Light microscopy and electron microscopic examination were carried out on the corneal buttons of two patients who required penetrating keratoplasty for treatment of corneal complication following the intraocular injection of silicone oil to repair recurrent retinal detachments in aphakic eyes. Light microscopic examination demonstrated increased cellularity and irregularity of collagen fibers of stromal layer, defect of endothelial cell layer and endothelial degeneration. Electron microscopy examination demonstrated marked decrease in endothelial cell population density, accompanied by flattening and thinning of the remaining cells and attenuation of cell borders. There were silicone droplets in the endothelial cell layer and collagenous layer posterior to endothelial layer. These findings are well correlated to clinical manifestation and are thought to be rather due to barrier effect of silicone oil than direct toxicity.
Adult ; Corneal Diseases/*chemically induced/pathology/surgery ; Descemet Membrane/ultrastructure ; Endothelium, Corneal/drug effects/surgery/ultrastructure ; Humans ; Keratoplasty, Penetrating ; Male ; Recurrence ; Retinal Detachment/surgery ; Silicone Oils/*adverse effects

The aim of this study was to evaluate the cellular response and morphological changes of cells on the intraocular lens(IOL) implanted over a course of time and to identify the basic mechanism of IOL adaptation to tissue reaction in the implanted eye by comparing polymethylmethacrylate (PMMA) IOL with heparin surface modified PMMA IOL. ECCE using Healon was done in 36 eyes of 36 rabbits. A heparin surface modified IOL was implanted in 18 eyes (Group I), while PMMA IOL was implanted into another 18 eyes (Group II). Corneal thickness and endothelial cell density were measured for 3 months. Postoperatively, the eyes were enucleated, and a cytopathologic examination of the cells on the surface of the IOL and their ultrastructural changes were observed with light and scanning microscope at various points of time. The findings of this present study suggested that heparin surface modified PMMA IOL reduced the degree of endothelial cell damage, postoperative tissue reaction, and pigment deposits on the surface of the IOL. These were statistically significant. The most important cell was considered to be the macrophage for the adaptation of IOL in the eye which gradually changedinto a fibroblast-like cell, giant cell and finally disappeared after forming an acellular membrane on the IOL.
Animals ; Cataract Extraction ; Cell Count ; Cornea/pathology ; Endothelium, Corneal/*pathology/ultrastructure ; *Heparin ; *Lenses, Intraocular ; Macrophages/pathology ; Materials Testing ; *Methylmethacrylates ; Microscopy, Electron, Scanning ; Rabbits ; Uvea/pathology/ultrastructure