foreign body has been dislodged. Assistance from the same drug may be needed to enable us to see an abrasion produced by a twig, or very often by a baby’s fingernail. Usually the pain, photophobia, and lacrimation are quite pronounced in these cases, and frequently we can see the abrasion by the light reflected from its edges without the use of a stain, but there is no infiltration unless the place has become infected. In case of infection an ulcer appears which may become purulent if the nutrition of the patient is poor; this is the danger to be feared in a nursing mother, or it may prove the start of a serpiginous ulcer in an elderly person. Ordinarily the lesion heals within a few days, but treatment should be prolonged until the healing is firm, for the reformed epithelium is apt to be attached so loosely to Bowman’s membrane as to be detached again by insignificant causes and produce a recurrence of the same condition, or a bullous keratitis, weeks, months, or years afterward, although no new injury is known to have occurred. This is called a recurrent erosion.
<Callout type="warning" title="Warning: Infection Risk">Infections can lead to severe complications such as serpiginous ulcers and purulent infections.</Callout>
BURNS OF THE CORNA BURNS are recognized easily from the great irritation of the eye, the dull, cloudy, perhaps excoriated condition of part or all of the cornea, and the history of an accident in which some alkali, acid, or hot substance struck the surface of the eye. The con- junctiva is red and chemotic, and particles of metal, lime, or other corrosive substance may be found in the sac. Lime burns are the most common. The results depend on the depth to which the tissue is invaded, and the situation of the lesion on the cornea. A deep burn causes an ulcer which may or may not become infected, but heals like all others with the formation of cicatricial tissue. Super- ficial burns that affect only the epithelium cause sharp pain and photophobia, with a conjunctival redness of the eye, which pass away when the epithelium is restored. The history of exposure to a flash of blinding light, or of prolonged exposure to very strong light, or of the entrance of an acrid liquid or vapor into the eyes, enables us to make the diagnosis.
<Callout type="important" title="Important: Immediate Care">Immediate care for burns includes flushing with water and seeking medical attention.</Callout>
ULCERS OF THE CORNEA An ulcer of the cornea is a loss of substance that extends from the surface more or less deeply into the parenchyma, and is caused by a necrosis of the affected portion of tissue. It always starts as a grayish spot with its surface flush with that of the cornea, over which the epithelium may be unbroken, though usually it is steamy and lusterless, in an eye that presents a ciliary injection. This spot is a collection of cells which is called an infiltrate. The same name is applied to similar collections of cells that produce a cloudy appearance about the margin, or in the base of an ulcer while it is active; the absence of such infiltrates as these later on shows that the ulcer is healing, or has become indolent.
<Callout type="risk" title="Risk: Complications">Complications like perforation and ectasia can occur if ulcers are not properly treated.</Callout>
Several varieties of ulcers of the cornea are met with which differ not only in their clinical appearances, but also in their nature and course. Some are peculiar to certain diseases, others are common to many. They may be single or multiple, may attack the surface only, or penetrate deeply into the parenchyma, and may be round, oval, crescentic, or arborescent in form. Vascularity may or may not be a prominent feature. Usually they form grayish or yellow- ish opacities, some with, others without a purulent infiltration of the margins, walls, or bases. Some of the accompanying symptoms, such as ciliary injection, pain in the eye and brow, iritis, and hy- popyon, are proportionate to the seriousness of the condition, while others, like photophobia, lacrimation, and blepharospasm, may be disproportionately severe in mild cases and practically absent in bad ones, so that they cannot be relied upon for information as to the severity of the trouble. A simple ulcer is small, superficial, grayish, with only a slight ciliary injection. Sometimes its margins are slightly infiltrated, and it may show a little tendency to enlarge, when the ciliary in- jection becomes more pronounced. Occasionally it is somewhat vascular. Photophobia, lacrimation and blepharospasm are apt to be out of proportion to the pain, while iritis and hypopyon are ab- sent. It may be caused by traumatism, and is met with in many diseases, in which it may be multiple, and it frequently forms the starting point from which other varieties develop. In the absence of such a change, and in a well nourished patient, healing takes place quickly, as a rule.
