ABSTRACT Forty‐six patients who were unable to wear polymethylmethacrylate (PMMA) contact lenses, owing mainly to corneal edema and associated symptoms, were fitted with gas‐permeable hard Polycon® lenses of the same dimensions. Thirty‐one patients (67%) wore the POLYCON lenses successfully. Thirteen (28%) did not, because of discomfort. For 2 patients, the results were unknown. None of the 46 patients exhibited observable edema with the POLYCON lenses. For a group of 5 patients (10 eyes), mean corneal thickness change after 8 hr of lens wear was insignificant. Oxygen transmissibility of these lenses is approximately 5.0 × 10 ‐11 (cm 2 × ml O 2 )/(sec × ml × mm Hg), a value less than that for hydrogel lenses which produce more edema. It is predicted that gas‐permeable hard lenses will eventually replace PMMA lenses.
Sarver et al. (Fri,) studied this question.