Development of a new soft gas permeable contact lens with Dk 300

The effects on the rabbit cornea of a new gas permeable nonhydrophilic soft contact lens made of newly designed polymer with a Dk value of 300 were studied physiologically, histologically, and histochemically during 5 days of daily wear followed by 14 days of extended wear. Corneal swelling was observed to be within 10% of corneal thickness during the wear period. No serious corneal surface changes were observed. Specular microscopy showed no endothelial changes in terms of cell density, coefficient of variation of cell area (CV), or hexagonality before and 2 weeks after lens wear. Histochemical study using periodic acid-Schiff staining and histological study with hematoxylin-eosin revealed no remarkable changes. Scanning electron microscopy revealed slight focal changes; there were no significant changes. The results show that the new soft gas permeable contact lens has no harmful effect on the rabbit cornea.