Changes in the Corneal Endothelium of Aphakic Patients Following Extended Soft Contact Lens Wear
The contact lenses used for visual correction of aphakia are mostly soft contact lenses for extended wear because most aphakic patients are elderly. The effects of extended wear of such contact lenses on corneal endothelial cells have been recently reported. In this study, two groups, an extended wear SCL group and a spectacles group, were compared with respect to various parameters by means of specular microscopy following surgery for cataract. The SCL group consisted of 16 subjects and 16 eyes. The average age at operation was 67.8 years and the wearing period was 1 to 5 years after operation. The spectacles group consisted of 14 subjects and 16 eyes; the average age at operation was 70.1 years, and the wearing period was 1 to 5 years after surgery. Using a wide field specular microscope (mode1 SP-1), endothelial cells in the central part of the cornea were observed and photographed. The endothelial cell picture was then enlarged to a final magnification of 450 times, and the image was analyzed using the KC-8VA cell analyzer system. There was no significant difference in the mean cell area (μm2) and mean cell density (cell counts/mm2) between the two groups, but the coefficient of variation (CV) was significantly elevated in the SCL group after operation. The percentage of hexagonal cells was also significantly lower in the SCL group after operation. Therefore extended wear of soft contact lenses appears to make corneal endothelial cells unstable and accelerates changes in cornet endothelial cells due to aging.