warm and sunny weather. At such a period, the eye is often excited
by reflection of intense light from the surface of the earth; and is
irritated by sudden exposure to a degree of light to which it has not
been previously accustomed. Different directions of the sun’s rays,
and different kinds of light, seem to exert different influences
on the organ. The rays are most hurtful when they do not fall in a
perpendicular direction on the eye, but slopingly or horizontally.
Strong light from the moon, and light reflected from scarlet, are also
particularly injurious. Undue exertion of the eye weakens it, and
renders it prone to become inflamed. The eyes of infants are often
violently inflamed, in consequence of imprudent exposure to light
before they have been gradually accustomed to its stimulus. Again,
inflammation is caused by imprudent exposure of the eye directly to
cold, or by exposure of other parts causing suppression of their
discharges, whether natural or not. Inflammation of the conjunctiva
often follows suppression, however occasioned, of the menstrual or
hemorrhoidal discharges, as also suppression of discharges from
the urethra, from the Schneiderian membrane, or from behind the
ears. Irritations in the neighbouring parts, as in the mouth during
dentition, may also excite the disease. Immediate irritations, however,
are the most frequent cause, as the lodgement of extraneous bodies on
the surface of the organ—particles of sand, dust, snuff, pepper, or
gunpowder, minute insects, loose or inverted eyelashes. By the presence
of such substances, the eye is often kept in a very irritated state for
a long period. The most violent conjunctival inflammation is sometimes
produced by contact of gonorrhœal matter through carelessness.
Occasionally metastasis of inflammation takes place from one eye to
another; so that a person may be seen one day with severe inflammation
of the right, and on the following day with a similar affection of
the left, and the right entirely free from disease. Another cause,
sometimes met with, of inflammatory action in the conjunctiva, is
the lodgement of large foreign bodies in the orbit, with or without
destruction of the eye; as splinters of wood, straws, rusty iron nails,
sharp portions of stone, &c., penetrating the globe of the eye, or
parts in the immediate neighbourhood. Upon removal of the cause, the
redness, discharge of tears, pain, &c., sometimes subside without
inflammation having been established, the vessels of the part regaining
their contractility; but if the cause is continued for any considerable
time the effects do not rapidly abate. Wounds and other injuries of the
organ are generally followed by inflammation. But a simple clean wound
or puncture made with a fine instrument, as in many operations, and in
a favourable constitution, frequently produces little or no excitement
of the part. The degree of excitement must of course depend upon the
nature of the wound, the structure of the parts involved, the lodgement
or not of the body by which the wound is inflicted, and many accidental
circumstances. The eye may be injured by acids or by lime, and the
textures acted upon chemically; again, the membrane may be wounded by
pieces of hot metal, and then the destructive action is both chemical
and mechanical: in both cases active inflammation of the injured
conjunctiva is kindled. The state of the patient’s constitution
modifies very much inflammatory action of the eye, however induced;
and it has been observed, that dark eyes bear injury or incited action
better than those of a light hue. Not unfrequently conjunctivitis is
a secondary affection, accompanying eruptile diseases, as measles or
small-pox.
In considering the disease, it is necessary to keep in mind the loose
connection of the membrane with the subjacent parts, as well as its own
texture and functions.
In conjunctival inflammation, the patient first feels a degree of pain
and stiffness in moving the organ; and has always a feeling as if a
foreign body were present, whether such is the case or not. There is
also a degree of itching with a sensation of fulness in the part, and
this is followed by redness of the membrane, becoming more and more
intense. If the disease gain ground, the colour changes to a darkish
red or purple hue. To the redness succeeds heat, with profuse and
hot lachrymation. Then swelling supervenes, often to a great extent:
the vessels, both veins and arteries, are much gorged, and effusion
of serum or blood takes place into the loose cellular tissue which
connects the conjunctiva to the sclerotic.
In some cases, the effusion in this situation is very considerable;
lymph as well as blood is deposited, and a bulging forwards of the
conjunctiva is produced; the stretched membrane becomes thickened, of
a raw granulated appearance, and a bright scarlet hue, and the cornea
appears sunk in the midst of the swelling, and almost hid by it: this
state of matters is termed _Inflammatory Chemosis_, and only occurs
when the excitement is very intense.
