Influence of dacron tissue thickness on the performance of the Pintucci biointegrable keratoprosthesis: an in vitro and in vivo study.
OBJECTIVE
In 1979 Pintucci developed a biointegrable keratoprosthesis with polymethylmethacrylate optical cylinder integrated with a Dacron tissue-colonizable supporting element to avoid the complications caused by the interaction between the haptic element and the eye. The purpose of this article is to compare the colonization of three Dacron fabrics (thicknesses of 0.25 mm, 0.6 mm, and 1.4 mm) in vitro and in vivo to optimize the device performance.


METHODS
In vitro three different Dacron fabrics were cultured for 3 days with 3.5 x 10(5) human fetal lung fibroblasts and observed with a scanning electron microscope. In vivo three different Dacron fabrics were implanted on the sclera near the superior rectus insertion in the right eye of six albino rabbits and were observed after 4 days with light and scanning electron microscopy.


RESULTS
In the in vitro experiments, the cells were preserved and their structure was found to be normal. The 0.25-mm thick fabric was coated only on the surface, and the other fabrics were colonized in three dimensions. In the in vivo experiments, the 0.25-mm thick fabric appeared coated only on its surface. The other fabrics were three-dimensionally colonized and the Dacron filaments appeared embedded in neovascularized connective tissue with minimal foreign body reaction. The 1.4-mm thick colonized fabric showed a substantial loss of pliability.


CONCLUSIONS
Given that the 0.25-mm thick fabric was coated only by connective tissue, that the 0.6-mm and 1.4-mm thick fabrics were perfectly colonized, and that the 1.4-mm thick fabrics showed a substantial loss of pliability, the 0.6-mm thick fabric haptic part of the Pintucci keratoprosthesis is preferred. For 19 years, the 0.6-mm Dacron fabric Pintucci keratoprosthesis was implanted in 159 eyes with good results, overcoming the apparently inseparable difficulties represented by mechanical anchorage and biointegrability of a keratoprosthesis.
Pintucci
S
S
Laboratory of Ultrastructures, Istituto Superiore di Sanità, Rome, Italy.
Perilli
R
R
Formisano
G
G
Caiazza
S
S
D000818:Animals; D001672:Biocompatible Materials; D002478:Cells, Cultured; D003238:Connective Tissue / Q000648:ultrastructure; D003315:Cornea; D005333:Fetus; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D008168:Lung; D008855:Microscopy, Electron, Scanning; D011093:Polyethylene Terephthalates; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D011817:Rabbits; D012590:Sclera / Q000601:surgery
D001672:Biocompatible Materials; D011093:Polyethylene Terephthalates