What is Cornea?
The cornea is the transparent tissue in the front of the eye and is the most important crusher lens of the eye. The transparency of the cornea can be disrupted by many diseases. These diseases may be congenital, genetic or microbial. Certain diseases such as keratoconus may require corneal transplantation by altering the shape of the cornea.
The cornea is an opaque transparent layer of the eye, which is located in the front of the eye, which has the role of focusing the light and protecting it from external factors.
Corneal Examination Methods
A person without an ophthalmologist can evaluate the corneal transparency, the brightness of the surface, corneal injuries, corneal sensitivity with the help of a cotton rod. Ophthalmologists use devices to evaluate the morphology and function of the cornea;
Biomicroscopy: It is used for binocular examination of the cornea and other structures belonging to the anterior segment. Light beams of varying thickness can be sent from different angles and the cornea can be examined under the magnification of the biomicroscope. It is the most frequently used examination method.
Keratometry: Measuring the breaking power of the cornea. It is used before contact lens and intraocular lens implantation.
Topography: It is used in the topographic analysis of the front face of the cornea.
Pachymetry: Measurement of corneal thickness.
Specular microscopy: shows the number and structure of endothelial cells.
Estesisometry: It is used in evaluation of corneal sensitivity.
Corneal staining: Corneal defects can be seen with fluoresseine and rose bengal solution.
All corneal diseases that occur in the congenital or later years are treated by our cornea unit.
The most common corneal diseases;
Keratitis: Corneal inflammation is called keratitis. There are multiple variants and reasons. Early diagnosis of the disease is very important for the treatment.
Keratoconus: Keratoconus is the disease of the most prominent translucent layer of the eye, namely the progressive thinning and tapering of the cornea.
Generally, patients who are in adolescence are aware of their age of 20 years. It progresses between the ages of 20 and 40 and enters the stationary period after 40 years of age. Today, keratoconus disease is observed in one in every 2000 people in western societies. The incidence of keratoconus increases with each passing year. Progressive myopia and astigmatism, corneal thinning and tapering keratoconus disease, which starts to give symptoms, can be diagnosed early with very special tests.
Dry Eye Syndrome: It is caused by dry eyes due to lack of tears. Symptoms are stinging, redness and constant foreign body sensation.
The Structure of the Cornea
Corneal anatomically consists of 5 layers.
The regeneration ability is fast 5-6 rows of non-keratinized multilayered flat epithelium. The front face is covered with tears. Bowman Membrane-level sensory nerves end between epithelial cells. Bowman membrane underneath is firmly adhered to the basement membrane.
Stroma is the condensed front of the lamellae. After injury, it does not refresh, develops opacities (scar tissue) that can cause visual impairment.
It constitutes 90% of the corneal thickness. Collagen fibers forming the strom are uniform. From the limbus to the limbus without intersecting each other. They are located in the intermediate consisting of mucosaccharides. Stroma is poor in cells. These cells, called keratocytes, turn into fibroblasts in injuries and provide wound repair.
The endothelial cells are the basement membrane. According to the other layers of the cornea is more elastic. The stroma is not stuck. It can be easily stripped.
It consists of single-row hexagonal cells. They don’t multiply by mitosis.