Blood is frequently effused beneath the conjunctiva in small quantity,
in consequence of a bruise or other injury of the eye,—from violent
exertion, as during coughing,—or from a less degree of inflammatory
action than in the preceding case; but the swelling thereby occasioned
is comparatively trifling, and the effusion is, in general, speedily
absorbed. To this affection the term _Ecchymosis_ is attached.
In inflammation of the external parts of the eye, the redness begins
from the margins of the organ, and gradually diffuses itself towards
the cornea. Such is not the case in inflammation more deeply seated.
There is intolerance of light in a slight degree, and the patient is
inclined to keep the eyelids shut. At first the discharge from the
conjunctiva and meibomian glands is increased and changed, and flows
occasionally over the cheek, producing a scalding sensation. When the
eyelids are at rest, as during the night, they become glued together by
the viscid fluid from the meibomian follicles; but, if the inflammation
increases in intensity, the discharge is arrested.
In external inflammation there is more or less constitutional
disturbance, proportioned to the violence of the action and the
irritability of the system. In most instances the patient complains of
headache.
The above symptoms subside along with the inflammation; but, if this
has been at all severe or protracted, distension of the vessels to a
considerable degree continues, and the ophthalmia becomes chronic. This
change from acute to chronic takes place at various periods of the
affection, according to the intensity of the action, the nature of the
cause, and the irritability of the constitution. And again, the second
stage of ophthalmia may revert to the first, acute inflammation being
rekindled by fresh irritation of the organ.
_Purulent Ophthalmia_ most frequently occurs in warm climates, and
is attended from the first with profuse puriform discharge from the
conjunctiva. In the natural state of the organ, the conjunctival
discharge is pellucid, and so small in quantity as to be indiscernible;
but in this disease it possesses all the external characters of pus,
and is secreted in large quantity. The affection commences generally
in the under eyelid, with a feeling as if sand or foreign bodies were
lodged in the eye. The parts swell very much, and the eyelids become
more or less inverted, in consequence of serous effusion into their
cellular texture. Frequently the patient experiences an exacerbation
of the complaint about three or four hours after each meal. Though the
disease usually commences in the conjunctival lining of the eyelids,
the external coverings of the ball are often secondarily affected. In
some cases the bulb becomes the seat of lancinating pains; its coats
give way; the humours are discharged; and the eye sinks, with immediate
relief to the patient from the more urgent symptoms, but at the same
time with irreparable loss of vision. In other instances the effects
are less injurious to the structure of the organ, but equally so to
the sense of vision: the cornea becomes dull, and ultimately opaque,
or ulcerates, or partially sloughs; the swollen conjunctival surface
of the lids is covered with granulations, and secretes a copious
puriform discharge, with or without eversion, according to the degree
of swelling. At first the lids are more or less inverted, on account of
œdematous swelling of the cellular tissue: in the latter stages they
are everted by thickening and turgescence of the conjunctiva. This
membrane is at first villous and of a dull red colour, relaxed, and
its vessels enlarged and loaded; afterwards it becomes hard, almost
warty, and continues to discharge puriform fluid. The latter state
of the lining of the lid produces disease of the cornea, opacity of
a greenish colour, or an ulcer with intolerance of light, and other
symptoms of disorganisation proceeding in that tissue. The disease is
supposed to be contagious, and was the scourge of the British army for
many years after the campaign in Egypt. In that country it seems to be
caused by exposure to cold and damp during the night, and the intense
rays of light during the day, more especially when these causes act
on eyes which have not been accustomed to such vicissitudes. After
its invasion, it is communicable to others by contact of the morbid
secretion; and in individuals who have been once affected the disease
is very apt to recur when they are crowded together in unhealthy
situations.
A disease of equal malignity, and resembling in all respects the
Egyptian ophthalmia, occurs from the application of gonorrhœal matter
to the conjunctiva, or on sudden suppression of the gonorrhœal
discharge,—metastasis of the action sometimes takes place from the
urethral membrane to the conjunctiva. The eye is seldom saved from
the destructive effects of the violent inflammation which follows the
contact of the morbid fluid. Of all forms of purulent ophthalmia, the
gonorrhœal is the most rapid in its course and destructive in its
effects.
