Effect of Soft Lens Power on Peripheral Corneal Edema

The effect of soft lens design (lathe cut, spun cast) and power (‐0.75 to −9.00 D) on central and peripheral corneal swelling was analyzed by measuring the change in corneal thickness after 3 h of eye closure and at mid‐day during extended wear. Peripheral swelling was less than central for both lathe cut‐ and spun cast‐type lenses. Significant correlations were found between spun cast lens power and central (r = +0.48) or peripheral (r = +0.32) swelling during eye closure. Small differences in swelling occurred with different power lathe cut lenses (r = −0.19). Correlations of mid‐day (open eye) central corneal swelling with lens power were significant for both the spun cast (r = +0.43) and lathe cut (r = −0.53) lenses. However, correlation of peripheral swelling with power was weak. These results indicate that significant lateral diffusion of oxygen and/ or epithelial metabolites may be occurring in the cornea between areas of high and low oxygen tension.