Corneal opacity is a disease of the cornea, which is comparatively common. Nevertheless, it is relatively unknown, which is due to its many causes. It is also difficult to treat.
What is corneal opacity?
A corneal opacity is a reduced transparency of the cornea. The condition most often results from pathologic or degenerative changes in the cornea and is often associated with a noticeable discoloration of the outermost layer.
Causes
Corneal opacification can be caused by a number of things. Most commonly, it results from scarring or swelling on the cornea caused by ulcers or injuries. When the cornea swells, fluid enters it and slowly clouds over. This reduces vision and permanently changes the color of the cornea. In addition, hereditary metabolic disorders such as stromal corneal dystrophy can cause corneal opacification. Injuries to the eye and specifically to the cornea are generally a common cause of opacification. In particular, if thickening occurs that is not treated, the effect can be permanent. Lastly, corneal opacification can also be caused by infection with herpes viruses. These enter the eye through foreign bodies such as contact lenses. Eye diseases such as keratoconus also cause corneal opacity.
Symptoms, complaints, and signs
Corneal opacification is initially manifested by a decrease in visual acuity. Affected individuals first notice a decrease in vision, which may include a clouding of the field of vision and excessive sensitivity to light. Those affected usually also notice a kind of foreign body sensation in the eye, which increases in the course of the disease and is perceived as very unpleasant. Small blisters may form in the area of the cornea, which hurt when touched. When the vesicles open, severe pain occurs and there is a risk of acute ocular inflammation. As the disease progresses, corneal ulcers may form. If corneal opacification is not adequately treated, visual symptoms increase and eventually complete blindness occurs. Previously, images are increasingly perceived blurred and distorted, often the opacity leads to falls or accidents in everyday life. Externally, corneal opacification is manifested by white discolorations that form a film on the cornea and severely cloud the affected eye. The discoloration intensifies as the disease progresses and eventually affects the entire eye. Sometimes redness of the eye margins is added or visible keratinization forms in the eyelid area.
Diagnosis and course
Schematic diagram showing the anatomy of the eye with myopia and after treatment. Click to enlarge. Corneal opacity can usually be diagnosed by the affected individual. This is done based on the various symptoms, such as a decrease in visual acuity and excessive sensitivity to light. In addition, small blisters may appear on the surface of the cornea. This is the case, for example, with untreated injuries. If one or more of the above symptoms are present, a visit to the ophthalmologist is recommended. The ophthalmologist can narrow down the possible diseases in a discussion with the patient and make a diagnosis on the basis of various examinations. An eye test as well as a detailed examination of the cornea with the help of a so-called slit lamp are important parts of the examination. The exact diagnosis can be made if white-greyish discolorations are found in the area of the cornea during these examinations. Thickening is also a clear sign. The course of corneal opacification is similar in most cases. Initially, the affected person perceives only minor opacities and sees images distorted and blurred. If the clouding is then not treated, the affected person perceives less and less and eventually goes completely blind. This process can take years. It may also be that the clouding stops progressing after a certain point, but the limitations in daily life are still significant.
Complications
Corneal opacification that has not progressed very far can often be treated conservatively. This treatment involves fitting a hard contact lens to correct any refractive error present.However, if the actual condition does not stabilize with this lens, corneal transplantation may become necessary. Corneal inflammation, which must be treated antibiotically and anti-inflammatory with appropriate medication, cannot be ruled out concomitantly or subsequently. There is a risk of damage to structures in or on the eye. Also inflammations as well as healing disorders or scarring cannot be excluded. Bleeding and inflammation of the retina can occur, but fortunately are considered very rare. There is also the risk of a new corneal opacification. This would result in a new operation. In rare cases, retinal damage or allergic reactions may occur. A sometimes occurring defective vision or a change in the refractive power can usually be compensated well with glasses or contact lenses, so that the complication usually does not lead to serious limitations. Extremely rarely, blindness or loss of the operated eye occurs.
When should you see a doctor?
One should see an ophthalmologist whenever symptoms such as severe sensitivity to light appear, possibly still in combination with deterioration of vision and pain in the eye. If a corneal opacity is detected early enough, the chances of treatment are good. Therefore, it is also important to go to the doctor at the first symptoms. At-risk groups include contact lens wearers, people who have had corneal injuries or ulcers in the past, and people with a history of herpes infection. These sufferers should have their symptoms investigated at the first sign of corneal opacification. It is useful to record them in a diary. These records are helpful for the physician. If the corneal opacity is based on a hereditary predisposition, doctors try to carry out a preventive treatment. It is imperative that corneal opacity be treated by a doctor, otherwise irreparable damage to the eye may occur, and in the worst case, blindness may be imminent.
