Progressive Replacement of Oral Mucosa by Conjunctiva in Osteo-Odonto-Keratoprosthesis

Purpose: In a Strampelli osteo-odonto-keratoprosthesis, a patch of oral mucosa is frequently used to cover the ocular surface after implantation of an osteodental lamina into the eye. In many cases, gross modifications inthe eye covering become apparent a few years later. The aim of this study was to investigate the histologic findings in the clinically modified ocular surface. Method: Biopsies were performed in 7 patients at the junction between the osteodental acrylic lamina and surrounding modified oral mucosa, during surgery for local plastic reconstruction or positioning of antiglaucoma silicone tubes. Specimens were examined by light microscopy. Results: Six of the 7 clinically modified specimens corresponded microscopically to conjunctiva. Typical oral mucosa could still be observed overlying the osteodental acrylic lamina. Conclusions: The production of local regulatory factors is a possible explanation for the survival of oral mucosa over the osteodental acrylic lamina, whereas their absence in distant areas may have induced the oral mucosa to transdifferentiate into a conjunctival-type lining. Alternatively, conjunctival regrowth from forniceal stem cells should be taken into consideration.