Moorfields South has officially launched its new surgical pathway for the osteo-odonto-keratoprosthesis (OOKP) service at St. George’s Hospital, London, marking a major milestone in the treatment of severe corneal blindness. The first patient successfully underwent stage 1 OOKP surgery in November 2024, in collaboration with maxillofacial surgeons from St. George’s (Rahul Jayaram) and the Sussex Eye Hospital (Jim Herold). Later on, in March 2025 the patient underwent stage 2 OOKP surgery and recovered full vision.
OOKP – often called “tooth-in-eye” surgery – is used for patients with end-stage ocular surface disease.
In this interview, Alfonso Vázquez-Pérez – consultant ophthalmologist and clinical lead for the Moorfields OOKP Service – explains how the procedure has advanced, and underlines the multidisciplinary approach vital to its success.
Can you briefly explain what OOKP is?
Dr. Alfonso Vasquez-Perez: Osteo-odonto-keratoprosthesis was developed to restore vision in people who aren’t suitable candidates for traditional corneal transplants, often because their ocular surface is too damaged, dry, or scarred for a graft to survive. In the 1960s and 70s, Italian surgeons created an approach using natural tissues at a time when modern biomaterials didn’t exist. They discovered that dentine from a tooth was one of the most durable materials available. The technique involves creating an artificial corneal device made from dentine and bone, which is placed in front of the eye carrying a small optical cylinder providing a transparent window for vision. It’s a complex surgery that also requires reconstructing the ocular surface, which is why only a few centers worldwide perform it. Nonetheless, since the 1970s it has successfully restored full vision for many blind patients unsuitable for conventional corneal transplantation. The OOKP involves a multidisciplinary team including ophthalmic, maxillofacial, anesthesia and psychology specialists. The treatment consists of two surgeries: stage 1 and stage 2, separated by 3 months, and patients recover vision only after stage 2.
Which patient profiles are most suitable for OOKP surgery?
Patients referred for OOKP are those who have no remaining options for vision restoration, with severe dryness of the ocular surface and who often have received multiple failed corneal transplants. The most common group includes people with severe bilateral chemical burns, or uncommon autoimmune conditions which destroy the ocular surface and leave it dry and heavily scarred. In these cases, standard transplants always fail, leaving artificial corneal devices – keratoprostheses – as the only option.
There are several keratoprosthesis designs, but two are most widely used: the Boston Type I, which still requires a reasonably healthy and moist ocular surface, and the Osteo-odonto-keratoprosthesis, which is designed specifically for patients who are completely blind in both eyes and have a dry, severely damaged surface where other treatments cannot succeed.
Typical indications for OOKP include people with autoimmune conditions such as Stevens–Johnson syndrome and ocular cicatricial pemphigoid, which cause scarring similar to that seen after chemical injury.
We also need to determine whether the patient’s tooth is suitable, of course. We usually use the canines, which are better for this operation. But if a patient does not have a suitable tooth, sometimes we can't do it.
What have been some recent innovations in OOKP?
One of the most significant developments has been in diagnosing and managing early complications. OOKP patients inevitably face ongoing issues, and glaucoma is the most common – affecting around 80–85% of patients.
Diagnosis used to be extremely difficult because the surgery reconstructs the eye’s surface using buccal mucosa (inner cheek lining). This means the eye no longer looks or behaves like a normal eye: you can’t measure intraocular pressure, and glaucoma drops don’t penetrate the thick buccal mucosa and do not work, so treatment must be surgical.
Now, with improved imaging and more sensitive scans, we can monitor the optic nerve much more effectively and detect early glaucoma changes. In addition, we have developed an endoscopic surgical approach, working with my consultant colleagues at Moorfields from vitreoretinal (Rob Henderson) and glaucoma (Nick Strouthidis). Using a tiny camera in an optic fiber, which is introduced inside the eye, we can directly visualize the optic nerve and retina, and perform procedures such as tube shunt surgery when needed. This ability to look inside the eye accurately and intervene safely is one of the major advancements in OOKP care.
