Osteo-Odonto Keratoprosthesis (OOKP): A Review of Surgical Techniques and Clinical Outcomes

Osteo-odonto keratoprosthesis (OOKP) is a multi-staged procedure for the treatment of blindness due to bilateral severe endstage corneal disease. Developed by Strampelli over fifty years ago and modified thereafter by Falcinelli, the OOKP is by far the only keratoprosthesis that has been retained in eyes for over twenty to thirty years. This procedure can be performed in eyes with bone dry and keratinized ocular surfaces and basically consists of a optical cylinder help in place by a skirt of dento-alvelolar bone. This review describes the surgical technique of OOKP and the clinical outcomes reported by various series including the author’s personal experience with this keratoprosthesis. 1Cornea and Anterior Segment Services, L V Prasad Eye Institute, Hyderabad, India Corresponding Author : Sayan Basu, E-mail: [email protected] Received on : 25/01/2015, Accepted on : 03/02/2015 Conflict of Interest : None, Financial Disclosure : None O (OOKP) surgery is a technique developed half a century ago by the Italian ophthalmologist Strampelli and usesthe patient’s own tooth root and alveolar bone to support an optical cylinder.1 This multi-staged procedure is indicated in cases of severe bilateral corneal blindness, when conventional corneal transplantation or even the Boston type1 keratoprosthesis is doomed to failure. Although initially conceptualized by Pellier de Quengsy, a French ophthalmologist, the first keratoprosthesis implantation in a human was performed byNussbaum in 1855. This was a quartz crystal implant that remained in the eye forsix months. Subsequently owing to the inevitable extrusion of the early implants and also due to the increasing popularity of penetrating keratoplasty, the initial enthusiasm surrounding keratoprosthesis died down. However, as experience with penetrating keratoplasty grew, surgeons the world over realized that there were still some forms of corneal blindness that were not amenable to treatment by replacing the diseased cornea with a healthy donor cornea. Thus interest in keratoprosthesis was renewed and numerous designs and techniques were subsequently described.2 An ideal keratoprosthesis should be a suitable replacement of the cornea being optically clear, bio-integrable, resistant to infection and most importantly it should be longlasting.3,4Keratoprosthesis can be classified based on the material of the optical cylinder (optic) and the support for the optical cylinder (haptic).Most modelshave a nonbiological haptic(Boston KPro, Pintucci, Leon-Barraquer, Legeais and AlphaCor), while few use biologicalhaptics (Strampelli OOKP, Casey and Temprano).Among these the Boston type 1 keratoprosthesis is currently the most popular while the OOKP has the longest follow-up and best retention rate.The OOKP can also be used in bone dry eyes with keratinized ocular surface and it is the only potentially vision restoring surgery that is possible in such eyes. The original technique of OOKP described by Strampelli has been modified by Falcinelli to improve visual results and retention of thedevice.5,6 Therefore this technique is now also referred to as the modified OOKP or MOOKP.