[Illustration]
Children are not unfrequently the victims of purulent ophthalmia—the
_ophthalmia neonatorum_. Immediately after birth the conjunctival
lining of the eyelids seems unusually red and turgid, and a great
degree of swelling soon takes place, so as to render separation of
the eyelids very difficult. Occasionally eversion of the lids occurs,
when the child cries, from sudden and forcible contraction of the
strong external fibres of the orbicular muscle. In general, the lids
soon relapse into their former situation; but sometimes the eversion
remains, if the internally projecting tumour of the conjunctiva is
allowed to become still more swelled from strangulation, caused by
the outer margin of the reflected lid. The inflammation spreads over
the ball; and, in general, the swelling of the conjunctiva, being
greatest at the circumference of the eye, bulges out the eyelids, and
turns in their margins. Puriform matter is secreted copiously, and is
confined, more especially when, from inattention, the margins of the
lids are allowed to become glued together. They often adhere so firmly
as to require a very considerable force for their separation, and when
opened the matter gushes out as if from the cavity of an abscess. From
confinement of the matter the inflammation is still more increased,
and the cornea involved. Whitish specks form on it, or it ulcerates,
and the ulcers make their way into the anterior chamber of the eye; or
portions of it slough, causing partial loss of the organ and openings
into the chamber, in consequence of which the aqueous humour is
discharged, and the cornea sinks and becomes flaccid. In many instances
the cornea becomes opaque, changed in texture, and increased in
thickness, so as to form a convex projection from betwixt the eyelids,
termed _Staphyloma_; the sclerotic coat also is occasionally affected
in a similar manner. A frequent cause of purulent ophthalmia in
children is imprudent exposure of the eyes to strong light, the parent
or nurse not remembering that the organ must be gradually accustomed to
the stimulus. Exposure to cold may also induce the inflammatory action.
The application of leucorrhœal or gonorrhœal matter to the eyes of the
child, whilst passing through the vagina of the mother, is perhaps
the most common cause of the disease. A very unhealthy state of the
constitution accompanies the affection: the scalp and other parts of
the surface are frequently covered with eruptions. A singular result
sometimes follows the purulent ophthalmia of infants. A small opaque
spot is observed on the capsule of the lens, which remains through life
a central spurious capsular cataract.
_Inflammation of the Cornea_ supervenes on simple conjunctival
inflammation, and frequently on the purulent. The vessels of the part,
both veins and arteries, previously carrying single and therefore
invisible blood corpuscules, become much dilated, are filled with
numerous globules, and hence are rendered red and conspicuous to the
unassisted eye. Writers on ophthalmic surgery, in their rage for
refinement, speak of three kinds of this inflammation—inflammation
of the external or conjunctival covering, of the middle tunics or
cornea propria, and, lastly, of the third coat, the capsule of the
aqueous humour: such distinctions, however, are found to effect no good
practical end, and it is unnecessary to follow them. One particular
layer of the cornea may be first attacked, but the whole structure
soon becomes involved. The inflammation generally commences in the
conjunctival covering. Vision is necessarily much obscured from even
slight inflammatory affection of the cornea. Part only of the organ may
be affected, but frequently the whole is involved. Sometimes only one
or two vessels remain dilated; but still they, passing over the centre
of the cornea, render vision indistinct. Opacity of the cornea, to a
greater or less degree, always attends dilatation of its vessels.
In inflammation of the internal and middle tunics of the cornea,
most of the enlarged vessels which traverse it are seen to be
continuations of those that ramify in the conjunctival covering; while
the anastomotic vessels derived from the sclerotic coat are smaller
and less apparent than those of the conjunctiva. The cornea, and the
sclerotic immediately surrounding it, frequently appear to be almost
entirely covered with meshes of their dilated capillaries. At first
the whole cornea has a clouded appearance, but as the disease advances
portions become distinctly opaque, and at these points either lymph
or pus is effused. Sometimes matter collects between the laminæ,
distends them, and, causing ulceration, discharges itself either into
the anterior chamber or externally. Inflammation of the cornea arises
frequently from lodgement of a foreign body in it: and ulcers of it
are often produced by a similar cause. If the extraneous matter is not
removed soon after its insertion, nature commences her endeavours to
detach it, and the process employed is ulceration. Sometimes, however,
a sac is formed around the foreign body as in other parts, and no ulcer
is produced.
