Electronic apparatus for the application of electrical current to the eye for treating diseases thereof, for example macular degeneration & floaters
US Patent 5,522,864
Apparatus and method for ocular treatment
Macular degeneration and other ocular pathology in a subject is treated by the steps of: placing a positive electrode of a direct current source in electrical contact with a closed eyelid of a subject; placing a negative electrode of the source in electrical contact with the posterior neck of the subject; and causing a constant direct current of 200 .mu.A to flow between the electrodes through the subject for about 10 minutes. The source can be a portable, battery powered constant direct current generator which is affixed to the subject. The subject is thus enabled to ambulate during treatment.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the medical treatment of ocular disease. More particularly this invention relates to an electronic apparatus for the application of electrical current to the eye for treating diseases thereof, for example macular degeneration.
2. Description of the Prior Art
Macular degeneration is a debilitating ocular disease having hemorrhagic and exudative variants, both of which are susceptible to safe and efficient treatment by the invention hereof. Treatment typically results in amelioration of the ophthalmoscopic manifestations of the disorder, and substantial restoration of central visual acuity.
It is proposed in Fedorov et al., U.S. Pat. No. 5,147,284, to treat diseases of the optic nerve and retina by the application of a pulsed 3.5 magnetic flux, the magnetic field induction being from 0.1 T to 0.25 T. However the technique is invasive, requiring exposure of the posterior portion of the eyeball and optic nerve and introduction of the inducer into the orbit.
It is proposed to treat glaucoma with the application of transcutaneous electrical stimulation from Liss et al., U.S. Pat. No. 4,614,193. Liss et al. discloses the application of pulsed electrical current at a level less than 4 milliamperes, the pulse trains occurring at 12-20 kHz, amplitude modulated at 8-20 hz, and having a 3:1 duty cycle. Applying this waveform through electrodes positioned on the temple and on the ipsilateral hand, Liss et al. achieved an approximately 28% reduction in intraocular pressure in the treated eye. To the knowledge of the inventors, passage of electrical current through the eye (hereinafter "transocular electrical conduction") has not been used in the art for the treatment of macular degeneration.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide an improved apparatus and method for the treatment of macular degeneration and certain other ocular pathology.
It is another object of the present invention to provide a safe, improved, noninvasive method for the restoration of vision by treating the eye with transocular conduction of electrical current.
These and other objects of the present invention are attained by a direct current generator that produces low level direct current, electrodes being placed on the closed eyelid and on or near the occiput of the skull. The inventors have found that this waveform is particularly effective in the treatment of macular degeneration, and is believed to benefit a variety of other ocular disorders. While the principles under which the invention produces its beneficial effects are not fully understood, and without restriction to a particular theory of operation, it is suggested that transocular electrical conduction as practiced in accordance with the invention may restore cellular electrical balance by changing potentials across cell membranes. This may alter the levels of certain ions and molecules toward a desirable equilibrium. Other physiological effects are believed to be produced: reduction of alkalinity proximate the passage of electrical current and the production of low levels of hydrochloric acid; attraction of oxygen to the region; localized vasoconstriction; reduction of local hemorrhage; sedation; increased tonicity of local tissues; antisepsis; production of desirable fibroplasia; and reduced neuromuscular irritability.
In accordance with one aspect of the invention macular degeneration in a subject is treated by the steps of: placing a first electrode of a direct current source in electrical contact with a closed eyelid of a subject; placing a second electrode of the source in electrical contact with a site remote from the eyelid of the subject; and causing a direct current of 1-1000 .mu.A to flow between the electrodes through the subject for about 10 minutes.
In accordance with another aspect of the invention the source is a portable, battery powered constant direct current generator which is affixed to the subject. The subject is thus enabled to ambulate while the direct current is flowing therethrough.
In accordance with yet another aspect of the invention, the first electrode is a positive electrode, and the second electrode is a negative electrode. The remote site for the second electrode is the posterior neck of the subject.
In accordance with still another aspect of the invention, the current flowing between the electrodes is 200 .mu.A, and is constant in magnitude.
