MEDICAL literature of all ages is full of recorded cases of ocular reflex neuroses. In former times they were recorded more as peculiar and not understood phenomena; as curiosities, rather than in a scientific sense admitting of explanation. Each year as conducted experiment and investigation is carried on, and as the nervous physical and psychical functions and their intricate relationship are gradually unravelled, and become better understood, the curious gives way to the matter of fact, and the former phenomena to natural and fairly well understood laws.
The subject is very extensive and far-reaching. We have neither time nor space to attempt exhaustive treatment. Ours a duty to schedule and classify; to record action and reaction; to collect authentic cases, of every possible variety, and from this maze and aggregation endeavor to deduce, in the future, some general and well established laws.
DEFINITION.-Nerve reflex is a direct transference of centripetal excitations to centrifugal paths, or vice versa, without the cooperation of the will.
All animal activity and functional force depend upon and is the result of physiological reflex action, whose general laws and pathways are understood.
The reflex is physiological as long as it is in harmony with normal functions and activities.
When the reflex excitations result either in over or under activity, it then becomes an abnormal reflex, or a neurosis.
Physiological reflex action, as well as reflex neurosis, may be manifested either as motor, sensor, or functional phenomena.
The contraction of the pupil to light is an example of physiological reflex; here impression is conveyed by the nerves of special sense (retina and optic nerve) to the brain centres, and then reflected back through a motor nerve (third nerve) producing contraction of the pupil. Or the sight of a disgusting object may produce nausea; here the pathway of the nervous reflex is through the same nerve of special sense to the pneumogastric, and hence the consequent nausea, a neurosis. Or the fluttering, increased rapidity of the heart beat; or the blanching of the checks, in the presence of great danger, will again represent the functional features of a reflex neurosis.
The fact that these nerve impulses, originating in one system of nerves, may be transmitted to another system and reflected back again, from sensor to motor or functional, presupposes a close connection and intimate correlation between the cerebro-spinal and the sympathetic systems of nerves. Such intimate relationship and blending are anatomical and physiological facts.
The great sympathetic system of nerves is a series of closely connected ganglia, extending along each side of the spinal column, from the head to the coccyx, communicating with itself from side to side, as well as with both roots of the spinal cord as they emerge. It communicates likewise with al the other nerves of the body, uniting with the fourth and sixth nerves, in the cavernous sinus; and with the olfactory and auditory at their ultimate expansion, as well as being in close connection with all the other cranial nerves, through its cranial ganglia; forming thus the great blending and binding pathway and influence.
While at the summit of the spinal cord is the medulla oblongata, a congregation of ganglionic centres, and series of sensory ganglia from which arise the seventh, eighth, ninth, tenth, eleventh and twelfth nerves; and also gives root to fibres of all the remaining six cranial nerves in its centre, the fourth ventricle. In addition to this, it is united by commissural hands in all parts of the brain proper, and contains most of the fibres, which are distributed to the other parts of the encephalon; and hence it transmits both the motor and sensory impulses, as they pass from and enter the cerebrum.
In the light of this intimate blending and interpenetration of the cerebro-spinal and sympathetic systems of nerves, their mutual influence, one upon the other, would seem to be, not phenomenal, but almost an anatomical and physiological necessity.
Since the normal processes and pathways of the reflection are so numerous and complex, it is easily intelligible how numerous and complicated the disturbances of motility, sensation and function may be, and from how many different points abnormal influence may be excited and reflected, in motor, sensor and functional, as well as in psychic, centres. The form and character of the neurosis may thus be extremely numerous, and hence the recognition of the primary cause may be not only difficult, but at times impossible to locate.
Starting out with the above statements clearly in mind, this discussion of ocular neuroses resolves itself into a simple statement of observed and recorded facts, without the necessity of delay for extended and elucidating argument.
Ocular reflex neuroses may be considered under two general headings:.
I.-Reflex-neuroses from the eyes to and implicating other parts and organs.
II.-Reflex-neuroses from other parts and organs, affecting the eyes.
These reflex activities may be variously manifested, for the same cause may result either in sensory, motor, functional or organic disturbances, and there is no known fixed law to determine which it will be; in fact, these groups often present no sharp lines of demarcation, but frequently overlap each other at many points, so that, in certain cases, we meet with symptoms characteristic of two or more groups.
Under the first heading, or reflexes from the eyes producing disturbances in other parts and organs, the most important and the most frequently met with, are resulting from optical anomalies, viz., myopia, hyperopia, astigmatism.
Various and distinctly different results may follow from the same apparent cause, such as pains in and about the eyes, headache, neuralgia, photophobia, nictitation, diplopia, nausea, vertigo, dizziness, restlessness, insomnia and mental aberrations.
Local inflammations may follow same cause, as conjunctivitis, blepharitis, styes, corneal inflammation or ulceration, retinal hyperaemia or optic-nerve congestion, etc. These are all the direct results of irritation produced by eye- strain, transmitted through the optic nerve to and though the cerebro-spinal and sympathetic systems of nerves, finding outlet either as a perverted sensation, a motor impulse, or causing functional disturbance, and, may be, organic changes in various parts.
Under this heading we must also place heterophoria and its disturbing consequences, for it is not the deviation in direction of the eyes themselves directly which causes such unpleasant results, which are almost identical with those caused by optical anomalies, but it is through the resulting lack of visual equilibrium, and the difficulty or impossibility of forming retinal images and impression on the necessary “identical points,” which is the prime cause of the long list of troubles which may follow in the wake of this lack of muscular equilibrium of the eyes.
If we ask why the same apparent condition may produce such widely different results, we should remember, as before remarked, that the laws of reflex action are not universal. The same irritation, functional or organic, may produce radically different reflexes in different subjective, or in the same subject at different times. While in other cases the same apparent optical or muscular error does not seem to be attended by the least irritating reflex results. There must be some nervous predisposition existing in the subject afflicted aside from the local points of irritation. This would seem to be proved by the fact that they in whom reflex troubles are most common are usually of a neurasthenic temperament.
To illustrate this variety of susceptibility coming, under my personal observation, a few brief cases, which are familiar and numerous, may be given:.
A scholarly minister, about 50, had, for years, suffered with neuralgic pains in and about the eyes, frequent nausea, nervous prostration, etc., the familiar picture. A + .25 Dc. ax. 90 degree, brought perfect relief and restored health.
In another case, a neurotic boy, age 15, had frequent epileptoid attacks, which a -.5 Dc. ax. horizontal removed, thus showing the small amount of error producing aggravated results in predisposed neurasthenic subjects.
A typical case, showing on utter lack of susceptibility, may now be examined. A gentleman, age 30, applied to me for aid in defective vision. he had never seen as well as other people. Had never been subject to headaches, neuralgia, nor other signs of reflex irritation; only “could not see well.”.
Examination showed V=15/30. With + 6 Ds. + 1.25 Dc. ax. 45 degree in the R. eye, and same combination, with ax. 135 degree in L. eye, gave him v=15/15. He continues to wear this glass with great physical comfort and personal satisfaction. Under ordinary circumstances we would have expected much nerve reflex irritation to be associated with such an optical condition.
Again, a young lady, 18 years old, wore a + 2 D. for six or eight years, with great relief to former suffering. As the end of this time she again began to have reflex irritation symptoms to a very annoying degree. The addition of a. 25 Dc., ax. 90 degree brought instant and permanent relief, thus showing that the neurasthenic predisposition may be different in the same individual at different times, influenced, no doubt, by other general conditions and nerve irritations, originating at parts other than the eyes.
