CHAPTER XIX HeEapACcHE, NEURALGIA, AND EYESTRAIN (Part 4)

and when a weakness of one corresponds to a hyperphoria it is confirmatory of the latter. When these tests show that the power of all of the muscles is subnormal it is well to consider whether we are not dealing with a general nervous or muscular weakness, which may be the origin of any anomaly of muscular balance present. After we have gathered all of the information we can from the different tests already enumerated, including the one for cyclophoria, we have all of the data we can obtain from the muscles themselves, HEADACHE, NEURALGIA, AND EYESTRAIN 457 and should exclude all of the other possible causes of eyestrain be- fore we speak positively of the diagnosis. The final test in a doubt- ful case is the result of treatment. Permanent relief establishes the fact that the eyestrain was due to the heterophoria which has been corrected, provided we can exclude the effects of suggestion, but a temporary one does not. We may obtain a temporary, or a partial relief from the correction of a refractive error, or of an imbalance of the muscles, or of both, when the symptoms depend partially, but not wholly on these errors, and in such cases we should seek else- where for the cause, rather than try many times to secure an elusive balance of the muscles. EYESTRAIN DUE TO CAUSES OUTSIDE OF THE EYE The intimate relations that exist between the eye and all other parts of the body cannot be insisted upon too strongly. The con- nection between the eye and a viscus situated in the abdomen is just as close through the nervous, circulatory, and lymphatic systems, as that between any other two separate organs, and we find that the eye reacts to troubles located in distant parts just as other organs react to troubles in the eye. Not infrequently we have nausea and vomiting occasioned by ocular disturbances, and sometimes we have all of the symptoms of asthenopia and eyestrain induced by gastric derangement. A very proper objection can be raised to calling these symptoms by the name of eyestrain when their origin is not situated in the eye, but as in all cases they are the product of a nervous irritability induced by a fault in some organ or other, so that they are in reality reflex, and as there is nothing about them by which we can determine in what organ the trouble is situated, it is convenient to consider them all under one name. We can then speak of nervous asthenopia or eyestrain when the causative condi- tion is situated in the nervous system, and of reflex asthenopia or eyestrain when the symptoms are excited by trouble outside of both the nervous system and the eye. The last could be divided, perhaps, into as many varieties as there are organs in the body, morbid con- ditions of the blood, or toxic causes competent to produce it, but this would give us an innumerable number of forms that differ only in the location of the fault. Nevertheless it is a common custom to speak of these symptoms when they are excited by abnormal condi- tions in the nose as nasal asthenopia or eyestrain, because a great 458 DIAGNOSIS FROM OCULAR SYMPTOMS deal of attention has been called to this variety of late, and it may be that as more regard comes to be paid to the other varieties we shall become accustomed to speak of uterine, gastric, and other forms, or that a better term will be devised for these reflex symp- toms, no matter what their origin. At present we shall include all of the cases which present symptoms of eyestrain that are depen- dent on causes to be found outside of the eye under two headings: nervous asthenopia, which may be made to include not only or- ganic lesions of the central nervous system, but also functional de- rangements that are due to toxic causes, or to impoverished condi- tions of the blood which do not seem to depend on organic lesions elsewhere, and nasal asthenopia, which may serve as a type of the eyestrain induced by organic troubles in other organs. Nervous Asthenopia First among this class of cases comes a very large group in which the patients are suffering from the results of over work, over worry, and lack of rest. When an energetic hard worker tells us that he has to drive himself to do the work which he has always been accus- tomed to enjoy, that he dreads it and has to spur himself on to per- form his daily duties, or, if he will not admit the loss of enjoyment, acknowledges that he feels the pressure of a sense of duty much more than he did, we have to consider whether he is not threatened with a nervous breakdown, and whether the symptoms of eyestrain which he presents are not produced by the general nervous irritation. In such cases the symptoms are of fairly recent date, and have been steadily progressive, so that, as a rule, we have little difficulty in recognizing nervous exhaustion to be the probable cause, except when the patient is aware of his own condition, is determined to conceal it, and refuses to admit anything that might indicate his need of the rest he proposes to avoid. In a case in which the history and the onset of symptoms indicate a nervous exhaustion of this nature it is not always wise to attempt to relieve the symptoms of eyestrain at once, even though we may find a refractive error, or a muscular imbalance, the correction of which ameliorates the symptoms, for it often happens that the relief given by the correction impels the patient to persist in his work until he is completely broken down. An example of this nature was furnished by a gentleman sent by a physician, who was trying HEADACHE, NEURALGIA, AND EYESTRAIN 459 to get him to let up in his work, to have his eyes examined in search for the cause