Shell-shock: Functional blindness (monosymptomatic).
Case 433. (Crouzon, January, 1915.)
A shell burst above the head of a sergeant in a battle near Neuf château, August 22, 1914. The man was kneeling at the time; felt a terrible shock, slipped prone, lost consciousness and woke in the evening blind. Next day he could hardly distinguish light from dark. Yet the light reflexes were normal; the fundus was normal.
This Crouzon calls the symptomatic triad for functional nerve blindness of Dieulafoy. There have been similar cases following eclipse of the sun and nervous shock. The eclipse cases suggest that the bright flash might have something to do with the sudden blindness (yet blindness has appeared in cases in which the shell burst behind the patient).
The diagnosis of temporary blindness, with a prognosis of early recovery, was made. The neurological examination was normal.
For its suggestive effect, glycerophosphate injections and progressive reëducative measures were adopted. The patient was shown that he could see, first, the contour of objects, then details and colors, then large letters and later small letters. In a month the blindness was almost well. Five months afterwards there was still a certain haze over the field of vision and a slight difficulty in distinguishing certain colors.
Jousset states that aside from visual alterations as the result of cranial trauma, and aside from various transitory amblyopias such as scintillating scotoma, the main varieties of amblyopia are:
First, Congenital amblyopia.
Second, Amblyopia due to cerebral intoxication.
Third, Retrobulbar neuritis and toxic amblyopia.
Fourth, Amblyopia ex anopsia.
Fifth, Hysterical amblyopia.
The most frequent amblyopias among the soldiers are exanopsia. Aside from a few amblyopias caused by prolonged occlusion of the eyelids, ptosis, or blepharospasm, the most frequent are due to opacities, ametropia, and strabismus. The hysterical amblyopias are, as a rule, associated with blepharospasm due to intense photophobia, and are sometimes associated with constant lacrimation. Vision at a distance is poor. The patient succeeds in reading but shows an asthenopia of fatigue. The cornea and the conjunctiva are anesthetic, and sometimes the eyelids also,—the so-called anesthesia en lunettes. The pupils are large but react properly. The patient complains of many species of disorder; loss of the sense of the third proportion, micropsia, megalopsia, diplopia, erythropsia, diplopia in two colors, inverted image, hemierythropsia, rotatory amblyopia. There is concentrated limitation of visual fields, exaggerated by fatigue and by intense light; reduced in dim light or when the patient is provided with smoked glasses; enlarged upon the instillation of atropin or with convex glasses. As a rule, with unilateral amblyopia, the functional disorders start in binocular vision. Practically the most important diagnostic feature is the anesthesia, since this cannot be readily simulated. Sometimes corneal anesthesia is found in non-hysterical persons, who may perhaps be regarded as potential hysterics.