Among the matters of interest which were brought before the British
Medical Association, at the recent Glasgow meeting, was an account by
Mr. Brudenell Carter of a method which he had devised of opening the
sheath of the optic nerve behind the eye, for the relief of pressure
within this sheath and within the cavity of the skull. The brain is
invested by firm membranes, which secrete a certain amount of fluid
and are continued down to the eye in the form of a sheath which
surrounds the optic nerve; and, whenever the pressure within the
cavity of the skull is increased, as by the growth of a brain tumor,
or even by excess of secretion from the membranes themselves, a
superabundance of fluid is apt to find its way down the nerve sheath
to the level of the eye, to subject the optic nerve to injurious
pressure, and, in many cases, to destroy the sight. It not
infrequently happens that the pressure within the brain cavity may be
increased by temporary or curable causes, which, nevertheless,
continue in action sufficiently long to produce permanent blindness,
even although the patient may, in other respects, recover. In view of
these conditions it was suggested by Dr. De Wecker, of Paris, sixteen
or seventeen years ago, that it might be possible to open the optic
nerve sheath, and thus not only to relieve the nerve from pressure and
to preserve it from injury, but also, on account of the position of
the eye relatively to the brain cavity, to drain the latter by
gravitation, and to relieve the brain as well as the eye. Dr. De
Wecker made two endeavors to accomplish this object, but he tried to
feel his way to the optic nerve without the aid of sight, and to
incise the sheath by means of an instrument carrying a concealed
knife, capable of being projected by means of a spring. The risks of
failure, and, still more, the risks of inflicting irreparable injury
upon the nerve, were such that he only attempted his operation in two
well nigh hopeless cases, and only one attempt to follow his example
has been recorded. Mr. Carter's attention was called to the matter
last year by a case in which the diminution of pressure within the
optic nerve sheath was manifestly desirable; and he devised a method
of operating by which the sheath could be exposed to view, and the
object attained with certainty, under the guidance of sight at every
step of the process.
He read before the Medical Society of London, last year, an account of
the first case in which he operated, which was successful; and he read
an account of three more cases at Glasgow, in one of which the result
was negative, as far as sight was concerned, while in the other two
the patients were not only quickly restored to useful vision, in one
instance from complete, in the other from nearly complete, blindness,
but were at the same time relieved or cured of other symptoms, such as
headache and sickness, arising from direct pressure on the brain. In
his paper at Glasgow, Mr. Carter claimed for the new operation that it
could be performed with certainty and without risk either to life or
to any important structure, and that it afforded a reasonable prospect
of the preservation of sight in many forms of disease in which it is
now habitually or frequently lost. As in the case of every new
operation, time and further experience of its effects are required in
order to determine the precise limits of its usefulness.
In the discussion which followed the paper, Mr. Bickerton, of
Liverpool, said that, in consequence of reading the account of Mr.
Carter's first case, he had himself performed the operation in two
instances, in one of which temporary restoration of sight was followed
by relapse, while in the second the ultimate issue was
favorable.--_London Times._
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