CHAPTER I Symptoms, History TAKING, AND DIFFERENTIATION (Part 2)

is greatly neglected. To many minds it seems to mean that we should sit down with pencil and paper, question the patient, begin- ning with his ancestry, write notes on all manner of unrelated subjects, and work down gradually to his present condition. Such a method is not only difficult and wasteful of time, but is asinine. It antagonizes the patient, who cannot see the bearing of such an interrogation, and therefore replies carelessly, if not impatiently, and this, instead of aiding us, makes our task more difficult. Na- ture has granted to some more than to others the power to draw out essential points from people of the most diverse characters and dispositions, but we need to cultivate such power as we have until it takes only a few moments to learn the facts needed for our guidance. A certain routine should be followed, but not the one 12 DIAGNOSIS FROM OCULAR SYMPTOMS indicated above. The following may serve as an example, though it is no better than any other that is equally thorough. While the patient is telling what he wishes to say we listen atten- tively, jot down some notes, perhaps, but rely mainly on memory for the present, and at the same time glance over the entire face, with especial attention to the regions of the preauricular gland, the lacrimal sac, the lids, and their margins. Without interrupting the narrative we press gently upon the lacrimal sac and observe if there is any regurgitation from the punctum, draw down the lower lid so as to reveal its palpebral conjunctiva, inspect it, and then in turn the bulbar conjunctiva, the caruncle, the semilunar fold, the cornea, the iris, and the anterior capsule of the lens, and take the tension of the eyes with the fingers, for this much of the examina- tion is to be made in almost every case. By this time we have the principal subjective symptoms in mind and may be guided by them, or by objective symptoms we have discovered, to devote attention to some particular tissue first of all, perhaps to study it by oblique ilumination. If no external lesion has become apparent we may evert the upper lid at this time, or defer the eversion until after the functional tests, which are pretty sure to interrupt the narrative, if it has not been completed. We first test the pupillary reactions, determine the vision of each eye separately, measure the corneal astigmatism with the ophthalmometer, ascertain the manifest re- fraction and the range of accommodation, investigate the balance of the extrinsic muscles, and then invite the patient into the dark room for an ophthalmoscopic examination. We should record all of our findings by these tests immediately. It now becomes neces- sary in many cases to dilate the pupils with a mydriatic, or to paralyze the ciliary muscle with a cycloplegic, and we have to wait until the drug has produced its effect before we can proceed. This is a good time to inquire into the history. Sometimes it is well to begin by rehearsing briefly our conceptions of the subjective symptoms and asking corrections; at other times this is unnecessary. If we start by trying-to ascertain as nearly as possible the date of the onset of the affliction and the nature of the early symptoms, the patient is apt to follow our lead readily when we inquire into his past troubles, his occupation and habits, and finally into his family history, for he is led to believe that the questions have been called forth by what we have found, and to take an intelligent in- terest in answering them. Very little time is taken in doing this, SYMPTOMS AND DIFFERENTIATION 13 unless the answers lead us to further investigation along some par- ticular line, while the patient, so far from being irritated, is likely to be impressed favorably by our interest in his case. Inquiry into the family history is out of place when the trouble is a purely local one with which heredity is known to have nothing to do, but when we find a condition in which the etiology is ob- scure, or one in the production of which heredity may have played a part, we should encourage the patient to rack his brains to furnish us as much information as possible about other members of his family, near relatives, and ancestry. When the same defect is present in several children of the same family, though not in the parents or near relatives, we need to inquire whether a grandparent, a great-grandparent, or any member of their families is known to have suffered in a similar way. A defect that reappears in widely separated generations, skipping the intermediate ones, is called atavistic. It is exceptional for us to be able to get a family history that covers more than three generations, and often we cannot get even this, so the results of this inquiry are apt to be incomplete and unsatisfactory. When a defect in several members of a family cannot be traced back, and is not known through other researches to be atavistic, we call it familial. Other hereditary defects are transmitted from one generation to the next, perhaps directly from parent to child, but often indirectly from an uncle or an aunt to the younger victim. Occasionally they seem to be transmitted through unaffected females to the males of the family. Some hereditary troubles are not apparent at birth, but develop in the younger person at about the same age that they did in the older one, and in such cases the family history throws light not only on the diagnosis, but also on the prognosis. In a comparatively small, though numerically large, number of cases we still need a report from the pathologist on a bit of tissue that has been excised for examination, on a culture taken from some discharge, or on the blood and excretions of the body, before we shall have amassed all of the symptoms obtainable. DIFFERENTIATION Even though each symptom alone is of little value, we shall find that when a number are taken together, some one, or some small group stands out prominently as indicating the tissue that is. the 14 DIAGNOSIS FROM OCULAR SYMPTOMS site of the lesion, or a definite fault of function. The other symp- toms enable us to place the trouble in a general group which includes many that are quite diverse, and then the presence or absence of certain characteristic symptoms empowers us to exclude one trouble after another until perhaps only a single one is left. Then we have made a diagnosis by exclusion. The differentiating charac- teristics may be subjective, objective, or contained in the patholo- gist’s report. The differentiation of eyestrain due to a refractive error depends on the relief of the subjective symptoms by the correction, that of an iritis from a glaucoma on the objective signs, that of a diplococcal from a pneumococcal ulcer of the cornea in an elderly person on the bacteriological findings. A correct diag- nosis is imperative in each of these four pathological conditions, for each disease will ruin the eye if it is neglected, and the right treatment for each will aggravate and make worse the one from which it needs to be differentiated. Every lesion in the human body may be supposed to interfere with certain tissues and func- tions in a definite way, and probably we could make the diagnosis rightly in every case if we could be sure that we appreciated every symptom presented at its true value, but as we cannot do this we make mistakes. When two persons suffer from the same trouble the symptoms will not be duplicated exactly unless the lesion is exactly the same in position, extent, and every other characteristic in both, so the clinical pictures must vary more or less. ‘The characteristic symptoms are not as pronounced in some cases as in others, and sometimes those presented are actually mis- leading, as in the early stage of some cases of iritis, when the redness of the eyeball may be fairly uniform, the pupil slightly dilated, and the conjunctiva have a little secretion, circumstances under which many an expert has been deceived. Finally, the symp- toms indicative of diseases of the eye are so interwoven in some cases with those produced by the diseases of the general organism that they can scarcely be disentangled, and many lesions of the eye are symptomatic of diseases of other organs of the body, so occasionally we have to make an excursion into the domain of general medicine, and call in the aid of other practitioners, in order to make a correct diagnosis.