anillos_intracornealesIts purpose is to correct keratoconus, totally or partially, improving visual acuity in most cases. It is a corneoplastic surgery because its main purpose is to correct the deformity of the cornea. Cylindrical segments of plastic are placed in the cornea in the shape of a full ring or half-ring, as appropriate. They are implanted under anesthesia with drops and the patient can return to his normal activities in four days. Although rings have high tolerance, they can be removed without difficulty if necessary. Keraring rings assume that the greater the thickness, the greater the correction; also, the smaller diameter of the implanted segments, the greater the dioptric correction. They modify the tensional forces on the tissues and maintain corneal sphericity. In turn, they change the forces between the distal ends of the segments lifting the tissue comprised between them. The surgery is ambulatory, that is, that the patient leaves the clinic the same day of the operation, after a 30-minute observation period following anesthesia with pseudoanalgesia administered by an anesthesiologist to reduce patient’s anxiety. Topical anesthesia is also administered by a few eye drops in both eyes at once, because the procedure does not require the use of any dressing. It is important that the patient is accompanied by a person of trust. Once the anesthetic drops have been applied, a 1-mm incision will be made in the peripheral cornea to form two semicircular tunnels where the rings are inserted.