Intro
Osteo-odonto-keratoprosthesis, also known as “tooth in eye surgery” is one of the most amazing and innovative procedures ever to be effectively performed. The eyes and eyesight are arguably the most imperative to us out of all the five senses, yet eyesight is one of the senses that is most commonly taken away from patients. OOKP presents a curious and inventive solution for restoring the eyesight of ailing patients, with a surprising element being the fact that the OOKP was developed in 1963, over 60 years ago now. The sheer ingenuity of this particular procedure would make it seem as though it was one of the “newly” created surgeries, yet it has been in practice for a relatively long time. Let’s break down what the procedure is, why it is performed, and the actual surgery itself.
What is OOKP?
Osteo-odonto-keratoprosthesis, also known as OOKP, is an advanced optical procedure that is most commonly used to treat and partly cure vision loss in the eyes of a patient. Although it may sound almost unbelievable at first, this surgery consists of using and extracting a patient’s tooth in order to help them with their vision. The full procedure will be outlined in detail in our section about the steps of the procedure of keratoprosthesis, but at a glance, a piece of the patients canine tooth is extracted (note: this can be substituted by a small piece of the tibia if the patient’s canine teeth are not ideal, although using a piece of the canine tooth is the preferred option). A cylindrical lens is then inserted into the piece of the canine tooth, which is then in turn implanted into the eye of the patient. This process is the foundation for creating an artificial cornea for the patient that will hopefully make their vision, and quality of life as a whole, a great deal better.
Why perform OOKP? (Indications/contradictions)
OOKP is only performed in patients with bilateral corneal blindness, which means that the loss of vision affects the corneas of both eyes, not just a single one. Reasons that OOKP would be performed are because of reasons that cause bilateral corneal blindness that include:
- Critical stages of Stevens Johnson syndrome
- Physical injury to corneas
- Thermal injury to corneas
- Chemical injury to corneas
- Loss of eyelids (drying of the eyes)
- Ocular damage is limited to ONLY the corneas (less common)
*This is only a short list of SOME of the reasons to perform OOKP, as the complete list is much longer.
Only one of the patient’s eyes will be restored during Osteo-odonto-keratoprosthesis. The reason that this is the fact after bilateral corneal blindness being a necessity is because if the patient still has one healthy eye, OOKP would most likely not be needed, as it is a generally intrusive procedure. Doctors consider the untouched eye to be somewhat of a “backup”, in case something goes wrong in the procedure on the first eye, as it is an intricate procedure that can go wrong at any step along the way. In addition, another lesser known prerequisite for OOKP is the fact that the visual acuity of the patient must be less than 1/20. Contrary to this, some of the main reasons NOT to perform keratoprosthesis is as follows:
- The patient is currently not looking to improve their vision levels
- If there is no want to improve the vision, surgery is not needed
- The patient has not reached adulthood yet (<17 years old)
- Patients bones are still growing, risk of “bone turnover”
- Smoking/tobacco use in general
- Detached retinal nerve
*This is only a short list of SOME of the reasons to not perform OOKP, as the complete list is much longer.
What is Stevens Johnson Syndrome?
A name of a syndrome that comes up quite often in the conversation about OOKP is Stevens-Johnson syndrome, also known as SJS. This particular syndrome is first characterized by flu-like symptoms, followed by the patient breaking out in a rash and subsequent blisters. In the acute stages of SJS, it is possible for a patient to go blind, which is where OOKP goes in.
Surgery Breakdown
This surgery can be broken down into four main steps:
- Extracting the canine tooth, removing the ocular surface, and inserting the cylindrical lens into said part of tooth
- Harvesting tissue from the inside of the patient’s lip (buccal mucosal graft) to cover the eye
- The piece of tooth (the lamina) is implanted into the patient’s cheek in order to vascularize for a period of 2-4 months. (www.longdom.org)
- The lamina is retrieved after the appropriate time and is thoroughly inspected before continuing with the procedure. The cornea is then exposed, and the prosthesis is then placed into the opening of the eye
Wrap-up
Osteo-odonto-keratoprosthesis is an intriguing, curious surgery that has improved the lives of many during its existence. Although that same existence might prove to be a deterrent to some, as the very notion of putting a piece of your tooth in your eye might be frightening, the good that it can and already has done in this world is more than enough proof of its validity in helping people.
Vocab
Tibia: The “shinbone”, located in the lower part of one’s leg.
Cornea: The “window” in the front of one’s eye, clear and made out of a tough tissue
Bilateral: Relating/affecting two or both sides
Buccal: Relating to the cheek and areas of close proximity
Sources
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5903185/
https://www.longdom.org/open-access/osteoodontokeratoplasty-a-review-47843.html
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