of his sufferings. The correction of a slight refractive error so overjoyed the patient by a relief of his symptoms that, in spite of the urgent warnings on the part of both his physician and myself, instead of lessening he increased his work, and became totally prostrated a few months later. Such cases are not uncommon, and as it is human nature to neglect warnings unless they are backed up by tangible symptoms, we should eliminate nervous exhaustion if possible lest we do harm by a correction that seems to be indicated at the time, but is not the fundamental cause. The tests for hetero- phoria are particularly apt to be unreliable and misleading, because when one is very tired a slight incoordination may well be expected to appear in the muscles of the eyes, as it is known to do in other muscles of the body. After the nervous system has had a chance to recuperate from its exhaustion through a suitably long vacation from work, or through the removal of the causes for worry, we may find that the muscular faults have disappeared, and that the refrac- tive errors were not the source of the trouble. A case in point was that of a man 38 years old, who was over worked, presented symp- toms of eyestrain, and gave a history of a former attack of nervous prostration. He had a manifest hypermetropia of half a diopter, one degree of exophoria, and no hyperphoria, according to the phorometer, although the sursumvergence of his eyes differed by one degree. During a vacation of five months his symptoms gradu- ally improved, and when he returned at the end of that time they were gone, he was hungry for work, as he expressed it, the acuteness of his vision had greatly improved, he could no longer see at a dis- tance with his glasses, and his muscular balance was perfect. So far as his eyes were concerned he needed only the correction of his hyper- metropia for reading, and during the past ten years the only atten- tion they have needed has been due to the onset of presbyopia. All symptoms of eyestrain were done away with completely and per- manently by the vacation, followed by a persevering avoidance of over work. Symptoms of asthenopia, or of eyestrain, sometimes are met with in anemia, and in convalescents who are debilitated, when perhaps they are caused by the impoverished condition of the blood. In these cases the correction of refractive errors is not apt to give relief, while the heterophoria is likely to be variable and puzzling. The same symptoms occur in neurasthenia, and in hysteria, in which 460 DIAGNOSIS FROM OCULAR SYMPTOMS the heterophoria, some form of which commonly is present, seems to be symptomatic rather than causative, as a rule. Some writers have thought that these symptoms may be caused by a condition of anesthesia, or of hyperesthesia of the retina, but if any such cases have come my way they have not been diagnosed correctly. In the great majority of cases in which asthenopia or eyestrain occurs in connection with a grave disease of the central nervous system it develops independently from some other cause. In a minority the symptoms induced by ocular trouble may simulate those of nervous disease, as in cases of chorea and epilepsy that have been cured through the treatment of an existing heterophoria, but in rare instances they appear to have been caused by the disease itself. Hansell and Reber have reported a case in which asthenopia with hyperphoria seemed to have been the first symptom of the onset of tabes, with a reflex immobility of the pupil as the second. The hyperphoria passed away spontaneously within a year. We cannot make a diagnosis of this nature except after a prolonged observation of the case. Little is known of the toxic causes of asthenopia, but we know that hot, burning, hyperemic eyes, with more or less headache and nervousness, are apt to be seen after a night’s debauch. An acquaint- ance of mine cannot smoke a single cigar without suffering the next day from red, burning eyes that incapacitate him to a certain extent for work. Commonly we attribute the asthenopia in such cases to the hyperemia of the conjunctiva and of the margins of the lids, and the balance of the nervous symptoms to toxic effects, but there was no hyperemia of the conjunctiva in a patient whose smarting eyes I tried in vain to cure until he was induced to stop smoking five or six cigarettes a day. At the end of a week of abstinence with no other treatment his eyes were well; after smoking as usual for a week they were as bad as ever, and abstinence thereafter resulted in a perfect cure. It seemed to be demonstrated in this case that the cause of the asthenopia was the toxic effect of tobacco upon the nervous system, and it hardly seems reasonable to exclude the other cases from the same explanation because of the added symptom of a vasomotor dilatation of the blood vessels of the conjunctiva. HEADACHE, NEURALGIA, AND EYESTRAIN 461 Nasal Asthenopia Pressure in the nose is able to give rise to symptoms not only of asthenopia, but to all of those indicative of eyestrain, and these symptoms may seem to be so clearly dependent on some ocular fault that it is almost impossible at times to convince not only the patient, but even to realize ourselves, that the trouble is not in the eyes. When the symptoms of eyestrain are not relieved by a correction of the refractive errors my experience has led me to examine the nose as the place where the cause is next most likely to be found. Per- sonal impressions are absolutely untrustworthy for a variety of rea- sons, so it may be wrong to consider nasal troubles to be a more frequent cause of eyestrain than heterophoria, but there are no statistics dealing with the