Osteo-odonto-keratoprosthesis (OOKP) (also known as "tooth in eye" surgery) is a medical procedure to restore vision in the most severe cases of corneal and ocular surface patients. It includes removal of a tooth from the patient or a donor. After this, a lamina of tissue cut from the tooth is drilled and the hole is fitted with optics. The lamina is grown in the patients' cheek for a period of months and then is implanted upon the eye.

Indications and prognosis

An operation to graft the OOKP is undertaken in severe pemphigoid

Pemphigoid

Pemphigoid is a group of uncommon and rare autoimmune blistering skin diseases. As its name indicates, pemphigoid is similar to pemphigus, but, unlike pemphigus, pemphigoid does not feature acantholysis....

, chemical burn

Chemical burn

A chemical burn occurs when living tissue is exposed to a corrosive substance such as a strong acid or base. Chemical burns follow standard burn classification and may cause extensive tissue damage. The main types of irritant and/or corrosive products are: acids, bases, oxidizers, solvents,...

s, Stevens–Johnson syndrome, trachoma

Trachoma

Trachoma is an infectious disease causing a characteristic roughening of the inner surface of the eyelids. Also called granular conjunctivitis and Egyptian ophthalmia, it is the leading cause of infectious blindness in the world...

, Lyell syndrome

Toxic epidermal necrolysis

Toxic epidermal necrolysis is a rare, life-threatening dermatological condition that is usually induced by a reaction to medications...

 and multiple corneal graft failure.

There is a significant risk of anatomical failure of lamina in the long term, estimated at about 19% in a small study, with the main risks being laminar resorption

Resorption

Resorption is a process by which a structure is remodeled.Types include:* Bone resorption* Root resorption...

, particularly in allografts, and glaucoma

Glaucoma

Glaucoma is an eye disorder in which the optic nerve suffers damage, permanently damaging vision in the affected eye and progressing to complete blindness if untreated. It is often, but not always, associated with increased pressure of the fluid in the eye...

. Another, bigger study comparing OOKP with the lesser known osteo-keratoprosthesis (OKP) in 145 and 82 patients and follow-up terms up to 10 years yielded following statistics:

• 10-year anatomical survival: 66% for OOKP and 47% for OKP,
• 2-year functional survival: 63% for OOKP and 49% for OKP,
• 10-year functional survival: 38% for OOKP and 17% for OKP,

with functional survival defined as best corrected visual acuity above 0.05. A long-term study of 181 patients puts the chances of retaining an intact OOKP after 18 years at 85%.

Procedure

OOKP is a complex two stage operation which was pioneered in Italy in 1963 by professor Strampelli.

Stage 1 of the surgery involves 5 separate procedures:

1. The eye is opened up and the entire inner surface of the eyelids, corneal surface and all scar tissue is removed
2. Inner mucosal lining of the cheek is transplanted onto the new surface of the eye
3. A canine
   Canine tooth
   In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, fangs, or eye teeth, are relatively long, pointed teeth...
   
    or premolar
   Premolar
   The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...
   
   tooth and part of the adjacent bone and ligaments are removed
4. A bolt-shaped structure is fashioned from the tooth-bone complex which is fitted with a plastic optical cylinder
5. The tooth-bone-cylinder complex is implanted into the patient's cheek to grow a new blood supply

Stage 2 (about 4 months later) involves 2 separate procedures:

1. The cheek mucosal lining over the eye is opened and the inner contents of the eye are removed
2. The tooth-bone-cylinder complex is removed from the cheek and inserted into the eye, the mucosal cheek lining is replaced over the implant.

At the end of the procedure, light can now enter through the plastic cylinder, and the patient is able to see through this cylinder with good vision.

External links

• Blind man has sight restored by having tooth implanted in his eye – Article about a man receiving this procedure
• Yeshiva World News – story about blind man receiving this procedure