Ulceration of the cornea also takes place in order to afford an exit
to matter formed between its layers deeply or superficially. Deep
abscess of the cornea is by no means a rare consequence of violent
inflammatory action in the part. A minute opaque spot is at first
seen; this extends, assumes a yellow colour, and does not change its
situation on the head being moved. The internal lamellæ may ulcerate
in consequence of the pressure; but this seldom happens; the matter
is discharged externally. Suppuration in this situation is often
attended with much pain. Abscess of the surface of the cornea is of
more frequent occurrence than one more deeply seated: from its external
covering yielding readily to the pressure of the accumulating matter,
it generally assumes a pustular form. The fluid in such cases is
sometimes absorbed, and no vestige of disease remains in the part; but
more frequently the apex of the pustule gives way, and an ulcer is the
consequence. A similar result takes place if an artificial opening is
made for evacuation of the matter; and it may be considered as a good
rule in practice not to interfere with collections in the cornea, as
there is a probable chance of the matter being absorbed, and the cornea
regaining its transparency; while it is certain that breach of its
surface, in such cases, though made by the most delicate instrument,
will give rise to ulceration.
_Pustular Opthalmia_ is at some seasons frequently met with: small
pustules, sometimes numerous, form on the conjunctiva, whilst that
membrane is turgid and its vessels dilated; the sclerotic conjunctiva
around the cornea is their most common situation, but sometimes almost
the whole conjunctival surface appears studded with them. When the
cornea is affected, the pustules frequently give way, and produce
ulceration; and when the pustules are numerous, and surrounded by much
vascularity, the part becomes opaque as well as ulcerated.
In weak constitutions _Ulcers of the Cornea_ occur from slight
causes,—exposure to strong light, intemperance, inverted or irregular
ciliæ, a granulated state of the lining of the lids, or from momentary
irritation of the part by extraneous matter. The ulcer appears at first
circular, but during its progress it often becomes of an irregular
form; its surface is depressed and ragged, and can readily be seen by
directing the patient to fix the eye, and then looking at the part
from one side. The edges are elevated; and the surface, which is of
an ash colour, discharges an acrid colourless fluid, as in similar
affections of all surfaces that are covered with a delicate, tense,
and exquisitely sensible expansion. Sometimes the ulcer is very minute
and superficial, and enlarges very slowly, if at all; but in other
instances it extends rapidly in depth and size, with great pain and
irritability of the organ, and intolerance of light. Occasionally their
increase is expedited by partial sloughing. At first, when the ulcer
is minute, the part often retains its natural transparency. But as the
disease advances, when the sore spreads superficially either by the
sloughing or the ulcerative process, or by both, the cornea becomes
opaque, often to a considerable extent, around the ulcerated part;
and if the ulcer extends deeply, so as to perforate the tunics, the
aqueous humour escapes, the iris falls forward, and the pupil becomes
distorted: in either case vision is impaired or destroyed. In some
cases great relief follows discharge of the humour, and the consequent
flaccidity of the cornea, the ulcers seeming to have been prolonged
and irritated by the fulness of the chamber. Sometimes an ulcer will
penetrate the laminæ of the cornea, even to the aqueous membrane. This
latter tissue may resist the ulcerative process, and will then be
pushed forward into the opening by the pressure of the aqueous fluid.
This is _the hernia of the aqueous membrane_, so called, instances of
which have been known to acquire a considerable size before the bag has
given way.
_Abrasion_ of the conjunctival covering of the cornea is produced by
accident, or follows incited action of the vessels. The abraded surface
either ulcerates, or contracts and heals kindly, with or without
opacity of the part. Breach of surface in the cornea,—whether an ulcer,
an abrasion, or a raw surface, caused by the giving way of a pustule,
or of a small abscess,—is constantly liable to irritation, on account
of not being protected by mucous membrane and mucous discharge: even
the contact of the tears irritates, and keeps up inflammatory action in
the membranes. When the ulcerative process ceases, lymph is effused,
and a grayish halo forms around the sore; the ash colour of the surface
of the sore disappears, and is succeeded by florid granulations,
extremely minute, which fill up the cavity; cicatrisation follows
in due time, with subsidence of all the symptoms and appearances of
inflammation. There remains, however, an opaque speck of a pearly
hue corresponding to the sore, but occupying rather less space. When
the cornea is perforated by ulceration, the sore sometimes shows no
disposition to heal, becoming a fistulous aperture through which the
aqueous humour is from time to time discharged. By this condition of
parts vision is much impaired, the cornea being always more or less
flaccid. Touching the fistulous opening with the nitrate of silver,
reduced by scraping to a very fine point, will often promote a healthy
action in the tissue, and effect adhesion of its sides.
