Abstract
Abstract: :
Purpose:Vascular endothelial growth factor (VEGF) is a proangiogenic mediator that is stimulated in response to hypoxia and inflammation. Peripheral, corneal neovascularization, or pannus, has been associated with soft contact lens (SCL) use. This study examined tear VEGF concentrations as a function of SCL wear time to assess whether chronic use is associated with elevated levels of VEGF. Methods:With a microcapillary tube, tear samples were collected from the inferior fornix of a control group (non–SCL users), occasional SCL users (1–3 days/week, 6 hours/day), and chronic SCL users (daily, >12 hours/day. Sampling was performed at 10 hours after instillation of SCL, and at the same time point in the control group. Tear VEGF levels were measured using a commercially available enzyme linked immunoassay in accordance with the manufacturer’s recommendations. Results:Mean tear VEGF levels in the control group were 307 pg/ml. After 10 hours of SCL use, tear VEGF levels were elevated in the chronic SCL user group (mean: 636 pg/ml) as compared with the occasional SCL users (mean: 383 pg/ml). Conclusions:Daily, extended use of SCL appears to be associated with increased in tear VEGF levels as compared with occasional SCL use.
Keywords: cornea: tears/tear film/dry eye • contact lens • cornea: clinical science