Figure 2. Tear secreted frizzled-related protein 1 (SFRP1) and ratio of SFRP1/total tear protein were significantly lower in age matched KC, compared to control patients. A: Tear SFRP1 concentration was significantly lower in age-matched KC than controls. B: Total tear-protein concentration in age-matched KC was significantly higher than controls. C: Ratio of SFRP1/ total tear protein was significantly lower in age-matched KC compared to controls. Error bar: standard deviation.