James Pleasant Parker.

Annals of ophthalmology and otology online

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the cornea on the nasal side of the radius of the sphere, this
ray is made to converge less toward the middle ray than
before refraction ; striking the cornea on the upper side of
the radius of cylindrical curvature, it is also refracted upwards.
Following this ray to the retina we find it impinging above the
horizontal^ and on the temporal side of the vertical^ meridian.
A line drawn through these three points of impingement will
locate the image of the line (arrow) looked at. It is inclined
in obedience to the law of refraction that a ray of light in
passing from a rarer into a denser medium must be refracted
toward the perpendicular at the point of impingement.

There is one other objection which Dr. Hotz brought for-
ward, viz: While a concave cylinder held obliquely in front
of an eye at some distance will make horizontal and vertical
lines appear inclined towards its axis, this inclination grows
less and less as the eye is approached, and, as he thinks, disap-
pears entirely when the cylinder is brought into contact with
the cornea. This is all easily explained. Take again the
three axial rays in a horizontal plane. Striking the horizontal
portion of the oblique cylinder, the middle ray passes through
unrefracted and continues in the same plane, while one of the
outer rays is made to deviate downwards, and the other
upwards. For convenience of study we will say that the
deviation of each ray is 2"^ from the horizontal plane. This
deviation continues the same until the retina is reached,
regardless of whether this distance is 1 m. or 25 mm. In
obedience to the law of direction the horizontal line is made
to appear to incline more when the cylinder is held 1 m. from
the eye than when it is held 60 cm, away. In obedience to the
same law the line appears less and less inclined as the oblique
cylinder is made to approach still nearer the eye, but even
when brought into contact with the spherical cornea, its inclina-
tion does not and cannot disappear entirely, though often one



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316 THE OBLIQUE MUSCLES.

may not be able to perceive that there is still an inclination.
This apparent change in the direction of a line viewed through
a concave cylinder held obliquely, as it is moved from arm's
length to the eye, could not be explained if Helmholtz* law of
direction were true. If ihe axial ray were the line of direc-
tion, the apparent obliquity of a horizontal line would be the
same whether the cylinder causing the phenomenon were held
at arm's length or in contact with the eye, for the reason that,
after the axial rays are deflected, some above and some below
the horizontal plane, they pursue a straight course to the retina
whether it be far away or near by. These rays prolonged,
according to Helmholtz, would locate the source of the light,
and necessarily would give it the same apparent inclination
for all distances at which the cylindrical surface might be
held from the eye. Not so with that law of direction which
says that all lines of direction are radii of retinal curvature
prolonged. This law makes it necessary for the line to appear
to incline more when the cylinder is held far away from, and
less when it is brought close to, the eye.



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A CASE OF GLIOMA OF THE RETINA. 317



NOTES OF A CASE OF GLIOMA OF THE RETINA.

By Alfred J. Horsey, M. D., M. N. C. S., Eng.
M. R. C. S., Edin.

OF OTTAWA, ONT., CANADA.

SURGEON TO THE EYE AND EAR DEPARTMENT OF THE COUNTY OF CARLETON
GENERAL HOSPITAL, OTTAWA.

JANE A., 4 years of age, the fifth child of a healthy family of
six children. Father and mother healthy; no history of
miscarriages. Two years ago she would occasionally awaken in
great fright screaming and apparently would not know or be
pacified by her parents. Had convulsions. With this exception
her health was good. Six months ago a grayish yellow appear-
ance was first noticed behind the pupil in the left eye.

On April 7, 1894, she was kindly referred to me by Dr.
McKay, of Manotic, when the appearances in the eye were as
follows: That which first attracted attention was a yellowish gray
mass shining behind the dilated pupil, which could be easily seen
with the unaided eye. It had a consistent look, and smooth, uneven
surface, upon which there were no vessels. It half filled the
vitreous chamber and appeared to proceed from the nasal side.
The anterior chamber was shallow from pressure from behind ; the
iris was of the same color as the other; the pupil was dilated, but
regular, reflex absent. The ciliary border was darkly congested
by enlarged blood vessels, chiefly veins. Other blood vessels at
the inner and outer canthus more superficial ran horizontally,
the cornea and lens were clear. Tension + 2. Vision nil. Lids
slightly edematous ; no proptosis ; no increase of corneal curvature ;
movement of globe normal; right eye normal. Immediate eneu-
cleation was advised.



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318 A CASE OF GLIOMA OF THE RETINA.

