Fibronectin in tears following surgical trauma to the eye

The concentration of the high molecular glycoprotein fibronectin (FN) was measured by an enzyme-linked immunoadsorbent technique (ELISA) in tears of 25 patients before and after cataract extraction. Both native and degraded FN was measured. The median concentration of FN in tears before surgery was 0.28 mg/l (range: 0.1-3.8 mg/l) and 0.18 mg/l (range: 0.1-1.95 mg/l for degraded and native FN, respectively. The time course of the median values of both types of FN during the post-operative observation period described a biphasic curve with peaks at the second and fifth day following operation. On the twelfth day the concentration of degraded and native FN had almost reached pre-operative levels. The variation in the post-operative FN concentration proved statistically significant. The biological significance of the changes in FN level in the post-operative period is not obvious; the first peak may be explained by a spill-over from plasma, and the second peak may reflect FN production from fibroblasts in the granulation tissue of the corneoscleral cicatrix.