The cornea is the transparent, curved front part of the eye that serves to focus the light and protect the eye from outside factors, plays a major role in visual function of the eye, and it is the most important refracting lens of the eye. Transparency of the cornea can be impaired by many diseases. These diseases can be congenital, genetic or microbial.
Keratitis
Inflammation of the cornea is called keratitis. Transparent cornea tissue can be blurred, thinned or even ruptures due to keratitis.
Keratitis can be caused by bacteria, viruses, fungus or rheumatism.
Keratitis occurs with symptoms including pain, stinging, redness in the eye, blurred vision and white spots in the eye.
Bacterial Keratitis
Use of contact lenses without conforming to hygienic conditions, eye surgery, eye surface trauma (that sand gets into the eye, etc.) are the main reasons for formation of bacterial keratitis.
It is frequently treated with antibiotic drops on an outpatient basis.
Virus Keratitis
The most common types of virus keratitis are herpes keratitis and adenovirus keratitis.
Fungal Keratitis
It is treated with antifungal drugs in the long-term. Fungal keratitis leaving spots to the extent that vision is reduced in the corneal center is also treated by corneal transplant.
Keratoconus
It is a corneal disease in which the cornea thins and its shape becomes more conical than the normal curve; in other words, it is deformation of the cornea.
The disease has several reasons and patients usually have genetic predisposition. Allergic eye disorders, frequent rubbing of the eyes, myopia, astigmatism, and refractive impairments set the scene for the disease.
Keratoconus is a disease that progresses insidiously, and is not detected during routine eye examination.
Treatment methods can be listed as follows.
If the patient isn‘t suitable for contact lens use and isn't at an advanced stage of the disease, insertion of intrastromal corneal ring segments can be performed. Under anesthesia ensured by drops, corneal channels are created inside the cornea of the patient using laser. Special rings are placed in these channels. By the courtesy of these rings, current refraction is partly reduced and better vision is achieved as well as the rings correct the shape of the cornea, creating a better medium in case a need for glasses or contact lenses arises. The rings can be removed where necessary.
Corneal Transplant
Corneal transplant is the last treatment option in the latest stage of keratoconus.
Dry Eye Syndrome
It is caused by eye dryness associated with lack of teardrops. Its symptoms include stinging, redness and permanent foreign-body sensation.
Corneal Abrasion
It is an injury in the epithelium (scratch, peel or cut). Abrasions are usually caused by scratching with nails, paper, make-up brushes, peeling with a tree or bush branch, and then rubbing the eye. Certain eye diseases such as dry eye increase the risk of abrasion. Its symptoms include:
A special stain called fluorescein is used to detect an abrasion in the cornea. During treatment, the following methods are utilized;
Corneal Erosion
Cornel erosion arises from the failure of the cornea's surface layer to attach to the underlying tissue.
Symptoms of corneal erosion include:
Its treatment is the same as corneal abrasion but additionally an eye drops or ointments with salt solution are applied. If corneal erosion repeats, additional methods such as removal of damaged epithelium, ablation of a small layer of corneal cells by laser or creating small holes on corneal surface in order to support stronger bond formation between top layer of corneal cells and bottom corneal layer are applied.