Corneal diseases

The cornea is the curved frontal part of the outer sclera, that is covered in tears. It covers the iris and the pupil with a transparent dome. The cornea and the eye lens make up the optical system, which focus a clear image of the environment onto the retina. Compared to a photo camera, the cornea is similar to the objective. It is layered and the most inner layer (corneal endothelium) is central for clear sight. It governs the fluids of the cornea and maintains its transparency. The outer layer (corneal epithelium) protects the cornea from infections.

Illnesses lead to cloudiness of the cornea. There are various reasons and the following are the most common ones. Some degenerations of the cornea are caused by age-related changes of the cornea, lesions, etc. Innate deformations of the cornea are called corneal dystrophy. Infections are called keratitis and can be caused by herpes, virus, bacteria, or fungal organisms. Lesions and corrosion are other common cause of corneal diseases. The sight is affected by corneal diseases, which can lead up to blindness. Affected people notice first a cloudy range of vision.

In early stages eye drops may help. In case of chronical cloudiness, a cornea transplantation may help, in which the old cornea is cut out and replaced by a donated cornea from a dead person. This operation shows only rare cases of rejection of the donated organ. In such a case the cornea is surgically replaced again. In contrast to other organ transplants, a cornea transplants aftercare can be fully covered with only eye drops.

Treatments of corneal diseases, which only affect single layers, are called lamellar keratoplasty. Only affected layers are removed. This surgery is technically more challenging, but the body shows no signs of rejection.

Diseases that only affect the outer layer of the cornea can be treated with a laser or mechanically. A transplantation is not needed.