Grand Rounds Answers

             CASE #2

        This patient was wearing a popular silicone hydrogel lens, with the highest amount of oxygen transmission on the market. Unfortunately, when oxygen transmission is measured, it is usually the value for the centre of the lens that is publicized, not the periphery. Due to the eyelid anatomy of this patient, much of her cornea was covered by her lids. When this patient was switched to a different silicone hydrogel lens with less central oxygen transmissibility but more on the periphery, she was actually more comfortable and the blood vessels receeded.