She was again brought to me on April i6, nine days after
the first visit. The ciliary border was more prominent and more
vascular, while the corneal curvature was increased and cornea
steamy, with loss of luster. Tension about the same as before:
+ 2. Had occasionally cried, complaining of her head, the past
two days.

April 1 8. Enucleation under chloroform; globe filled orbit so
that it was with difficulty prized out intact. Nerve divided well
back, looks healthy. A dark granular suspicious looking substance
was removed from the upper part of orbit. Patient made a good
recovery from the operation and remained in fair health up to
July, three months after operation, when she began to fail. The
orbit became full and the lids distended by a growth behind
them, which gradually became more and more projecting until it
protruded 2^4 inches in a cylindrical form with a tuberous summit,
granular, and oozing an icherous pus and blood (fungus hema-
todes). The skin about the orbit was made to bulge forwards, the
veins in which were greatly enlarged. She slowly declined during
the remaining months of the year, being convulsed several times,
until December 24, when she died — fourteen months after the
discovery of the disease and eight months after operation. The
right eye remained unaffected.

REMARKS.

I have thought the foregoing case sufficiently important for pub-
lication, not only as glioma is an uncommon disease and the only
neoplasm which occurs in the retina, but on account of symptoms
which would tend to confound it with pseudoglioma, which would
materially modify the prognosis. Glioma is a growth from the
neuroglia, and has its origin only in nerves or the nerve centers.
It consists microscopically of small round cells, sometimes with
spindle cells within a delicate stroma, securing very large neuclei.
It is a disease almost exclusively of children, sometimes noticed at
birth and frequently a few weeks or months afterwards. Though
a rare disease, Messrs. Lawford & Collins (^Royal Lond, Hosp,
Ophth» Reports^ 1890) publish sixty cases, fifty-five of which were
cases in Royal Hospital during the years from 1871 to 1890, in
connection with which many instructive points have been brought
out. According to these observers, during the first two years of
life is the period in which it oftenest shows itself. The disease
may be bilateral, affecting both eyes simultaneously or within a
short interval. The right and left eyes are about equally affected
as also are the sexes.



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A CASE OF GLIOMA OF THE RETINA. 319

Recoveries after enucleation are rare, even where the limit of
three years is regarded as being such, the percentage being as low
as 12% to 15%. Recurrence is the rule in a great majority, which
terminate fatally in a few months. From the literature of tl\e
subject recoveries seem to bear little relation to the age of the
patient, nor, strange to think, by the length of time between detec-
tion and removal. For example, in a case of undoubted glioma
there was no return after nineteen years, disease was detected at
2 years of age and was not operated on till one and one-half years
later.

Diagnosis in advanced cases may be made with tolerable
certainty, but in their beginning, if then detected, diagnosis is
uncertain and difficult. The microscope alone can decide its real
character. That often while it is most difficult to differentiate, it
is pseudoglioma, which does not mean any particular and definite
pathological condition, but any resembling glioma which might be
mistaken for it. The difficulty of diagnosis may be more readily
estimated when it is known that of twenty-four eyes removed for
supposed glioma retina; at the Royal London Ophthalmic Hospital
(Moorfields), whereon a consensus of opinion of wide experience
was brought to bear, notwithstanding which, seven subsequently
by microscopic examination showed a mistaken diagnosis. Other
conditions likely to be confounded with glioma are persistent fetal
conditions, notably persistency and potency of the hyaloid artery,
causing excessive and maldevelopment of the lens capsule. Also
concretions of tubercle in the choroid. Detachments of the retina
from other growths, or the products of ophthalmitis.

In the above reported case the cerebral symptoms preceding the
disease in the eye, viz., the startling cry out of sleep and con-
vulsions, which were indicative of meningitis, rather pointed to
pseudoglioma than true glioma, the latter of which a microscopic
examination proved it to be.

There was not at any time middle-ear disease or a purulent
discharge from the ears.



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320 A NEW ARTIFICIAL EYE.



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A NEW ARTIFICIAL KYK.



