drum and then rests on the round window membrane, the door to the inner ear. The patient places into the ear canal the medication which is absorbed by the MicroWick? and transported to the round window membrane to the inner ear fluids. The advantages of placing medications directly into the inner include: (1) The diseased ear is treated directly without affecting the entire body; (2) A higher concentration of medication can be obtained. (3) Systemic side-effects of the drug are prevented.
Since August, 1998, 117 patients have been treated by the research team using the polyvinyl acetate MicroWick?. The disorders (Ménière's disease, sudden deafness, and autoimmune inner ear disease) all required direct treatment to the inner ear. An assessment of how the patients fared using the MicroWick? has recently been completed. The authors of the research study, "Self-Treatment of Inner Ear Using a MicroWick?" are Herbert Silverstein, MD, President of the Ear Research Foundation and Florida Ear and Sinus Center, William Lewis, MD, Jack Thompson, PhD, and Seth I. Rosenberg, MD, all from the Ear Research Foundation and Florida Ear and Sinus Center, Sarasota, FL. Their findings were presented before the American Neurotology Society meeting May 13-15 in Orlando, FL.
Methodology: The minor procedure is performed in a non-certified office minor surgery room. The ear is anesthetized; a laser tympanostomy or vertical myringotomy is made over the round window niche. The middle ear is examined with an endoscope or the operating microscope to determine if there are any obstructing membranes over the round window niche. A small pick is used to clear the round window; a vent tube is inserted into the tympanostomy over the window. The niche must be seen before inserting the MicroWick?. Medication is then injected onto the MicroWick? and will move through the tympanic membrane into the inner ear by diffusion.
Patients are then taught how to continue to place medication in the ear three times a day while lying for 15 minutes with the treated ear facing upwards.
After four weeks the MicroWick? and tube are removed in one unit without anesthesia. The tympanostomy is patched with a 3 mm square piece of Gelfilm containing an antibiotic ointment. The tympanic membrane usually heals rapidly in one to two weeks.
The study analyzed the progress of 87 patients with Ménière's disease; 20 had a diagnosis of sudden deafness and three had autoimmune inner ear disease. All used a MicroWick? in applying their prescribed medication. Results: Key findings of the study are:
For the 87 patients with Ménière's disease treated with dilute gentamicin 10 mg/ml ear drops for one to four weeks:
? abVertigo symptoms were relieved in 74 (85 percent) of the patients (during the 18 months that the MicroWick? had been used). Seven patients (eight percent) required further treatment. Two patients had a labyrinthectomy, three had repeated gentamicin/MicroWick? treatment, two had a combined retrocigmoid/retrolabyrinthine vestibular neurectomy.
-- abPressure in the ear was improved or relieved in 67 percent, and tinnitus was relieved or improved in 57 percent of the patients.
-- abHearing results were evaluated after dividing the patients into one group with hearing better or equal to 50db PTA (Pure Tone Average) and those with hearing worse than 51db PTA. In the better hearing group, complete hearing loss occurred in two patients, became worse in nine, remained the same in 20, and improved in four patients.
-- abFor those with worse hearing loss, complete hearing loss occurred in five of 37, remained the same in 21 of 37, improved in three of 37, and declined in 17 of 37. For 20 patients with sudden deafness and three with autoimmune inner ear disease, five had improved hearing. Patients treated earlier had better results; although one patient had improvement after one year following hearing loss.
-- abThe researchers found that when using steroids to treat inner disease, it is important to also use antibiotic eardrops once a day to prevent middle ear infection. Additionally, allowing the MicroWick? to remain in place for longer than four weeks may result in attachment of the device to the mucosa of the middle ear. Two patients had persistent perforations that were repaired with a fat graft.
Conclusions: The authors suggest that this self-treatment method using otic medication is a major breakthrough in the treatment of inner ear disease. It allows the otologist to treat inner ear disease using ear drops much like the ophthalmologist treats eye disease.
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