In a badly nourished patient a simple may change into a deep, purulent ulcer, which presents a small, round excavation with yel- lowish walls surrounded by a zone of hazy cornea. The patients complain of pain in the eye and brow, though photophobia is less constant than in the simple variety, the ciliary injection is greater, the conjunctival vessels are congested, and sometimes an iritis with a small hypopyon is excited. This ulcer tends to perforate the cornea, but not to spread laterally.
A purulent ulcer that tends to progress rapidly over the surface of the cornea probably belongs to the extremely virulent serpiginous variety; it is met with only in elderly people. A simple round ulcer that starts near the margin of the cornea and moves toward the center, leaving a groove in which lies a leash of blood vessels, is called migratory. Such a condition, which is also called fascicular keratitis, is met with almost exclusively in phlyctenular keratitis. One or more crescentic ulcers sometimes form near the margin of the cornea in severe cases of catarrhal or purulent conjunctivitis, and extend rapidly, following the course of the limbus. The con- junctiva usually is chemotic, and is apt to overhang the corneal limbus so as to conceal the ulcer, which consequently may be over- looked until it is too late to save the eye, unless the overhanging conjunctiva be pushed aside so as to expose the margin as a part of the routine examination when such a chemosis is present. This complication of acute catarrhal conjunctivitis is most apt to occur in patients who are old or debilitated, and it is the less common form of ulceration met with in gonorrheal conjunctivitis of both adults and infants.
Sometimes a crescentic ulcer is formed in phlyctenular keratitis by the coalescence of a number of marginal lesions. Unless arrested a crescentic ulcer threatens to cut off the nutrition from the central part of the cornea, which will then break down into pus. A central infiltrate or ulcer having ill defined edges, with a ciliary injection, but with no pain, photophobia, or lacrimation, suggests a neuroparalytic keratitis. An infiltrate or ulcer in the lower part of the cornea, limited above by a horizontal line, with the adjoining conjunctiva on each side swollen and covered by crusts that may lie partly on the cornea, is a symptom of keratitis e lagophthalmo. A horizontally oval ulcer near the center of the cornea, and on 166 DIAGNOSIS FROM OCULAR SYMPTOMS the line of demarcation of a pannus which covers the upper part, is trachomatous. A chronic ulcer with undermined edges that cicatrizes, recurs with an extension of its margin into the clear tissue, and slowly extends in this way over the surface of the cornea, probably is the rare variety commonly known as Mooren’s. A superficial, narrow, zigzag opacity with ciliary injection, photo- phobia, blepharospasm, and lacrimation, probably indicates a den- dritic keratitis. A round depression in the surface of the cornea with walls and base which are slightly hazy or perfectly transparent, associated with no ciliary injection or any other sign of irritation of the eye, is an indolent ulcer. It may remain superficial and apparently unchanged for a long time, it may fill up gradually, or it may deepen slowly and even perforate the cornea, if it is left alone. Such ulcers occur sometimes .in chronic catarrhal conjunctivitis and in trachoma.
A congenital deep opacity associated with enlargement and ectasia of the cornea, is thought by some to indicate the presence of an ex- cavation or ulcer on the posterior surface. Nebula, Macula, Leucoma All ulcers and wounds leave cicatrices when they heal that corre- spond in location, size, and shape to the lesions which produced them, and generally they are proportionate in their density to the depth to which the tissue was invaded. A very superficial ulcer may leave a scar that is so faint as to be scarcely perceptible; this is called a nebula. Another that penetrates somewhat more deeply leaves a distinctly visible, though fairly transparent opacity termed a macula. One that penetrates still more deeply leaves an abso- lutely opaque white spot known as a leucoma. Nebule and macule acquired in early life tend to clear up as the patient grows older, so that after some years they may become hard to detect, and im- pair the vision mainly through the irregular astigmatism they occa- sion, but this tendency to clear up is much less marked in later life. All signs of irritation leave the eye with their formation, so when we see a spot on the cornea with no vascularity and no ciliary in- jection we think at once of a cicatrix. Sometimes the cicatrization stops before the loss of substance has been quite replaced and leaves THE CORNEA 167 a concave spot called a facet. The only conditions we have to ex- clude when we see such a spot are congenital opacities, the arcus senilis and spots of degeneration. Arcus Senilis We see very often an opaque arc or circle separated from the margin by a narrow band of clear cornea. Unless the patient gives a history of a violent inflammation of the eye in years gone by, this marks a hyaline degeneration which appears to be physiological and not to indicate any impairment of nutrition. It never extends toward the ecenter, and does not interfere with the healing of a wound. Usually it occurs in elderly persons, whence it derives its name, but sometimes it is seen in young ones. Rarely it may, be changed into a grooved depression. The presence of a clear zone between it and the margin serves to exclude an opacity left by a deep marginal keratitis in the great majority of cases, though it may not always be possible to differentiate it positively from a scar left by a rather slight crescentic ulcer, when it is known that the eye has been severely inflamed in the long distant past.
