DEMENTIA.—In chronic dementia Albutt found either hyperæmic or atrophic changes in the disc in 23 out of 38 cases. Noyes271 found hyperæmia in 18 cases, and infiltration of the optic nerve and retina in 12. Jehn and Klein were unable to find changes in the discs of any of the cases which they examined.
271 Idem.
MANIA.—Albutt found the discs hyperæmic except in one case examined during a paroxysm, in which they were pale. Out of 20 cases of acute mania, Noyes272 found 14 which showed hyperæmia of the discs; the discs of the remaining 6 were either anæmic or normal, these latter cases all being of short duration (less than three months); the 6 cases of chronic mania had eye-grounds which showed no lesion, while the other 3 exhibited hyperæmic or inflammatory changes.
272 Loc. cit.
MELANCHOLIA.—In Noyes's examination 4 out of 5 cases had healthy eye-ground, and 1 moderate hyperæmia and striation. Jehn found hyperæmia in every one of 40 cases examined, 2 of these having decided neuritis, which he supposed to be due to meningeal change.
Spinal Cord.
INJURIES TO THE SPINE.—Physiologists have frequently shown that pupillary and other eye-symptoms may be produced by experimental injury to the spinal cord of animals, which would lead us to naturally expect analogous results in man in cases of spinal fracture and injury. This subject has received great attention in England, where spinal injury from railway accidents appears unusually frequent. Albutt273 tells us that it is tolerably certain that disturbance of the optic nerve and its neighborhood is seen to follow disturbance of the spine with sufficient frequency and uniformity to establish the probability of a causal relation between the two events. Erichsen,274 who has collected his large clinical experience into a book on Concussion of the Spine, after citing Plutarch to show how Alexander the Great was in danger of losing his eyesight from the blow of a heavy stone on the back of the neck, gives 53 cases (not tabulated with this view by the author), of which 49 were apparently undoubted cases of spinal injuries: of these, 13 (36 per cent.) showed decided eye-symptoms. Erichsen says: "My experience accords fully with that of Albutt. I found that in the vast majority of cases of spinal concussion unattended by fracture or dislocation of the vertebral column there occurred within a few weeks distinct evidence of impairment of vision." As enumerated by this author, these symptoms consist of difficulty of seeing in dim light, blurring and running together of the letters, and at times (in the early stages) slight diplopia. Later, there is photophobia, with contraction of the brow, which gives a peculiar frown, and at times an injection of the conjunctiva; these symptoms often being accompanied by muscæ volitantes and photopsia. He agrees with Albutt in attributing these to an ascending meningitis, while Wharton Jones considers that the eye symptoms are better accounted for by the action of the cilio-spinal centre and the sympathetic filaments springing from the dorsal and cervical cord. Wharton Jones275 lays stress upon the undue retention of after-images and upon the small amount of comfort which a positive (convex) glass gives the patients, and "to the pain extending from the bottom of the orbit to the occiput, which is always a symptom belonging to deep-seated disturbance in the circulation of the optic apparatus." Rondeau276 gives an interesting example of severe affection of the eyesight from apparently slight injury to the spine. The patient, seventeen years old, fell on the staircase, striking the neck and shoulders. There was complete loss of sight. Light-perception returned in a month, and four years after he could distinguish large objects in front of him, but vision remained stationary at that point. Albutt informs us that the percentage of visual affections is greater in proportion to the height of the seat of the injury in the spine.
273 Use of the Ophthalmoscope, London, 1871.
274 Concussion of the Spine, by John Eric Erichsen, London, 1875.
275 Failure of Sight after Railway and Other Injuries of the Spine and Head, London, 1869.