FIG. 1.—The whole worm. Portions of the testicles and alimentary canal
protruding through a rupture of the wall of the parasite.
FIG. 2.—The head of the worm.
FIG. 3.—The curved tail of the worm with its papillæ.
FIG. 4.—The ruptured part of the worm with protruding alimentary canal
and testes.]
Communication read at the Meeting of the Ophthalmological Society on
October 18th, 1894.
_Case of_ Filaria loa, _in which the parasite was removed from under the
conjunctiva._
By D. ARGYLL ROBERTSON.
(With Plate VI.)
On the 29th of June last I was consulted by Miss J. H⸺ on account of what
she termed the presence of a worm in her eye.
She is a slightly anæmic, prematurely grey-haired, but otherwise
healthy-looking lady, thirty-two years of age. She has resided at Old
Calabar on the West Coast of Africa at intervals, for nearly eight years
altogether. She twice had to return home on account of debility following
severe intermittent fever. During her last visit to Old Calabar, which
extended to about eighteen months, she suffered almost the whole time
from chronic dysentery followed by severe remittent fever, which
necessitated her return to this country last January in a very weak state
of health.
She stated that the worm was first observed by her in February of this
year, immediately after her return home. It frequented both eyes, but
showed a preference for the left one, sometimes coursing over the surface
of the eye under the conjunctiva, sometimes wriggling under the skin
of the eyelids—causing a tickling, irritating sensation, but not real
pain. It had latterly restricted its visits entirely to the left eye.
On account of the remittent fever from which she was still suffering,
her bedroom, when she first came home, was kept well heated, and until
she recovered from the fever she noticed that the worm was particularly
lively, occasionally causing the eye to become bloodshot, and the eyelids
to swell and blacken slightly. As long as she was confined to warm rooms
the worm was almost constantly moving about in the neighbourhood of the
eye, causing such irritation as to prevent reading or work of any kind.
This irritation with accompanying injection always passed off in the
course of the day, and never resulted in severe inflammation.
She thus found that the worm was sensitive to cold, coming to the surface
when the temperature was high, and disappearing to deeper parts when she
was exposed to cold. As soon as she had recovered strength so far as
to be able to go out of doors the visits of the worm to the eye became
fewer, perhaps a week or longer occurring between them. It usually put
in an appearance when she was near a cosy fire or in bed. Its last
disappearance was for two months, during July and August, and as she at
that time passed a worm _per rectum_ she thought she had thus got rid of
it. During these two months she was mostly in the open air, but as soon
as, in September, the rooms began to be heated, it again came to the
surface.
When I first saw Miss H—, in June, I very thoroughly examined the eye,
but failed to observe any trace of the parasite, unless perhaps the
appearance of a minute bluish vesicle at the extreme outer angle of
the conjunctival cul-de-sac corresponded to one of the extremities of
the worm, but the vesicle, though watched for a time, did not alter in
position or appearance. I gave her strict injunctions to return at any
time whenever she felt the worm on the move.
I saw her twice at the eye wards of the Royal Infirmary about the
beginning of July, but on these occasions careful inspection was again
negative in its results.
On the 12th of September, however, she again came to the Infirmary,
stating that she had felt the worm moving about in the left eye that
forenoon, and to prevent it leaving the surface she had kept the eye
well covered with a warm cloth till she made her way to the Infirmary.
On this occasion, after examining the eye for a minute or two, I observed
the worm moving in a tortuous, wriggling manner under the conjunctiva,
the surface of which became slightly elevated as it moved along.
It passed with a pretty quick movement over the surface of the sclerotic
at the distance of about 5 mm. from the outer margin of the cornea. It
glided from the upper outer towards the lower outer part of the globe.
There was increased lachrymation and slightly increased injection of the
conjunctiva,—just such an appearance as would result from a particle of
dust in the eye.
I at once placed my finger on the surface of the globe in such a manner
as to prevent the parasite passing backwards until the conjunctiva was
pretty well anæsthetised by the application of cocaine. I then got
my friend Dr. Maddox, who was present, to apply his finger while the
necessary preparations were hastily made for an operation.
She was placed on a couch and the speculum applied, when the pressure
of the finger having been removed the wriggling movements of the worm
were resumed, as briskly as before the application of the cocaine. I now
grasped with a pair of toothed fixing forceps a good fold of conjunctiva
over the centre of the wriggling worm, taking care to include in the fold
all structures superficial to the sclerotic. I next made with a pair of
scissors an incision through the conjunctiva a little nearer the cornea,
in such a manner as to lift up a small flap of conjunctiva, and after a
little careful separation of the tissues found one extremity of the worm,
which I seized with a pair of iris forceps. On now relaxing the fixing
forceps the parasite came away readily. No irritation or inflammation
followed the operation.
The worm presented the appearance of a piece of fishing-gut, being
round, firm, transparent, and colourless. It wriggled slightly for a few
minutes after removal while held in the forceps, but on being placed
in a solution of boracic acid, so as to prevent it becoming dry, it
seemed completely to lose its vitality. It measured 25 mm. in length and
barely half a millimetre in breadth. It terminated rather abruptly at
one extremity, scarcely tapering at all, but at the other it gradually
tapered to a pretty sharply curved fine point. Twisted round the worm,
and apparently attached to it near its centre, was a much finer, less
firm, transparent filamentous body, which I at first thought might
possibly prove to be a second young filaria, or even the male filaria,
but which on further careful microscopical examination appears to be
the alimentary canal of the worm protruded through an opening in its
musculo-cutaneous wall, caused by the forcible grasping of the parasite
with the forceps.
The worm after removal was, on the suggestion of Dr. Muir, Pathologist
to the Infirmary, placed in a mixture of equal parts of glycerine and
methylated spirits, but the cork of the bottle in which the mixture was
put had retained some of the blue colouring matter (methyl violet) of
a solution previously in the bottle, and thus the preservative mixture
became faintly blue-tinted. The parasite absorbed the colouring matter
slightly, but the filamentous body projecting from it absorbed it more
freely, becoming markedly blue-tinted. After remaining in the solution
between three and four weeks the parasite was carefully mounted as a
microscopic preparation in glycerine jelly by Mr. Simpson, assistant
keeper of the University Anatomical Museum.
It is not my intention to attempt an account of the natural history
of the parasite, as I propose to submit the specimen to some special
authority in that department.
I have had some sketches of it made by a competent artist, and these, as
well as the preparation itself under the microscope, I have pleasure in
exhibiting to you.
It appears to me not improbable that this specimen may be found to supply
what has hitherto been a missing link, namely, the male animal.
Since writing this I have had the opportunity of submitting the specimen
to Dr. Munson, who at once recognised it as the male worm, and has
undertaken to make a careful microscopical examination and description of
it.
“_Report by DR. MANSON on the structure of the_ Filaria loa,
_from an examination of the specimen removed in the foregoing
case, as well as of the specimen of the same parasite exhibited
at a meeting of the Society on January 31st, 1895. The latter
filaria was removed from the eyelid of a patient by Dr. J. R.
Logan, Liverpool._—
[Illustration: FIG. 1.