Degenerative Changes in the Cornea A band of opacity that develops quietly, with no sign of irritation of the eye, that extends horizontally across the cornea, and has a peculiar granular appearance that contrasts with the smooth sur- face of a cicatrix, probably is the result of a calcareous degeneration in which lime salts have been deposited beneath the epithelium. This is the ribbon shaped degeneration, which occurs generally in eyes which have been blinded by iridocyclitis or glaucoma, but a few cases of this nature have been met with in eyes that apparently were otherwise healthy. Removal of the salts has produced good results in these last cases. We may find the vision impaired by the presence of a group of little grayish, subepithelial nodules in the center of the cornea, which change very slowly, are covered by intact and lustrous epithelium, and are accompanied by slight if any signs of irritation of the eye. This is Groenouw’s nodular degeneration of the cornea. The nodules are situated in and about Bowman’s membrane, do not seem to penetrate deeply, and may contain hyalin. Between them a fine grayish stippling of the cornea may be seen. The diagnosis is made 168 DIAGNOSIS FROM OCULAR SYMPTOMS from the appearance, the absence of signs of irritation, and the chronic character. It may be made positive by the microscopical examination of an ablated piece of the tissue. Very recently Uhthof' has described what seems to be a variety of the above in which he found little gray, conical formations ex- tending from the subepithelial part of the cornea down deep into the posterior layers, that did not tend to group themselves in the center or in any other one part, and had no stippling of the cornea between them. We know very little about either of these forms of degen- eration.
More commonly when we speak of degeneration of the cornea we refer to a hyaline, an amyloid, or a calcareous degeneration of a corneal cicatrix. Occasionally we see what looks like a drop of yel- low, or yellowish gray substance in a white leucoma, and then we have reason to believe that the scar is undergoing hyaline or amyloid degeneration; which of these it is we cannot tell without excising a piece and testing its chemical reaction. In other cases we see chalky white granules in a leucoma and understand that earthy salts are being deposited. When the extent of such a degeneration as either of these is considerable the epithelium covering it is apt to give way and so create a superficial, but obstinate ulcer over the site of the leucoma.
Keratocele When an ulcer has eaten away the tissue of the cornea down to Descemet’s membrane, we occasionally are able to see a transparent, rounded bleb in the excavation, surrounded by a gray ring. This protrusion is caused by the driving forward of that membrane by the intraocular pressure so as to make it bulge into the opening, and probably occurs in every case in which an ulcer perforates the cornea, but in most cases it is so evanescent that it is not observed. When a keratocele is seen it may be regarded as evidence that Des- cemet’s membrane is unusually resistant, or that the intraocular pressure is low, and we must not despair of being able to prevent its rupture.
Perforation of an Ulcer and its Consequences The patient feels a sudden pain in his eye, accompanied by a gush of fluid, when the keratocele bursts, and if we see the case at once we find the iris and lens in apposition with the posterior surface of ° THE CORNEA 169 the cornea. The perforation may close with the formation of a sim- ple leucoma, but this is not common. Still less so is the production of a scar composed of corneal and cicatricial tissue alone, which is so weak as to bulge before the intraocular pressure and form an ectasia. The iris is brought into contact with the internal opening and occludes it in most cases. If the opening is small it may remain attached at this point of the posterior surface, and healing take place with the formation of an anterior synechia. A larger open- ing permits the iris to enter, perhaps to prolapse, and then it re- mains entangled in the cicatrization with the production of an adherent leucoma. When a still larger place in the cornea has been destroyed more of the iris prolapses and unites with the remains of the corneal tissue to form a broad cicatrix, which, if sufficiently firm and strong, flattens and may reduce the size of the cornea by its contraction. If the cicatrix is too weak to do this, or to withstand the intraocular pressure, it bulges forward and gives rise to a staphy- loma, the size of which depends on that of the preceding ulcer.
