Minimum corneal thickness for LASIK operation It has sometimes been seen that in the initial tests and corneal photographs for refractive error procedures such as PRK, Femto LASIK and Smile, the doctor says a term called thinness of the cornea and the impossibility of surgery. The cornea is the transparent part of the eyeball, which is located in the anterior part (the front part of the cornea is 1.1 mm). And its transparency is due to the lack of blood vessels in its tissue.. 1- Protection of the living and delicate structures inside the eye 2- Refraction of light rays into the eyeball The refraction of light rays is done by the curvature of the anterior surface of the eye, which is in the form of a convex lens...if this curvature is not normal, the cornea either becomes more convex (nearsightedness) or refracts the light to the eyeball (telescope) from the cornea tissue with less convexity. Corneal tissue consists of five layers, from outside to inside: 1 ... Epithelium 2 ... Bowman's layer 3 ... stroma 4 ... members of the squad 5... endothelium In LASIK (PRK) surgery, the epithelium, which is the most superficial layer of the cornea, is removed by the surgeon with a surgical instrument. The thickness of the normal cornea is about 535 microns. Usually, thicknesses below 500 microns in the cornea are called thicknesses below 500 microns, if there are different thicknesses and types of corneas in different people. With appropriate and normal indicators, the thickness of the cornea is at least between 480 and 500 microns, people have an indication for LASIK surgery. This thickness is reduced after the LASIK procedure. The minimum thickness that must remain in the cornea after the LASIK operation for a person to have an ideal and safe surgery is about 400 microns. According to the number of eyes and the thickness of the cornea and the calculations made by the doctor and the laser device, it is determined whether the patient is suitable for laser eye surgery or not.

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