Patient MH, born Feb. 18, 1916, complained of reduced central visual acuity, and had a medical diagnosis of macular degeneration. She was receiving medication for hypertension and for elevated cholesterol. Prior to treatment the eyes were free of all other pathology. Pupillary responses were normal, and the best corrected visual acuity using the Snellen chart was O.D. 20/200 , O.S. 20/200. Near visual acuity was best corrected to 2M print. Low vision aids were prescribed to assist her adaptation to her visual loss. She returned after 13 months with little change noted on her part. Visual acuity was again measured at the same level, 20/200 in each eye. A contrast sensitivity test was done at the same time, and revealed that visual acuity was in the 20/200 range in both eyes. A visual field examination was normal for both form and blind spot.
One month later she began a series of transocular electrical conduction treatments. Using a constant direct current generator, 200 .mu.A was applied for 10 minutes, with the positive pole attached to the closed eyelid, and the negative pole attached to the back of the neck. After thirteen sessions, averaging three times a week, acuity was remeasured with results as shown in table 1-1.
TABLE 1-1 ______________________________________ after 13 sessions Right Eye Left Eye Both eyes ______________________________________ Snellen Chart 20/100 plus 2 20/100 20/80 plus 2 Contrast sensitivity 20/70 20/70 ______________________________________
At near, the patient could read 1M print easily. The results after 20 sessions are given in table 1-2.
TABLE 1-2 ______________________________________ after 20 sessions Right Eye Left Eye Both eyes ______________________________________ Snellen Chart 20/80 minus 1 20/80 minus 1 20/70 Contrast sensitivity 20/70 20/80 ______________________________________
Treatment was discontinued. A progress evaluation was done two months later with the result as shown in table 1-3
TABLE 1-3 ______________________________________ Right Eye Left Eye Both eyes ______________________________________ Snellen Chart 20/80 20/80 minus 1 20/60 ______________________________________
Near vision acuity was now 0.8M. The same findings were again duplicated using contrast sensitivity testing.
Patient JC was born Dec. 15, 1917, and when first seen for evaluation complained of inability to read and see clearly both at far and at near. A diagnosis of macular degeneration was confirmed by two ophthalmologists. He was currently taking medication for hypertension and diabetes. His best corrected visual acuity was OD 20/50; OS 20/30. The eyes were free of all other pathology.
He was treated in the manner described in Example 1. After six treatments, he was re-evaluated with the results shown in table 2-1.
TABLE 2-1 ______________________________________ Right Eye Left Eye ______________________________________ Snellen Chart 20/40 20/25 ______________________________________
Blood pressure before and after treatment was 190/80 and 120/70 respectively. Contrast sensitivity done prior to treatment was as follows:
TABLE 2-2 ______________________________________ OD OS ______________________________________ Aug. 31 20/70 20/50 Sept 18 20/40 20/30 ______________________________________
A visual field examination on September 18 revealed a marked constriction of the color field at near, measured with a one millimeter target at 14 inches. There was also a three time enlargement of the blind spot on the right eye and about a four fold enlargement of the blind spot in the left eye. The color fields were also markedly constricted in the left eye.
Treatment was continued for another eight sessions. He was seen for a progress evaluation on October 5, with the results as shown in Table 2-3.
TABLE 2-3 ______________________________________ Right Eye Left Eye ______________________________________ Snellen Chart 20/30 20/25 plus 2 Contrast sensitivity 20/30 20/25 ______________________________________
A visual field was repeated, and there was a marked improvement or expansion in the color fields for both eyes. The blind spot had also reduced and become much more normalized in the right eye, and although enlarged in the left eye, was reduced by 100% over the findings since September 18.
Treatment continued, and he was seen again on October 26 for a progress evaluation, with the results as shown in table 2-4:
TABLE 2-4 ______________________________________ Right Eye Left Eye ______________________________________ Snellen Chart 20/30 plus 2 20/25 plus 2 Contrast sensitivity 20/25 20/25 ______________________________________
The color field had continued to expand on visual field measurement. The blind spot was still enlarged in both eyes.
Treatment continued, and he was seen after approximately 30 treatments on November 20, with the results as seen in table 2-5.
TABLE 2-5 ______________________________________ Right Eye Left Eye ______________________________________ Snellen Chart 20/30 plus 3 20/25 plus 2 Contrast sensitivity 20/30 20/25 ______________________________________
The visual field was repeated, and the color field had not expanded to what would be considered normal levels. The blind spot was only enlarged by about 10% now in each eye.
