A new rigid gas-permeable semi-scleral contact lens for treatment of corneal surface disorders.

Some extreme corneal irregularities cannot be treated adequately with corneal contact lenses. For such cases a rigid semi-scleral lens can be prescribed. We evaluated the use of a highly gas permeable rigid semi scleral lens in patients with diseased corneas for whom conventional contact lens strategies had failed. Twenty two patients (29 eyes) were successfully fitted with individually manufactured semiscleral lenses. Corneal hypoxia, which has previously limited the use of polymethylmethacrylate (PMMA) scleral contact lenses, did not occur. The semi scleral lenses were well tolerated. Two cases were selected to illustrate the fitting of these lenses.