Life on implants

Seven Ridley Mark I anterior chamber lenses were removed from patients at St Thomas's Hospital. The lenses had been in place for an average of 15 years. The indication for removal was corneal endothelial decompensation with painful bullous keratopathy. Examination of the lenses under the scanning electron microscope showed remarkably similar morphology in each case. A well organised fibrin membrane covered the implants to which iris pigment epithelial cells were adherent. Red blood cells, scattered fibroblasts and pigment granules were also found. Giant cells were not identified while macrophages and lymphocytes were rare. These findings suggest that corneal endothelial decompensation was not due to chronic inflammation but was probably caused by movement of the implants within the eyes.