Treatments continued through December 16, with all findings remaining the same. In a progress evaluation on February 12 of the following year, the results were as shown in table 2-6.
TABLE 2-6 ______________________________________ Right Eye Left Eye ______________________________________ Snellen Chart 20/30 plus 1 20/25 plus 2 Contrast sensitivity 20/25 20/25 ______________________________________
Subjectively, he reported much better vision both at far and near, could read easily, drive safely, and reported that he was seeing things much brighter and clearer at all distances, and at all times.
Patient HD was born on Apr. 2, 1919, and was first seen on June 6 with a history of macular degeneration, and central scotoma with metamorphosis. No other ocular pathology was noted, and the she was on no medication.
Measurement of her central visual field revealed a large central scotoma in each eye corresponding to the macular area. Her visual acuity is shown in table 3-1
TABLE 3-1 ______________________________________ Right Eye Left Eye ______________________________________ Snellen Chart 20/100 20/70 Contrast sensitivity 20/100 20/80 ______________________________________
Re-examination after her summer absence in the Fall revealed the results shown in table 3-2.
TABLE 3-2 ______________________________________ Right Eye Left Eye ______________________________________ Contrast sensitivity 20/100-20/200 20/70 ______________________________________
She began a series of transocular electrical conduction treatments under the conditions of Example 1, except that the treatments were performed weekly for six weeks.
Re-examination on November 11 revealed the results shown in table 3-3.
TABLE 3-3 ______________________________________ Right Eye Left Eye Both eyes ______________________________________ Snellen Chart 20/50 plus 2 20/40 plus 2 20/30 Contrast sensitivity 20/100 20/50 ______________________________________
She reported that an ophthalmologist who saw her the previous week said that her visual acuity was now stable, and that ocular hemorrhage had diminished. She reported seeing much better at all distances and was able to read comfortably and efficiently.
Patient CR was born Feb. 13, 1917, and was first seen on December 9. A cataract had been removed from the right eye, and she at that time had a cataract in the left eye. She had a diagnosis of senile macular degeneration in both eyes. She was taking medication for hypertension, iron for anemia, and occasionally a sleeping pill.
Her best corrected acuity was OD 4/200th's vision, OS 10/70th's vision, near acuity was 1.2M. Due to her poor vision, contrast sensitivity testing was not possible. By placing a 2.5 power telescope in front of the left eye, visual acuity could be improved to 20/40 minus 1.
Transocular electrical conduction treatment was begun under the conditions of Example 1. After seven treatments her visual acuity was OD 400; OS 20/80 plus 1. Her near visual acuity was now 1M with reading glasses. A 2.5 power telescope in front of the left eye produced a visual acuity of 20/40 plus 2. She reported much improved subjective visual acuity both at far and near, and noticed that vitreous floaters had improved.
After six more treatments she was re-evaluated on February 17 of the next year. Visual acuity was OD 20/400; OS 20/70. Visual acuity through a 2.5 power telescope was almost 20/30.
In summary her acuity in each eye improved approximately 100% over a course of 13 sessions.
Patient HD from Example 3 was subsequently treated weekly over a period of 12 weeks with pulsed electrical current using the Liss Cranial Stimulator noted herein. The stimulator was operated at 400 microamperes for 10 minutes. The wave form consisted of "on:" periods of pulse trains alternating with "off periods" at 500 hz and a duty cycle of 3:1. The pulse trains occurred at a frequency of 15 khz and were amplitude modulated at 15 hz. Results were as follows:
TABLE 6-1 ______________________________________ Right Eye Left Eye ______________________________________ Before Treatment 20/50-1 20/50-2 After Treatment 20/40-1 20/40-2 ______________________________________
Patient CT complained of bilateral vitreous floaters, and underwent transocular electrical conduction treatment was performed according to the conditions of Example 1, except that treatments were undertaken thrice weekly for a period of two weeks. After completion of the treatments the patient reported that the floaters were no longer perceptible.
While this invention has been explained with reference to the structure disclosed herein, it is not confined to the details set forth and this application is intended to cover any modifications and changes as may come within the scope of the following claims:
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Aetheric Polymeric Matrix Material: Orgonite
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