In other cases the capsule of the lens may block the opening, when healing probably will take place with the formation of a sim- ple leucoma of the cornea and an anterior capsular cataract of the lens. When a central perforation occurs in ophthalmia neonatorum while the child is crying or straining, the lens may be extruded through the opening.
A different result seen sometimes after the perforation of an ulcer, as well as after a wound, whether operative or not, is a failure to heal, leaving a fistula. The anterior chamber does not refill, the iris and Jens remain in apposition with the cornea, or the anterior chamber may refill to a certain degree and a little bleb or keratocele appear and rupture from time to time. This condition is one which is very menacing to the integrity of the eye.
Intraocular hemorrhage sometimes, though rarely, happens when the tension is reduced suddenly by the escape of aqueous in cases of absolute glaucoma, and in patients whose retinal or choroidal vessels are sclerotic. Finally the perforation of an ulcer opens a channel through which vus agents may enter the eye and cause panophthalmitis.
Ectasia of the Cornea This is a small protrusion of the corneal tissue alone, without involvement of the iris, which occurs very rarely. A congenital 170 DIAGNOSIS FROM OCULAR SYMPTOMS malformation of this nature has been met with, in which a portion of the perfectly clear cornea projected forward with a different curvature and refraction from that of the rest. The acquired con- dition appears when the cornea, or a portion of it, has been so weakened by disease that it yields before the intraocular pressure, and has been met with after interstitial keratitis, trachoma and ulcers.
Staphyloma of the Cornea When a portion, or the whole of the cornea has been replaced by an opaque, protuberant mass, the question is whether we have to deal with a tumor or a staphyloma. The differentiation is easy in most cases, though sometimes it is not, and then we have to rely on the history, which is characteristic in each case. When we are told of a violent inflammation that left the eye practically blind through the production of a corneal scar that gradually grew more and more prominent, the case is one of staphyloma, while if a small growth appeared and
Key Takeaways
- Corneal ulcers can be caused by infections or burns.
- Treatment should continue until the ulcer is fully healed to prevent recurrence.
- Recognize signs of severe complications like perforation and ectasia.
Practical Tips
- Always seek medical attention for corneal injuries, even if symptoms seem minor at first.
- Use sterile saline or clean water to flush out foreign objects from the eye before seeking help.
- Avoid touching or rubbing the affected area to prevent further damage.
Warnings & Risks
- Infections can lead to severe complications such as serpiginous ulcers and purulent infections.
- Improper treatment of corneal ulcers can result in permanent vision loss.
- Ignoring symptoms can delay necessary medical care, worsening the condition.
Modern Application
While many of the techniques described here are outdated, understanding the signs and symptoms of corneal injuries remains crucial for modern survival preparedness. Immediate care such as flushing with water and seeking professional help quickly can prevent complications that could lead to permanent vision loss or even blindness.
Frequently Asked Questions
Q: What is a recurrent erosion in the context of corneal ulcers?
A recurrent erosion occurs when an ulcer heals but the reformed epithelium becomes loosely attached to Bowman’s membrane, making it susceptible to detachment and recurrence. This can happen weeks, months, or years after the initial injury without any new trauma.
Q: How should a burn on the cornea be treated?
Immediate care for burns includes flushing the eye with water to remove any irritants and seeking medical attention as soon as possible. Proper treatment can prevent complications like ulceration or perforation of the cornea.
Q: What are some signs that a corneal ulcer may be severe?
Severe corneal ulcers often present with symptoms such as intense pain, photophobia (sensitivity to light), and significant redness. The presence of an ulcer with purulent infiltration or perforation is particularly concerning.