relative frequency of nasal asthenopia and of heterophoria from which such an impression can be corrected. The first writer of whom I am aware to call attention to the nose as the possible cause of asthenopia was Gruening in 1886, and per- haps the second was myself in 1894, but the subject did not attract much attention until during quite recent years. We know now that in many cases the pressure in the nose is at a point where it causes no obstruction to the breathing, and that in such cases the patient may have very good reasons for believing that he has never had any trouble in that organ, as the pain is referred to the eye and head, and seldom if ever is local. The most active nasal conditions in this class of cases are pressure contact and hyperesthesia of the mucous membrane, of which the following discussion is taken from Ziegler: ' “The first and most important causative agent is a condition which we may term pressure contact. The middle turbinate is usually the offending member, and is so often wedged in between the two vas- cular cushions of an engorged inferior turbinate and a sensitive septal puff that many mystifying reflex impulses are originated, the most pronounced of which are localized muscular twitchings, or choreiform movements of the face, head, and neck, while intense frontal headache and eyeache are more frequent effects. The middle turbinate, however, is not always the offending member. I have seen an inferior turbinate cause similar disturbances which were promptly relieved by the removal of the spur. The pull of con- tracting adhesions between the middle turbinate and the septum may also cause annoying reflexes. Another important etiological ele- 462 DIAGNOSIS FROM OCULAR SYMPTOMS ment is hyperesthesia of certain areas in the upper air chambers of the nose. These sensitive points are most frequently located in an area covering the tubercle of the septum, which when irritated, quickly becomes engorged with blood and thus makes pressure against the closely approximated middle turbinate. Irritation of this sensitive area is so provocative of distinctly localized eye symp- toms that I have long since dubbed it ‘the eyespot of the nose.’ ” Another element that needs to be taken into consideration is that of nasal obstruction, but this is much more likely to attract the attention of both the physician and the patient, while it may perhaps be of less importance as the cause of eyestrain because it is apt to act indirectly by increasing the sensitiveness of the whole system and so rendering it more liable to reflex disturbances. Inflammation in the accessory sinuses also may act indirectly in this manner, but it acts directly as well through the pressure exerted upon the walls of the cavities by the accumulated secretion. In a great many of the cases of nasal asthenopia the symptoms come on, or are aggravated, during reading, writing, or other near work, and a useful test is to have the patient take his accustomed position for reading and maintain it for a few minutes with his eyes closed. If the symptoms come on just the same as when he is actually reading or writing, the cause can hardly be in the eyes, but it probably is located in the nose, because the usual position for near work is apt to compress the blood vessels in the neck enough to in- duce an over supply of blood to the nose and so to increase any pressure contact that may be there. Another diagnostic test which is very useful is to press with a bit of wet cotton on an applicator against the point where the middle turbiate seems to touch the septum. If our eyes have deceived us and there is no contact, the probe will pass between these tissues and cause nothing but local irritation. If the contact is real the probe will be arrested, and if its pressure causes the headache to increase at once, together perhaps with pain and weeping of the eye, we have reason to feel confident that we have discovered the source of the eyestrain, while if nothing except local irritation is produced the cause probably is elsewhere. As Ziegler has pointed out, the middle turbinate frequently is so hidden by the swelling of the other tissues in the nose that we are obliged to shrink the inferior turbinate be- fore we can get a sight of the place which is the commonest seat of trouble. This shrinking of the tissues may be accomplished with HEADACHE, NEURALGIA, AND EYESTRAIN 463 either adrenaline or cocaine carefully applied with cotton on an ap- plicator, and forms of itself another valuable test. Occasionally it brings into view an unsuspected spur of the septum that impinges on one of the turbinates, and sometimes this can be demonstrated to be the cause of the symptoms by their instant cessation as soon as the apex of the spur is freed from the tissues into which it is pressing. Similarly the immediate amelioration of the symptoms as soon as a point of pressure, where there is no spur, is relieved gives us pretty definite information concerning the nature and location of the trouble. It is seldom possible to ascertain the presence or ab- sence of pressure by inspection alone. This shrinking of the tissues may reveal an inflammation of the frontal sinus, or of the anterior ethmoidal cells, as the cause of the symptoms, particularly when a gradual rather than a sudden alle- viation of them is accompanied by an increase of clear fluid in the nose. In such a case we make a diagnosis of catarrhal sinusitis and understand that the escape of the secretion has been obstructed. If pus appears in the nose the inflammation is purulent and the patient has an empyema of the sinus. It is also possible for the engorged and hypersensitive condition of the mucous