The other innovation we’re working on involves removing the vitreous jelly during OOKP stage 2 surgery. In the past, this was very difficult and risky. Ideally, these patients should undergo a conventional pars plana vitrectomy, but the OOKP optical window is only 3.5 mm wide. That makes it almost impossible for a retinal surgeon to safely visualize and treat the peripheral retina. With a new approach – partial open sky pars plana vitrectomy – we can now remove the vitreous safely during the second stage before the tooth device is placed. This offers long-term benefits by reducing the risks of retinal detachment, chronic vitritis, and glaucoma. The vitreous often blocks glaucoma drainage tubes, making them ineffective, so removing it is important.
We are also exploring alternative materials for the OOKP lamina because not all patients have suitable teeth. We are now starting a new approach using calvarial bone (from the skull) to make the artificial corneal device (lamina), which our maxillofacial colleagues use successfully in other procedures. This bone is strong, resistant, and readily accessible to harvest.
Given that the procedure involves multiple surgical specialties, how do you coordinate between ophthalmic, maxillo-facial, and psychological teams?
This is a major undertaking, and it can’t be delivered by an ophthalmology service alone. Fortunately, Moorfields has a strong network and operates at a network site at St George’s Hospital in London – a large general referral center where the ophthalmology department is run by Moorfields. We had already collaborated with maxillofacial surgeons there on previous complex cases, often working alongside ENT and maxillofacial teams.
When the OOKP service in Brighton came to an end, it created an opportunity to rethink how we delivered the procedure. We had already been involved in other complex work, such as transferring nerves to restore sensation to the eye, so we had an established framework – or “umbrella” – for multidisciplinary collaboration.
I’ve continued working closely with these maxillofacial colleagues, for whom much of the required surgical work is routine. At Moorfields, the keratoprosthesis service also includes dedicated Boston Type I specialists, as well as retina and glaucoma surgeons specifically assigned to these patients. Bringing everyone together for this new project wasn’t simple, but because the expertise already existed within the network, assembling the team and establishing the service ultimately proved less challenging than we had initially expected.
What are your findings in terms of OOKP patients’ visual outcomes, quality of life, and complication rates?
The outcomes are remarkable. Most patients come to us with only light perception, often after years or even decades of blindness in both eyes. If the retina and optic nerve are healthy, these patients can often achieve vision as good as 20/20. They will still need glasses, but the optical media itself is completely clear, with no cataract or opacity allowing for excellent visual potential. However, the optical cylinder is quite narrow, so the field of vision feels restricted. Some patients may be borderline for driving.
If there is existing retinal or optic nerve disease, the final vision will be less than ideal but still they can have a significant visual improvement. The challenge is that, before surgery, the front of the eye is so scarred that we cannot see inside to properly assess the retina or optic nerve. We perform extensive testing – ultrasound scans, electrodiagnostics, and a detailed history – to estimate visual potential. If the results suggest any reasonable chance of improvement, we still offer the procedure, while explaining that pre-existing conditions such as glaucoma or retinal damage may limit the final outcome. Even so, most patients experience a meaningful improvement in vision that significantly enhances their daily functioning.
How do you see OOKP fitting into the broader landscape of corneal and ocular surface reconstruction?
We’re working with the Department of Biomaterials at University College London, which develops biomaterials for many medical specialties, including bone and dental substitutes. Although OOKP can restore vision, it remains an invasive surgery because we must harvest a tooth and surrounding bone. A synthetic or highly biocompatible material that integrates well in the ocular surface could simplify the operation and reduce its complexity. We’ve begun early planning meetings with experts to explore this, and I’m hopeful that developing such a material will be a major contribution by the end of my career.
We’re also exploring hybrid techniques. Alongside the Boston Type I keratoprosthesis, there is the synthetic Boston Type II device. For patients without suitable teeth, or older patients with weakened bones, we may be able to adapt the Type II device and combine it with buccal mucosa and the same vitreous-removal approach used in OOKP. Some centers have begun similar work, though not yet in Europe, and we believe it could be an important advancement. Traditional OOKP can last decades – some patients from 1999 still have 20/20 vision – but even a hybrid that provides five good years of sight for an older patient would be immensely valuable.
Is there anything you’d like to add?
I’d like to acknowledge all my multidisciplinary team members and especially to my "great ally" in this journey of setting up the OOKP Service – Rahul Jayaram, Consultant Oral and Maxillofacial Surgeon at St. George’s Hospital.