321



and to cement this with Canada balsam (of the same refractive
index as glass) to a block of the same glass as the accompanying
illustration shows. The length of the block of glass must be such
that its posterior surface coincides with the posterior focal plane
of the eye, which means that the distance from anterior surface of
cornea to retina must be r + -Jl, = 8.20 + 1549 = 23.69 mm.
The j>osterior focal distance of this new reduced eye is therefore
23.69 mm. But as it is almost impossible for the manufacturer to
exactly obtain this distance of 23.69 mm.^ and as it is further
desirable that the eye should be made longer or shorter to repre-
sent the axial changes of the human eye, a prism of glass (of 10°
angular aperture) is brought in contact with the posterior surface
of the eye, the plane of which has been ground off obliquely, so




that it makes an angle of 80° with the optical axis of the eye. For
the addition of the prism again produces a surface, which is always
at right angles to the optical axis ; while by pushing the prism
along the posterior surface of the glass block the eye can be made
longer or shorter without the introduction of air.

A scale has been added, which exactly indicates the refractive
condition of the artificial eye. This scale is calculated with this
supposition, that the refraction is reckoned in the same way as in
our own eye, namely, from the anterior focal point of this eye,
which lies 15.49 mm. in front of its cornea. Now the scale can
be easily calculated just as in the human eye ; for in such a system
of an eye with axial emmetropia and correcting lens at its anterior
focal point the absolute values of the anterior and posterior focal
distance remain the same as in the emmetropic eye, and so, also,
does the distance of second nodal point from retina or second
principal focus, but this nodal point is displaced to the same extent
as the second principal plane, namely, by — ^p^ mm.^ where
F 1 and F 2 refer to the anterior and posterior focal distances of the
eye, and f indicates the focal length of the lens, used at the



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322 A NEW ARTIFICIAL EYE.

anterior focal point of the eye to correct the axial ametropia. In
our new eye we have Fi = i5'49 ^^' and Fa = 23.69 mm.^ and
if we now take f as equal to 1000 mm,^ j. e,^ if we take a lens of
I dioptry, we find that the axial lengthening of our new eye, to
be corrected by a glass of i D., must be — ^o"(j" - ^^' = — o-S^T
mm. If, therefore, we displace the retina of this eye in the direc-
tion of the optical axis by 0.367 mm, we obtain a difference of
refraction equal to i dioptry. This is almost exactly the same as in
the human eye, or rather in the average eye of Helmholtz, where a
displacement of the retina equal to 0.321 mm, gives a difference
in refraction equal to i D. But as in the new eye the prism is
moved obliquely it takes more than 0.367 mm, in the direction
of its movement to get 0.367 mm, in the direction of the
optical axis. A little calculation shows that the prism must be
moved by ^^ = 2.1 mm, for each dioptry. The posterior surface
of the prism consists of ground glass, so that we may observe the
retinal images of objects which are now of the same size as in the
human eye.

By making the eye ametropic we may observe the images of
ametropic eyes, which will appear in diffusion circles of about the
same size as in the human eye. The diameter, </, of the diffusion
circle in the new eye for axial ametropia equals: d ^= p i^* (^^)-
where p is the diameter of the artificial pupil, Fi and Fj the anterior
and posterior focal distances of the new eye, m the "distance of
pupil from cornea and D. the refractive value of the glass which
would correct the ametropia. The diameter (di) of the diffusion
circles of the schematic human eye according to NageP is
di == l^aS? where Fi is the anterior focal distance of the human
eye and p and D have the meaning before given. Now as the
ratio of *j = j."^ as Fi of our artificial eye = Fi of the human
eye, by construction, we see that the diffusion circles are slightly
larger in the new model, but not very much. For example an
axial myopia of i dioptry gives in the schematic eye a diffusion
circle of 0.06 ww., while that of the new eye is 0.07 mm.

The ametropia may be corrected by a lens in front of the stop,
which indicates the anterior focal plane of the model. There is
besides a spring at the back, which allows any picture of the
fundus to be brought in contact with the prism, where it can be
viewed with the ophthalmoscope at the stop. In this manner the
eye may be employed for ophthalmoscopy^ skiascopy and eidoscopy^
if I may be allowed to coin a new term for the act of observing

^Die Anomalien der Refraction^ Graefe and Saemisch, Ca^itci X,^ p. 467^



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A NEW ARTIFICIAL EYE.



323



the images produced by this eye. The scale will be very useful
to check the observer. This eye may also be employed to obtain
a correct idea about the size of a scotoma in a patient's eye; for
all that is necessary is to bring the new eye at the place of the
patient's eye, when the image of the boundary of the scotoma,
which must have been marked off in a black wall before, will
appear of almost the same size as it is in the patient.

Let us now compare the new eye with that of Helmholtz :



The Schematic eye of
Helmholtz has:


New Reduced Eye
of Glass has:


Difference,


Cornea = 7.8 mm.


