HYSTERICAL SQUINT.
In the hysterical form we see rather a rare variety of convergent squint, which is conditional on contraction of the interni through restriction of movement of the externi. Hysterical symptoms may at the same time appear in the eyes or elsewhere, still this does not always happen. As these cases are rare I will relate a few of those I have observed. (These cases are not included in the above statistics.)
Case 10. Anna R—, æt. 20, came under treatment in February, 1878, stating that on the previous day she perceived blindness of the right eye on waking; in the afternoon she felt particularly weary, and after she had slept about an hour woke with blindness in both eyes. No perception of light, good pupillary reaction, ophthalmoscopic report normal. Patient was treated with copious enemata and dismissed on the fifth day cured.
In February, 1880, she again came under treatment with blindness of both eyes, also perceived the previous day on waking. Convergent strabismus was present at the same time, of such a degree that the eyes converged to a point 10 to 20 cm. distant. The outward movement was suspended in both eyes. The attempt to turn the eye outwards is accompanied by short convulsive movements, and followed by an immediate rebound to the convergent position. She asserts her inability to see the movements of a hand before her eyes, is able, however, to move about in a strange room, unsteadily certainly, but with avoidance of obstacles; she sits down on a chair indicated to her, &c. The position of the eyes proves that there was no simulation in all this; it would be impossible for any person to simulate a strong convergent squint continuously for four to five days. Eight days after her admission the patient was dismissed with normal movement of the eyes and good vision.
Case 11. Miss Antonie E—, æt. 15, who has been treated by her family physician for various hysterical disturbances, suffered since the middle of December, 1879, from convergent strabismus with permanent but very varying deviation, which is at times very slight, and sometimes amounted to more than 7 mm. The movement outwards is in both eyes rendered difficult, still the outer edge of the cornea is brought to the outer angle of the lids with trouble and twitching movements. Homonymous double images are present, their mutual distance is alike in the whole field of vision, but is (six or eight weeks after the commencement of the squint) signified as being slight; at the same time a difference in height is present, the image of the left eye stands lower, prism 30°, base outwards, places the images just above one another. Nystagmus occasionally occurs in monocular fixation (with exclusion of the other eye). In due course a gradual improvement set in, the deviation and the distance apart of the double images became slighter, the outward movement better, and in the middle of April, 1880, four months after the trouble began, no squint and no diplopia were present, the outward movement normal, facultative divergence = 0.
The hysterical character of the visual disturbance showed itself when the vision was tested. I will first observe that repeated investigations with atropine showed emmetropia, while in the first investigation on the left side, No. 36 at 5 m. was not recognised with the naked eye, but only with weak concave glasses (with - ·5 D. V. = 5/18). With the right eye No. 0·8 was read fluently, from 0·75 she asserted she was unable to recognise a word, with - 2 D. V. = 5/36. It would be wrong to conclude from this myopia or spasm of the accommodation, for here, as in most cases of hysterical weak sight, it could be shown that whatever glass one chose to hold before the patient's eyes, was followed by an improvement in the statements. The same improvement in visual acuteness was repeatedly obtained in this case by a weak prism (3°), held before the fixing eye during monocular examination, and in the end, V. 5/12 was obtained for the right eye, as against 5/6 with a prism of 3°.
Finally, on May 1st, full visual acuteness was present on both sides. Field of vision and sense of colour normal.
Case 12. Mrs. B—, æt. 30, previously treated for various hysterical disturbances, has complained for about eight days of disordered vision, the binocular nature of which was proved as patient had herself observed that on closing one eye she could at once see clearly. Near objects to 15 cm. are seen distinctly. With all this, at the first examination it was impossible to produce diplopia, either with the aid of a red glass or prisms, &c., the images of first one eye, then the other were always seen by turns. A few days later, on repeating the examination, double images were perceived, they were homonymous with slight difference in height (image of the right eye lower), the lateral displacement is corrected by a prism of 28°. Micropsia of one image was also perceived. On both sides the outward movement is rather difficult. Full visual acuity on both sides—in the first examination slight myopia - ·75 D. is specified, afterwards emmetropia. The visual disturbance was removed by goggles with faintly ground glass on the right side—preparations of iron, bromide salts, shampooing with cold water and electricity were used. In six weeks' time binocular single vision was again restored; the facultative divergence = 0. With red glass and vertically deviating prisms homonymous diplopia corrected by prism 3°. Field of vision and sense of colour remained normal throughout.