[Keratoprosthesis in cornea and ocular surface diseases].

In 1771, Guillaume Pellier de Quengsy,1 an ophthalmologist, proposed for the first time the possibility of substituting opacifie corneal tissue by “an artificial cornea”. The proposal was for transparent glass plates to substitute the opaque cornea in order to enhance the transparency of optic media. Improvements in topical and systemic immunosuppression and limbus transplant techniques for treating diseases involving the ocular surface have limited the use of keratoprosthesis in recent years. At present, the number of specialists who perform this type of surgery falls short of forty all over the world.2 In Spain keratoprosthesis has been reported to be applied in only 2 ophthalmological clinics. Even so, corneal prostheses subsist as a therapeutic option for patients with a high risk of post-surgery immunological rejection. At present several types of surgical techniques are utilized for implanting keratoprosthesis, i.e. osteo-odontokeratoprosthesis and the Boston keratoprosthesis.2 In 1963, Benedetto Strampelli3 designed a cylindrical acrylic lens mounted on a support that was made with a tooth of the same patient. This was named as osteo-odontokeratoprosthesis and to this date it is considered to be the gold standard for severe corneal opacity with severe dry eye associated to a high risk of immunological rejection. In 1980, Dr. J. Temprano4 designed some modifications for Strampelli’s technique, including the use of tibia bone tissue for patients in whom it was not feasible to remove a tooth and the extraction of the lens (transparent or not) in order to avoid second interventions. This surgical technique was named as tibia keratoprosthesis. In 1992, after obtaining FDA approval, Claes Dohlman developed a new keratoprosthesis model: an acrylic lens with a diameter of 7.5 mm comprising 8 holes in the posterior part to enhance the biointegration of prosthesis. This keratoprosthesis model is the current design of the Boston type keratoprosthesis.5