Fibronectin concentration in tears of contact lens wearers.

The tears of soft contact lens wearers (wearing lenses on an extended were schedule) were analysed for the amount of fibronectin, albumin and total protein. Tears were collected during the day without stimulation and the levels were then compared to levels in non-contact lens wearers tears. The level of fibronectin in the tears of contact lens wearers (120 ng ml-1) was significantly higher than in the tears of non-contact lens wearers (21 ng ml-1; P < 0.01). There were no differences in the amount of albumin or total protein. When contact lens wearers were divided into those subjects who carried significant levels of bacteria on their contact lenses and non-carriers, the amount of fibronectin and albumin was found to be higher in the tears of bacterial carriers (P < 0.03), whereas the amount of total protein remained the same. The fibronectin in the tears and on the contact lens may predispose subjects to contamination by bacteria and thus increase the risk of inflammatory or infectious diseases associated with bacterial contamination of contact lenses.