ELEGTRO-MAGNETISM 
In Ophthalmic Surgery. 
WITH ILLUSTRATIVE CASES. 
Read before the Tri-State Medical Association of Mississippi, 
Arkansas and Tennessee, 
BY A. G. SINCLAIR, M.D., 
Professor of Ophthalmology, Otology and Laryngology, Memphis Hospital Medical College 
Surgeon-in-Chief to the Eye, Ear and Throat Department of St. Mary's Hospital 
and Dispensary, Memphis, Tenn.; formerly Resident-Surgeon 
of the New York Eye, Ear and Throat Infirmary; 
member of the International Medical 
Congress, etc. 
[Reprint from the Mississippi Valley Medical Monthly.] 
MEMPHIS : 
5'. C. Toof & Co., Printers and Lithographers. 
1887. Electro-Magnetism in Ophthalmic Surgery, 
WITH ILLUSTRATIVE CASES. 
As the cases in which the magnet may be employed with 
advantage as frequently fall into the hands of the general 
practitioner as into those of the specialist, and as, moreover, 
its early employment contributes greatly to success in its use, 
it occurred to me that a brief article on this subject would 
interest the Society. 
Although it is long since the magnet was first employed 
in surgery ; for example, by Fabricius Hildanus in the seven- 
teenth century, by Milles and others in the eighteenth, and 
by still others later on, its use was very limited and of the 
crudest fashion until 1873. In that year Dr. McKeown of 
Belfast employed it successfully in a series of cases, in which 
fragments of steel or iron had been driven into the eyeball. 
These he published in 1874, and from that time the magnet 
has been considered one of the most valuable agents at the 
command of the ophthalmologist. 
Two forms of the instrument are in use-the simple (bar) 
magnet, and the electro-magnet. The former was that em- 
ployed by Dr. McKeown ; the latter is, however, much more 
powerful, and is therefore preferred by the majority of oper- 
ators, as it admits of the use of extremities more slender, 
and hence better adapted for introduction within the eyeball. 
Moreover it is sometimes an advantage to render the extremity 
magnetic only at, or immediately before, the moment of con- 
tact with the foreign body, and this the electro-magnet 
enables the operator to do. The polar extensions being de- 
tachable, a broader surface and more powerful tractive force 
can be employed at will, or an extension adapted to the case 4 
ELECTRO-MAGNETISM IN OPHTHALMIC SURGERY. 
in hand substituted, llirsliberg of Berlin was probably the 
first to employ this form of the instrument in ophthalmic 
surgery. 
Although the magnet may be an aid in the removal of 
fragments of steel or iron from the superficial structures of 
the eye, it is in the extraction of those which have passed 
into the interior of the organ that its great advantages are 
most strikingly displayed. In the cornea these foreign bodies 
are generally too firmly embedded to yield to the power of 
the magnet, and are more easily acted upon with the scoop, 
spud, and other instruments. A similar difficulty is ex- 
perienced when the object is lodged in the firmer structures 
of the interior, as the iris, ciliary body, choroid, optic papilla, 
retina, or even the crystalline lens, but even from most of 
these tissues the removal of fragments has often been effected, 
and where the resistance to be overcome is mainly that offered 
by the vitreous, which is easily broken up, or the aqueous 
humor, the action of the magnet is available, and renders 
the extraction of visible particles almost a certainty, while 
that of even those that cannot be seen can generally be 
effected by a skillful operator. The advantage of searching 
in the interior of an eyeball for an object with an instrument 
that will attract and adhere to it, over the same process with 
one possessing no such property, as operators were compelled 
to do several years ago, is very apparent, and many eyes are 
now saved which in those days would have been condemned 
to enucleation. 
In regard to the manner of using the electro-magnet, I 
would premise by saying that the instrument, as applicable 
to the eye, is by no means one of great power, and it is there- 
fore necessary to make a passage for it up to, or very nearly 
to, the object to be attacked ; even the coating of lymph, 
which soon covers a foreign body in the vitreous humor, ELECTRO-MAGNETISM IN OPHTHALMIC SURGERY. 
5 
will materially interfere with the influence of the magnet. 
Nor is the latter always sufficiently powerful to prevent the 
lips of a very limited wound from brushing the adherent 
intruder from the magnet during its withdrawal. It is there- 
fore well, unless the original wound is recent and ample to 
obviate this danger, to make a new passage by incising the 
cornea or sclerotica, as the case may be, selecting for this 
purpose of course the point from which the extraneous sub- 
stance can be most easily reached. Except in the case of very 
small bodies it is often an advantage to make the incision T 
shaped, as in this form it affords more ready exit and lessens the 
liability to detachment of the object from the magnet during 
withdrawal. The scleral wound should be closed with sutures, 
otherwise before making it a flap of conjunctiva should be 
dissected up in such a manner as to form a cover for the 
scleral incision, in which case sutures in the conjunctiva will 
be sufficient. 
The magnet may also be used as an aid to diagnosis in 
doubtful cases, as when a particle within the eye is seen but 
its nature is uncertain, or in the case of a similarly situated 
mass of lymph which may contain a piece of iron or steel. 
When a powerful magnet is placed near the eye such objects 
will be seen to move toward it. It may also be employed in 
the case of invisible fragments of iron in the eyeball. A sus- 
pended magnet placed near an eyeball which contains apiece 
of iron or steel will move toward the point at which the 
latter is situated under the same influence of course which 
attracts the iron to it. In this way the presence of steel or 
iron has been repeatedly detected. This was shown by Dr. 
