Osteo-odonto-keratoprosthesis (OOKP), often referred to as “tooth in eye surgery,” is a highly specialized reconstructive procedure designed to restore sight in individuals with the most severe forms of corneal blindness. This technique is a last resort, reserved for patients who have exhausted all other conventional vision restoration options. The procedure involves creating a unique prosthetic device using the patient’s own dental tissue, which is then surgically implanted to replace the damaged, opaque cornea. The entire process is a multi-stage operation requiring a collaborative effort between ophthalmic and maxillofacial surgeons. It is a medical intervention aimed at providing visual function where the eye’s natural surface has been rendered irreversibly non-functional.
Who Qualifies for OOKP
This form of treatment is strictly limited to patients suffering from end-stage ocular surface disease (OSD), a condition where the eye’s front surface is so severely damaged that it cannot support a traditional donor corneal transplant. Standard corneal grafts fail in these eyes due to chronic inflammation, lack of a healthy tear film, and severe vascularization of the tissue. The eye surface is too hostile for foreign tissue, leading to rapid rejection and clouding of the graft.
The most common diagnoses necessitating OOKP include devastating injuries like severe chemical or thermal burns to the eye. Autoimmune conditions such as Stevens-Johnson syndrome (SJS) and ocular cicatricial pemphigoid also create an environment of unrelenting inflammation and scarring that disqualifies patients from conventional surgery. In these cases, the eye’s natural healing mechanisms are permanently compromised.
Patients considered for OOKP must have a functional retina and optic nerve, as the procedure only addresses the opacity of the front of the eye. If the visual pathway at the back of the eye is damaged, restoring a clear optical path will not lead to restored sight. Candidates are typically those who have suffered bilateral blindness, meaning the condition affects both eyes.
Preparing the Biological Components
The unique aspect of this procedure is the use of the patient’s own tooth and its surrounding bone as the biological foundation for the prosthetic. A canine tooth is typically selected due to its large, strong, single root, which offers the best structural support. Using the patient’s own tissue, specifically the dental root and bone, makes it far less likely to be rejected by the body’s immune system than a synthetic material or donor tissue.
The tooth and a segment of its supporting alveolar bone are extracted as a single unit. This autograft is then shaped into a flattened rectangular piece called a lamina. A hole is drilled through the lamina to accommodate a clear acrylic optical cylinder, which will function as the new lens.
Once the optical cylinder is cemented into the lamina, the entire assembly is implanted beneath the skin, often in the patient’s cheek or shoulder, for approximately two to four months. This subcutaneous incubation period encourages the surrounding soft tissue to grow onto the dental root structure. The resulting tissue coverage provides a robust, vascularized surface that helps the implant integrate securely and resist breakdown once it is placed into the eye.
The Multi-Stage Surgical Procedure
The OOKP procedure is separated into two surgical stages, often spaced months apart to allow for tissue healing and integration. The first stage focuses on preparing the eye to receive the implant. During this initial operation, the diseased and scarred corneal and conjunctival tissue is removed, and the eye’s interior structures, including the lens and iris, are often cleared to create a direct path to the retina.
A crucial part of Stage One involves harvesting a buccal mucosal graft from the inner lining of the patient’s cheek. This flap of tissue is then transplanted onto the surface of the prepared eye, covering the entire area where the cornea once was. This vascularized mucosal layer provides a stable, moist, and self-renewing covering that will protect and nourish the tooth-based prosthetic.
The second stage of the surgery occurs several months later, after the tooth-lamina has developed a healthy vascular supply beneath the cheek skin. The surgeon removes the integrated tooth-bone-lens complex from its temporary location and prepares to implant it into the eye. A small incision is made in the center of the previously placed buccal mucosal graft, where the lamina will be inserted into the eye globe.
The lamina is positioned so the clear acrylic optical cylinder projects through the small opening in the mucosal graft, allowing light to pass directly into the eye. The edges of the lamina are then secured beneath the mucosal layer, which is sutured tightly over the entire structure. This final step seals the prosthetic into the eye, providing the mechanical stability and biological anchor necessary for sustained visual function.
Recovery and Visual Restoration
Following the second stage of the surgery, patients typically experience a return of light perception. The improvement in vision can be substantial, with many patients achieving a level of sight that allows them to read large print and recognize faces. However, the restored vision is not comparable to normal sight; because the optical cylinder is very narrow, patients experience a limited field of vision, similar to looking through a telescope or a porthole.
Post-operative care involves long-term management to maintain the integrity of the implant and prevent complications. Because the buccal mucosal graft covers the prosthetic, it must be kept healthy and moist to prevent ulceration or drying, which could lead to infection. The most common long-term complication is the development of secondary glaucoma, an increase in pressure within the eye, which requires continuous monitoring and management, often with medication.
The durability of the OOKP is an advantage over other artificial corneas in high-risk patients. Long-term studies show that the anatomical survival rate for the implant, meaning it stays securely in place, is very high, with prosthetics remaining functional for decades. This sustained retention rate offers a permanent solution for individuals whose severe ocular surface disease would otherwise condemn them to irreversible blindness.