RESUMO
PURPOSE: The purpose of this study was to compare the lactate dehydrogenase (LDH) activities in the tears of patients wearing different types of contact lenses with each other and to individuals who have never worn contact lenses (controls). METHODS: Tear LDH activities were determined in 13 normal subjects who had never worn contact lenses, 12 daily wear and ten extended wear soft contact lens wearers, and 14 daily wear and eight extended wear rigid gas permeable (RGP) contact lens wearers(Dk125). Tear samples were collected from all subjects at the same time of day from the inferior meniscus by using a microcapillary tube. The measurements were determined using a Sigma diagnostic LDH reagent and a spectrophotometer. RESULTS: There was no statistically significant difference in the LDH activities between soft and RGP contact lenses--used either as daily or extended wear--when compared with each other. However, individuals wearing extended wear soft contact lenses had significantly higher tear LDH activities than the control group. CONCLUSION: Tear LDH activity may be a useful method in evaluating the physiologic response of extended soft contact lens wear.
