Morphologic effects of contact lens wear on the corneal surface

We used specular microscopy of the corneal epithelium to examine 29 eyes of 29 patients each wearing one of five different types of contact lenses. We compared these with 24 eyes of 24 age-matched control patients. We found patients with aphakic extended wear soft contact lenses had significantly larger cells (818 ± 186 μm²) than all other groups; and they were significantly larger than their age-matched control group (573 ± 174 μm²)(P <.002). The epithelial cells of extended wear soft contact lens patients (609 ± 97 μm²) and daily wear rigid gas permeable contact lens patients (613 ± 103 μm²) were larger than their control group of normal young patients (513 ± 53 μm²). The cells of daily wear soft contact lens patients (484 ± 111 μm²) and hard contact lens patients (517 ± 46 μm²), however, were not different from controls. This study domonstrates a statistically significant shift in mean cell area of corneal epithelial cells in patients wearing some types of contact lenses.