Cornea = 8.2 mm.


-f 4 mm.


Anterior focal distance
= 16.6 mm.


Anterior focal d]«tance
= 16.6 mm.


mm.


Distance of anterior focal
point from cornea = 13.7
mm.


Distance ot anterior focal
point from cornea = 15.5
mm.


+ 1.8 mm.


Distance of posterior focal
point from cornea = 22.8
mm.


Distance of posterior foral
point from cornea =
23.7 mm.


+ 0.9 mm.


Distance of second nodal point
from retina = 15.5 mm.


Distance of nodal point
from rf tina = 16.5 mm.


0.0 mm.


Axial lengthening or shorten-
ing required to produce an
ametropia of 1 dioptry as
measured by a glass at ante-
rior focal point of eye =
0.821 mm.


Axial lengthening or short-
ening required for the
new eye under the same
conditions = 0.367 mm.


+ 0.046 mm.


Length of eyeball from ante-
rior surface of cornea to
posterior surface of sclera
= 22.8 + 0.9 mm. = 23.7 mm.


Length of eyeball from
anterior to posterior sur-
face = 23.7 mm.


0.0 mm.



From the table it will be observed that this new eye in more
than one respect differs very little from the schematic eye of
Helmholtz, but that as far as the size of the retinal image is con-
cerned it is exactly like it. In short it is a reduced eye in glass.
The advantages which this eye offers over other ' artificial eyes
are the following:

1. It gives images of the same size as the average human eye.

2. It may be used for ophthalmoscopy, skiascopy or eidoscopy.

3. It gives a good idea about the small change in the length of
an eyeball that is necessary to produce axial ametropia.*

*Thi8 artificial glass eye may be obtained from Messrs. Queen & Co., of



Philadelphia, who have taken great pains
possible.



in making it as accurate as



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324 SARCOMA OF CHOROID.



SARCOMA OF CHOROID.

By Alfred J. Horsey, M. D., M. N. C. S., Eng.,
L. R. C. P., Edin.

OF OTTAWA, CANADA.

SURGEON TO THE EYE AND EAR DEPARTMENT OF THE COUNTY OF CARLETON
GENERAL HOSPITAL, OTTAWA.

HW., a well-grown, healthy looking lad, i6 years of age,
• having a good family history and no noteworthy personal
history, consulted Dr. James Grant, in February last, on account
of a smooth pultaceous tumor about the size and shape of the
lateral half of a hen's egg, situated on the radial border of his
right forearm, just above the wrist joint, which was opened and
found to contain pus ; there was also swelling and redness of the
index, middle and ring fingers of his right hand at the roots of
the nails, causing them to be clubbed, and which afterwards sup-
purated. In the front part of his left eye something abnormal
was seen, which had been discoved by his friends some three
weeks before, and on" which account Dr. Grant kindly referred
him to me.

On February 13, when I first saw him, a yellowish, well-defined
body, 3 mm. square, having a smooth surface, was clearly seen in
the front part of the left eye, which, at first sight, resembled an
abscess in the cornea, but on closer examination with a lens was
found to be a new growth in the anterior chamber, situated in the
angle between the cornea and iris, extending horizontally inwards
from the root of the iris on the temporal side, halfway across it
towards the pupil, in a slightly radiating manner. Minute blood
vessels running horizontally could be seen in its semi-translucent
substance. The periphery of the iris was slightly dragged upon
giving the impression that the growth came from behind it. The



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SARCOMA OF CHOROID. 325

pupil was slightly larger than its fellow and sluggish to light; the
ciliary zone was congested. R. V. = J ; L. V. = ^\. Tension
slightly increased. Ophthalmoscope — Fundus reflex indistinct
by direct method only ; large vessels were obscurely sefen in the
fundus, for a short distance, then lost in darkness.

February 15. Two days later vision had so far diminished that
he could barely read ^%. Tension as before. A disc of homat-
ropin and cocain only slightly dilated the pupil. His eye caused
him no pain, and only slight inconvenience, though vision was so
greatly impaired.

