Studies of residual alkali on intraocular lenses sterilized with NaOH

We measured the effects of pH changes after water washings of polymethylmethacrylate (PMMA) intraocular lenses sterilized in 10% sodium hydroxide (NaOH). Whereas inserting the base-sterilized lens directly into the eye causes a large pH change in the local area of the implant, three separate washings of the NaOH-treated implant in 15 ml of water eliminates this change. No buffer is required.