Pooley of New York who, acting upon this principle of 
mutual attraction, made a series of experiments upon enucle- 
ated eyes, and eyes of the lower animals, into which portions 
of steel had been thrust, and using as his magnet a magnetized 6 
ELECTRO-MAGNETISM IN OPHTHALMIC SURGERY. 
sewing needle suspended by a silk thread. Pooley increased 
the power of his magnet by rendering the fragment in the 
eye also magnetic ; and this may also be done with advantage 
in the human eye, by passing a galvanic current through the 
organ, or by induction. The value of the magnet as an aid 
to diagnosis is not new to general surgery, the magnetic 
needle having been employed for the detection of fragments 
of steel or iron in tissues by Brodie and others. 
The following cases will serve to show in some measure 
what the electro-magnet can or cannot accomplish in the 
extraction of foreign bodies from the eye: 
W. J., engineer, was brought to me in March last with an 
injury of the eye, caused by a fragment of metal which flew 
from a piece of iron or from the hammer with which he had 
struck it. Near the center of the cornea was a wound which 
evidently extended entirely through this membrane, as the 
anterior chamber was much reduced in depth, the iris lying 
almost in contact with the cornea. Externally, at the seat 
of injury, nothing was visible but corneal tissue, but inter- 
nally, opposite the point of injury, there was seen through 
the uninjured portion of the cornea a minute black body 
projecting into the anterior chamber, which was evidently 
the interesting object of my search. It was so deeply em- 
bedded that it was apparent at a glance that its removal 
through the original wound would be very difficult if not 
impossible, and I determined to attack it from the inner sur- 
face, and to employ the electro-magnet. I was assisted in 
the operation by Dr. Overall of this city. The thorough 
application of cocaine utterly failed to produce anaesthesia, 
the only instance in which this has occurred in my practice, 
although I have used it many times in nearly all operations 
on the eye since its introduction, having been the first opera- 
tor in the South to employ the drug. Chloroform was sub- ELECTRO-MAGNETISM IN OPHTHALMIC SURGERY. 
7 
stituted, and a curved incision was made in the cornea near 
its periphery. Through this the electro-magnet was passed 
and onward to the site of the injury, and no doubt into con- 
tact with the metal, although the latter was then hidden from 
view by a coating of lymph. Its withdrawal failed, however, 
to bring away the foreign body. The attempt twice repeated 
yielded no better result. I then laid the magnet aside, and 
taking up a delicate pair of iris forceps passed it with closed 
blades to the point at which I believed the foreign body to 
be situated, and at the first attempt succeeded in seizing it 
and bringing it away in the bite of the forceps. Although 
the magnet had failed to dislodge the foreign body, it was 
with keen satisfaction that I saw the latter after removal spring 
to the magnet, thus proving its nature, and hence, that the 
little particle was the object I had sought. Rapid recovery 
followed with vision equal to reading print less than half 
the size of ordinary book type. This case illustrates and 
sustains what has been said regarding the inability of the 
magnet to extract fragments which are at all firmly em- 
bedded in the denser tissues of the eyeball. 
J. G. 0., foreman in a machine shop, was sent me from 
Mississippi in August last. On the day preceding his arrival 
he was struck on the eye by a fragment from a steel hammer. 
He had had no pain, the eye was but little irritated, and 
vision but slightly dimmed. On examination I detected a 
small fragment of steel in the iris close to its pupillary mar- 
gin, where it had lodged after passing through the cornea 
and across the anterior chamber. The corneal wound had 
healed so perfectly that to the unaided eye it was quite invisi- 
ble. I was assisted by Prof. Sim and Dr. Neely of this city. 
The eye was cocainized, after which I made an incision 
in the cornea similar to that employed in the preceding case, 
passed the electro-magnet into the anterior chamber and 8 
ELECTRO-MAGNETISM IN OPHTHALMIC SURGERY. 
onward toward the foreign body. When within half a mil- 
limetre of the latter it was seen to leave its bed in the iris 
and leap to the magnet, to which it adhered firmly, and was 
extracted without difficulty. To prevent if possible the dila- 
tation of the pupil by the cocaine, or on the escape of the 
aqueous humor, I had instilled eserin before the operation. 
It acted well, and on completion of the operation the eye 
presented a perfectly normal appearance, aside from the 
temporarily diminished depth of the anterior chamber, and 
slight conjunctival congestion. The value of the electro- 
magnet is here very strikingly shown, as before its employ- 
ment in ophthalmic surgery a foreign body situated where 
this one was could not have been removed without at the 
same time excising the segment of iris in which it was em- 
bedded. Indeed, on its firm entanglement in the iris would 
its removal and consequent rescue of the eye in a great 
measure depend. For if but slightly attached, manipulation 
with the forceps would almost certainly cause its displace- 
ment and disappearance into the depths of the eye from which 
the removal of so small an object could not be effected. 
Without the magnet the best that could be hoped for would 
be recovery, with a distorted pupil and more or less impaired 
sight. In this case, on the other hand, when discharged six 
days after the operation, the pupil was round and active, 
sight was perfect, in short the eye was in all respects abso- 
lutely normal. 
Other similar cases might be added from my clinical rec- 
ords, but the foregoing will suffice for the purposes of this 
paper. 
Masonic Temple, corner Madison and Second streets. 
Memphis, Tenn.