The diagnosis, ** sarcoma,*' found at his first visit, was further
strengthened at his second, and immediate excision of the eye
advised. He was recommended to get another opinion before the
operation, which he did, and which coincided with my own. The
eye, however, was not excised until a month later, when a micro-
scopic examination confirmed the diagnosis of sarcoma. The
patient made a fair recovery from the operation, but after a couple
of weeks rapidly lost flesh, became cachectic, complained of dizzi-
ness, and a few days before his death, which occurred on May
5, he had several attacks of right-sided spastic convulsions. No
post-mortem was obtained. Probably the cause ol death was
extension backwards by continuity from the choroid to the pia
mater and involvement of other organs by metastasis. The temper-
ature was not much disturbed and showed no great fluctuation.
The other (right) eye was not affected.

The case is instructive in several particulars. Sarcoma of the
choroid being a disease of retrograding adult life, occurring most
frequently beyond the age of 50, the youthfulness of the patient
makes it a rare exception.

Sarcoma of the choroid being a disease of adult life, contrasts
strongly with glioma retinae, another intra-ocular malignant growth,
occurs almost exclusively in early childhood. That it was without
pigment, which is exceedingly uncommon in growths in this highly
pigmentus covering. That it was so rapidly fatal — its duration
being measured by months rather than years — two years being the
average length of life in fatal cases. Prognosis is not nearly so
unfavorable as in glioma retina? , where recovery is rare. In sar-
coma the mortality, according to several high authorities, is about
50%, 32% being from metastasis to distant organs. That it was
idiopathic ; no injury or previous disease in the eye, as is often the
case. That it was unattended by pain.



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326 THE MUSCULAR BALANCE OF THE EYES.



A CASE ILLUSTRATING THE RELATION BETWEEN

THE MUSCULAR BALANCE OF THE EYES AND

THEIR REFRACTIVE CONDITION.

By C. E. Norton, M. D.,
lewiston, maine.

OPHTHALMIC SURGEON TO THE CENTRAL MAINE GENERAL HOSPITAL.

MISS E. P., a Student in Normal School, 20 years of age,
consulted me August 23, 1893, in regard to her eyes. She
was in good general health. She had a noticeable convergent
Strabismus in the right eye. Vision in right eye = f g, in the left
eye = |g.

She had been wearing for several months a pair of — 1.25 D.
spherical spectacles which she had obtained from a prescribing
optician. The use of these spectacles caused the strabismus to
disappear, but it returned almost immediately on removing them.
She did not wish to have an operation performed, but she wished
me to prescribe for asthenopia from which she suffered severely
when studying.

I found that she had hyperopic astigmatism which could be
corrected by + 0.25 D. cylinder axis 90°, both eyes. I prescribed
these lenses for constant use. With them her vision was JJ in
each eye. With the aid of these spectacles she was able to finish
her course of study, and she graduated from the school in the
spring of 1894. Since graduation she has been teaching in a city
school. She called at my office March 23, 1895, ^^^ stated that
if she wears the glasses constantly she has no return of the stra-
bismus, and is able to do her work without discomfort in her eyes.
Going without the glasses causes the strabismus to return after a
time.



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THE MUSCULAR BALANCE OF THE EYES. 327

The above case has several points of interest. It will be noticed
that the vision was good in both eyes, and that in the squinting eye
it was but very little less than in the other eye. There was no
marked amblyopia to account for the strabismus, and we have
every reason to believe that in this case the sole cause of the
strabismus was the optical error, acting on an overworked eye ;
the natural relation between convergence and accommodation pro-
ducing the result. When this relation was disturbed, by the use
of concave glasses, increased convergence ceased to give the same
assistance to the power of accommodation, which it did before,
and the convergence disappeared.

The case is interesting on account of its rarity. Cases are
sometimes seen where strabismus exists, accompanied with, and
probably caused by optical error in which the strabismus entirely
disappears, from no other treatment than the use of properly fitting
spectacles.

I have never seen a case before, nor do 1 remember of reading
of one, where a strabismus caused by hyperopic astigmatism, was
made to disappear by the use of concave spherical lenses.

The case is also of interest by being a positive contribution for
the solution of the quewstion which has been under discussion for
the last few years: ''Are weak lenses of any value?" It is
evident that in this case weak lenses were of great value, as they
relieved the asthenopia, and, what is of more importance, the
strabismus, without any operation being performed.



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328 THE QUARTER DIOPTRV CYLINDER.



THE QUARTER DIOPTRY CYLINDER— SOME
TESTIMONY FOR.

By E. E. Hamilton, M. D.,
of wichita, kan.

THAT the complexity of symptoms known under the general



Online LibraryJames Pleasant ParkerAnnals of ophthalmology and otology → online text (page 29 of 56)