Abstract
Purpose: :
To evaluate the pathology findings of the intrastromal Poly-methyl methacrylate, (PMMA) ring-segments implanted in human cornea.
Methods: :
Human cornea implanted with PMMA ring-segments (Ferrara ring, Ferrara & Hijos SL, Boecillo, Spain) from patient with keratoconus were analyzed for pathology studies: Light microscopy (hematoxylin-Eosin, Gomori Tricromic) and inmunohystochemistry: SMA, CD 10, CD 8, CD 34, CD 68
Results: :
An atrophic epithelium and reduction in the number of keratocites were observed over the implant. Around the implant there is a de-orientation of the cells and hypercelularity that stain positive for SMA that mark the stromal cells as myofibroblast. Also, adjacent to the implants there are positive cells for CD 10 (neutral endoprotease), CD 34 (keratocites) and interesting, there are keratocites positive for CD 68 (macrophages).These findings suggest that ring segments implant modulate the epithelial and corneal stroma with atrophy of the epithelium and adjacent stroma and a great reaction of corneal keratocites around the ring segment.
Conclusions: :
Intra-stromal ring segments reduce the number of keratocites and epithelial cells and modulate the phenotype of keratocites with expression of markers for macrophages (CD 68), myofibroblast (SMA) and endoprotease (CD10).
Keywords: cornea: stroma and keratocytes • pathology: human • keratoconus