Corneal response to extended wear of CAB contact lenses in aphakia.

We studied 41 aphakic eyes in 30 patients who had been wearing CAB (cellulose acetate butyrate) contact lenses on an extended basis. Patients were 51 to 81 years old and averaged 14.3 months of wearing time. Visual acuity was very good. Pachometry measurements ranged from 0.42 mm to 0.66 mm and averaged 0.550 mm. This compares favorably with data in the literature on corneal thickness seen with routine use of PMMA or hydrogel lenses or with extended wear of hydrogel lenses. Corneal thickness was also compared with unoperated fellow eyes and eyes using CAB lenses on a daily basis only.