Nitric oxide levels in tears of patients with mild forms of papillary conjunctivitis induced by rigid gas-permeable contact lenses

To determine whether nitric oxide (NO) is detectable in the tear fluid of patients with mild forms of papillary conjunctivitis who wear rigid gas-permeable contact lenses. Tear samples were taken from 12 users of rigid gas-permeable contact lenses and 12 healthy controls. Samples were analyzed, and the levels of NO were determined. The mean level of NO in those who wore contact lenses was 118.98 micromol/L (95% CI: 91.85-146.10 micromol/L); whereas the level of NO found in the control subjects was 114.84 micromol/L (95% CI: 102.54-127.14 micromol/L). The difference was statistically insignificant (P>0.05). Nitric oxide levels in the tear fluid of rigid gas-permeable contact lens users did not correlate with the presence of mild symptoms of papillary conjunctivitis.