The pearly speck which remains after cicatrisation of a corneal sore
is termed _Leucoma_, and is permanent. It is generally of an uniform
colour, but occasionally a black speck is perceptible in some part of
it. For, when an ulcer lays open the anterior chamber, part or the
whole of the aqueous humour is evacuated, and the iris falls forward;
a portion of the iris falling into the opening, provided this is
not in the centre of the cornea, closes it up, and becomes adherent
to that part. If the opening is large, the prolapsus of the iris is
considerable; and in some cases this membrane, being pressed on by the
humours, is forced through the opening in the form of a small bag.
This change of position is termed _Hernia of the Iris_; and the dark
sacculated portion of the iris which projects from the surface of
the cornea is called _Myocephalon_, from its resemblance to the head
of a fly. The myocephalon may remain for a considerable time, or may
sphacelate and drop away. The pupil is thus rendered irregular, is
perhaps nearly obliterated, or is drawn down behind the opaque part,
and thereby rendered totally useless to the patient. The impairment
of vision caused by Leucoma depends on the size and situation of the
speck. The disease is irremediable, though the thin cloudy opacity,
which frequently surrounds the leucoma, may be dissipated. The
operation of artificial pupil is sometimes required, in order to afford
a degree of vision in this affection of the cornea,—as well as in the
speck of a similar appearance occasioned by effusion and organisation
of lymph betwixt the deep lamellæ of the cornea, and which is termed
_Albugo_.
[Illustration]
Albugo occurs during the intensity of inflammatory attacks. It also
is surrounded occasionally by thinner opacity, but not depressed and
unequal on the surface, as leucoma sometimes is. Large and tortuous
vessels are generally seen passing into albugines, but meshes of dilated
vessels are seldom present. When the affection is recent, it sometimes
disappears under proper treatment, especially in young subjects; but
the albugo is by no means so readily removed as the _Nebula_, or thin
cloudy opacity which is the frequent consequence of obstinate chronic
dilatation of the conjunctival vessels. Nebula is superficial, and
consists of mere thickening of the conjunctival covering, from lymph
having been effused. It impairs vision, but does not destroy it, for
the affected part remains semitransparent.
In strumous constitutions specks of the cornea are often accompanied
with ulceration of the edges of the palpebræ, and destruction of the
ciliæ—_the ophthalmia tarsi_. The margins of the eyelids are red and
slightly tumid, and discharge an acrid fluid; the ciliæ are matted
together; pustules form at their roots; the bags which secrete them
are laid open and destroyed, and they consequently fall out. The
affection is often of long duration, and may be in part prolonged by
vitiated secretion from the meibomian glands. During its progress it
excites very considerable irritation in the whole eye, and, as has been
already stated, opacities of the cornea not unfrequently accompany it.
Veins become enlarged, and varicose on the conjunctiva, as also their
minute ramifications on the clear part of the ball; small reddish lines
appear on the cornea, and around them is “diffused a thin, milky, or
albuminous humour,” which destroys its transparency at that part.
Such spots may be solitary or numerous, and darken the cornea either
partially or entirely. They are always surrounded with a fasciculus of
enlarged veins.
In elderly people a dim opaque ring, of a greyish colour, sometimes
encircles the margins of the cornea, and is called _Arcus Senilis_; but
this can scarcely be looked upon as a disease.
Sometimes the cornea presents a _spotted_ appearance; and this state of
the organ is generally attended by obstinate inflammatory action in the
part. The affection, however, is rare. I have seen several instances of
it: in one, both corneæ were spotted, and sight was almost destroyed,
without much irritability of the organ. The disease yielded to external
stimulants, and the internal use of the bichloride of mercury. It is
met with in a chronic and very intractable form.
The cornea may sometimes be rendered dim by _over-distension_, the
aqueous humour being unusually copious.
Occasionally _sloughing_ takes place in the cornea from over-action. It
is dangerous to the structure and functions of the organ, according to
the extent to which it occurs.
_Ossification_ of the cornea is said to take place; but few cases are
on record, and these were in very old people.