Treatment and therapy
Corneal opacity cannot be corrected by conventional therapeutic methods. The only way to effectively treat the opacity is to transplant a donor cornea. These are obtained through special cornea banks, for which long waiting lists exist. However, they can also be used immediately in an emergency situation such as an accident or worsening of the corneal condition. Smaller scars or opacities can be repaired with the help of modern treatment methods at least to such an extent that there are no more difficulties for the affected person in everyday life. As a rule, a laser is used for this purpose. In this form of treatment, known as phototherapeutic keratectomy (PTK), the hardened tissue leading to the opacity is carefully removed, thereby also correcting the opacity. Because the procedure is risky, it is only considered if it is truly necessary. If surgical intervention is necessary, depending on the situation, general or local anesthesia is used. The surgeon removes the diseased cornea with the help of a surgical microscope and then sutures the donor cornea onto the eye. After the operation, the patient must also use antibiotics, ointments and other preparations to prevent inflammation. Finally, after one year, the stitches are removed and the patient has full vision again.
Outlook and prognosis
If corneal opacification is caused by swelling in the eye after a fall or accident, the patient usually makes a full recovery once the swelling has healed. The prerequisite for this is that no permanent damage or irreparable damage has occurred. In the case of a scar in the cornea or a metabolic disease of the patient, an individual analysis of the patient’s state of health must decide which steps can be taken to improve the patient’s health. Smaller scars can be treated with the modern therapeutic methods. Often a significant alleviation of symptoms or freedom from symptoms is possible. In the case of larger scars or damage, the prognosis is unfavorable. Without surgical intervention, there is no improvement in vision. A transplantation is necessary in order to have a chance of alleviating the symptoms. For this purpose, the cornea of a donor is transplanted into the patient’s eye.If the surgery is successful, a complete recovery can take place. The transplanted cornea takes over all functions of the removed tissue. If complications occur or the new cornea is rejected by the organism, the prospects of recovery decrease drastically. Under certain circumstances, a new transplantation can be performed after some time. However, there are long waiting lists and a guarantee of success with a new procedure cannot be given in advance.
Prevention
Corneal opacification can be prevented in several ways. For example, the risk is already minimized by not wearing contact lenses, as these can cause infections in the eye. In general, one should try to treat the eyes with care and avoid injuries and inflammations. If foreign bodies get into the eye, a doctor should be consulted as soon as possible to avoid corneal clouding. An ophthalmologist should also be consulted if vision is impaired or other visual complaints occur. The disease usually progresses insidiously, which is why it is usually only recognized by those affected when it is already too late. A corneal clouding, which is hereditary, is difficult to prevent. However, the severity of the disease can be contained by early treatment. The same applies if the corneal opacity is caused by a disease.
Aftercare
In the case of corneal opacification, the measures of an aftercare prove to be relatively difficult in most cases, since a complete healing cannot always be achieved in the process. The earlier the disease that is diagnosed and treated in this case, the better is usually the further course, so the patient should contact a doctor at the first symptoms of this disease. In most cases, the disease can only be completely cured if a donor cornea is available and can be transplanted. This procedure is usually performed under general anesthesia and proceeds without complications. The affected person must take care of his or her eyes after the procedure and not expose them to severe eye damage. The affected eye is then accustomed to ordinary eyesight over time. Furthermore, it is often necessary to take antibiotics to prevent inflammation. The affected person should pay attention to a correct dosage and also to the regular intake of these medications. They should also not be taken with alcohol. Since the corneal opacity can also lead to psychological upsets or depression, intensive and loving conversations with one’s own family or friends are very useful.
This is what you can do yourself
Because corneal opacity manifests itself differently in each patient, the options for self-help in everyday life vary considerably. In cases of mild corneal opacity, where there is still a possibility of regression, patients take special precautions to protect the eye. Thus, it is important to protect the diseased eye from overexertion. Such overexertion is caused, for example, by strained and prolonged staring at various screens, such as when working at a computer or watching television. In addition, the eye must also be protected from stress caused by weather conditions, such as wind and direct sunlight. Transferred to indoor areas, too bright light is also to be avoided. Patients with corneal opacities should initially refrain from wearing contact lenses until the doctor gives his or her explicit consent. Meticulous eye hygiene protects the eye from infections that may further aggravate the corneal opacity. In cases of severe corneal clouding with considerable limitations of vision, it is important for the affected person to come to terms with the situation and to take adequate precautions as far as possible. This is especially true at home, where orientation can be improved by changes in furnishings or stronger color contrasts. Therapeutic offers support the patient in training his other senses more strongly.
