Cornea is the transparent front part of the eye that covers the pupil and the iris (that is, the colored part of the eye). Below you’ll find accurate descriptions about corneal diseases and injuries, artificial cornea, Boston Keratoprosthesis, corneal laser surgery, and also about the latest news on the minimally invasive or artificial corneal transplant. Definitions are given by Dr. Badalà, who works as an ophthalmologist in Milan and Catania.
Cornea related injuries and diseases could be: cornea guttata, corneal dystrophy, corneal ulcer, keratoconus, corneal abrasion. All of these can lead to a loss of corneal transparency.
In these cases, the most common treatment consists in a corneal transplant, that makes it possible to see well again. If the disease is catched early, it is even possible to avoid the transplant altogether with a medical therapy.
If transplant fails, you can resort to artificial cornea, via the Boston Keratoprosthesis: the artificial cornea can give a new hope to many patients.
Cornea shields the inside of the eye just like the glass of a watch. It is composed of several layers; from the outside, there are, in order:
Some corneal diseases affect the whole cornea, some others only the superficial part or the most inner layer (endothelium).
Some corneal disease have a genetic component and are linked to the patient’s family history; this is why, in case of relatives that have such diseases, it is best to see an ophthalmologist and, if that’s the case, diagnose corneal diseases early on.
This is even most advisable in case of cornea guttata or keratoconus, where genes responsible for the disease have been identified.
Corneal injuries and diseases such as: guttate cornea, corneal dystrophy, corneal ulcer, keratoconus, and corneal abrasion can lead to loss of corneal transparency.
In these cases, the main therapy is corneal transplantation, which allows, by replacing the diseased cornea, vision to be regained. If action is taken in time, however, it is possible with medical therapy to avert the need for corneal transplantation. When corneal transplantation also fails, artificial cornea can be used with Boston keratoprosthesis surgery. This surgery makes it possible to restore hope to many patients today.
Cornea guttata is an often familial corneal disease in which the cornea loses its transparency with time. Usually more than one member of a family has this condition. In guttate cornea, the inner layer of the cornea called the endothelium is marred as if it had been hammered, and areas of healthy endothelium and marred areas are observed.
In guttate cornea the symptoms usually occur in adulthood when one notices variability in vision. It is usually worse on awakening and better in the evening. Other symptoms of guttate cornea may be a discomfort and vision of halos around lights, in advanced stage you may also have foreign body sense or pain.
The ruined endothelium causes the cornea to no longer be impermeable. Thus in guttate cornea the cornea increases in thickness because it fills with water coming from inside the eye.
You may also see blisters forming on the cornea (bullous keratopathy). Useful is the performance of corneal pachymetry, that is, measurement of corneal thickness to monitor the status of the guttate cornea and corneal edema.
Initially, it can be treated with medical therapy with hyperosmotic agents that pull excess water out of the cornea and allow for improved vision even if only transiently. Later, replacement of the damaged endothelium by corneal endothelium transplantation using the DMEK or DSAEK technique is useful.
Corneal Abrasion – Scratched Cornea
Scratched cornea or corneal abrasion consists of the loss of the superficial layer of the cornea called the epithelium. It can be observed after trauma such as a finger in the eye, for example, or due to dystrophy of the cornea.
Corneal dystrophy often has a familial component. Usually the Bowman’s membrane of the cornea is ruined, which causes the corneal epithelium to be unstable and repeatedly peel off at the slightest trauma, such as opening the eyes at night. The symptom of scratched cornea or corneal abrasion is severe pain that improves by keeping the eye closed.
Treatment consists of bandaging and rest. The epithelium grows back on its own within a couple of days. Crucial, to avoid the risk of infection, is to have an eye examination. Those suffering from recurrent or relapsing corneal abrasion can have specific treatments such as:
Laser corneal surgery (PTK)
Superficial keratectomy with a diamond scalpel (diamond burr polishing).
Scratched cornea is a very painful condition, but it usually heals spontaneously within a few days. The cornea can be scratched during makeup, as a result of trauma or from a contact lens, or repeatedly in the case of corneal dystrophy.
Antibiotic eye drops should be used to prevent infection of the cornea, and usually keeping the eye closed provides relief and speeds healing. One should contact one’s ophthalmologist for appropriate treatment.
Corneal infections (keratitis, corneal ulcer) are often the result of improper contact lens wear and require great care. If not treated promptly, they can result in scarring of the cornea that limits vision. When faced with a red eye in a contact lens wearer, a corneal infection should be suspected.
Contact lens wear should be discontinued and the ophthalmologist should be consulted. Should a corneal scar form, it can be treated by a laser technique known as PTK or, in severe cases, by corneal transplantation.
Cornea Transplant Centers
There are numerous cornea transplant centers in Italy. It is worthwhile to rely on a cornea transplant center that performs all modern corneal transplantation techniques. The various types of corneal transplantation complement each other. Dr. Badalà performs this type of corneal transplant and all other methods for the treatment of corneal diseases in Milan and Catania.
Only a center with wide experience with all currently available methods, from lamellar corneal transplantation to artificial cornea, will be able to offer the most suitable solution in each individual case.
Corneal transplant centers that perform DALK anterior lamellar transplantation or posterior lamellar transplantation called DMEK are few and select. This is because these methods are technically complex but allow for faster recovery and fewer complications. Relying on an experienced center reduces the risks of Transplantation.
The main risks of corneal transplantation are divided into risks during the operation and risks after the operation.
Intraoperative risks can also be very high in the case of a traditional corneal transplant in which the entire cornea is replaced; in fact, the eye remains open without protection when the patient’s cornea is removed and then replaced with the new one. In these few moments, a serious complication of corneal transplantation can occur, which is called expulsive hemorrhage; fortunately, this is a rare complication of full-thickness corneal transplantation. This complication is almost absent in lamellar corneal transplantation.
The risks after corneal transplant surgery are mainly related to rejection. There is always a risk of rejection after corneal transplantation, yet this surgery has one of the highest success rates of all organ transplants. In lamellar transplantation such as DALK (deep anterior lamellar keratoplasty) or DSAEK (corneal endothelium transplantation) since the amount of tissue transplanted is less then the risk of rejection is also less.
Symptoms of corneal transplant rejection can be very mild such as a simple redness of the eye, this should never be underestimated in corneal transplant recipients, especially if the symptoms persist for a few days. In such cases, it is advisable to contact the ophthalmologist. Other symptoms may include photophobia (discomfort with light) or blurred vision.
Rejection therapy must be instituted promptly to be most successful and usually relies on cortisone-based eye drops, which can have cataract formation or glaucoma as side effects. In lamellar transplantation, the time of anti-rejection therapy is reduced with definite advantages.
Contacting an experienced center for transplantation is also crucial for the management of any rejection phenomena that if treated well leave no consequences otherwise can ruin the transplant altogether.