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Biomedical subjects

M Filipec

Publications and source records attributed to M Filipec.

46 records · Page 3Linked to original sources

[Surgery in sequelae of chemical and thermal burns of the eye].

The treatment of sequelae of chemical and thermal burns of the eye is sometimes very difficult. Previous to a event, keratoplasty all symblephara have to be removed. If there is no conjunctiva, transplantation from the second eye or from a donor is necessary. A method of transplantation of donor conjunctiva with a corneal lamella has been worked out as preparation for keratoplasty. Epithelium than can migrate to the transplant. In quantitative or qualitative alterations of the tears, the condition can be improved by soft contact lenses. In about one third of serious burns longtermed good results can be gained.

Adult↗

Specular and scanning electron microscopy in diffuse silicone keratopathy.

In a 50-year-old man, penetrating keratoplasty was carried out to treat a diffuse silicone keratopathy that developed 2 years after a pars plana vitrectomy combined with an intravitreal silicone injection for a complicated retinal detachment in the only aphakic eye. At 2 weeks after the intravitreal silicone injection, specular microscopy revealed a mild pleomorphism in the corneal endothelium and an endothelial cell loss of 26%. After 5 months, a small silicone drop floated in the anterior chamber and the first signs of diffuse keratopathy were observed. At the same time, specular microscopy revealed severe damage to the endothelial cells and a cell loss of 69%. After the keratoplasty, scanning electron microscopy of the corneal button showed a filamentous structure of the posterior surface of the cornea, with fibroblast-like cells; the endothelial cells were absent.

Anterior Chamber↗

Specular microscopy of the corneal endothelium after liquid silicone injection into the vitreous in complicated retinal detachments.

Twenty-one patients were followed up for at least 6 months after pars plana vitrectomy and liquid silicone injection into the vitreous for complicated retinal detachment by means of specular microscopy. In 17 eyes without silicone penetration into the anterior chamber, only insignificant changes were observed. In contrast, in 4 eyes, where a large drop of liquid silicone penetrated into the anterior chamber, the cell densities rapidly decreased to critical values and a marked pleomorphism of large endothelial cells with abnormal intracellular details indicated serious damage of the surviving cells. A characteristic structureless reflecting layer with contourlike lines in some areas of the specular image was a newly observed bizarre change that was caused by the replacement of the anterior chamber fluid by liquid silicone with markedly different optical properties.

Adolescent↗

The effect of liquid silicone on the corneal endothelium in rabbits. A comparative specular microscopic and histopathologic study.

Specular microscopic and histopathologic findings in the corneal endothelium were compared after the injection of liquid silicone into the anterior chamber of both eyes in 15 rabbits. The findings demonstrated serious damage to the endothelium in the area of contact of liquid silicone with the posterior surface of the cornea and disclosed some problems in the interpretation of specular microscopic findings. An abnormal endothelial mosaic can be probably found even in a zone of preserved intercellular borders or in a zone with a relief of the bases of extinct endothelial cells.

Animals↗

The development of in vitro biocompatibility tests for the evaluation of intraocular biomaterials.

Recent developments in ocular implant technology require the in vitro evaluation of ocular compatibility in early stage development programs. This requires an understanding and appreciation of the biological interactions which occur in the ocular environment and their relevance with respect to the clinical complications associated with surgical implantation of devices. This paper describes the development of a series of clinically reflective in vitro assays for assessing the potential ocular compatibility of novel intraocular lens materials. Staphylococcus epidermidis attachment, fibrinogen adsorption, mouse embryo fibroblast 3T3 adhesion and proliferation, primary rabbit lens cell adhesion, human peripheral blood macrophage adhesion and granulocyte activation tests were employed to evaluate two widely used intraocular biomaterials poly(methyl methacrylate) (PMMA) and silicone, and a novel biomimetic phosphorylcholine-based coating (PC). The performance of these materials in the in vitro assays was compared to their ability to reduce postoperative inflammation in vivo in a rabbit model. The results demonstrated that the in vitro assays described here are predictive of in vivo ocular compatibility. These assays offer a more relevant means of assessing the ocular compatibility of biomaterials than those presently required by the authorities for regulatory approval of medical devices and implants.

Journal Article↗