Hydrogen ion concentration of tear fluid in newborn infants.
Tear pH was measured in 173 newborn infants by immersing the tip of a microcombination glass pH probe in the tear fluid lateral in the closed lower conjunctival sac. The median tear pH value was 6.8 with 95% interpercentile range 6.2 to 7.2. The mean tear pH value was 6.74 +/- 0.26 (SD). The pH value was not related to age within the first 12 days and not influenced by the mode of delivery or local application of 0.67% argenti nitratis. This method is an easy, reliable examination to record the pH values of tear fluid, and may widen the knowledge of tear function in normal and pathological conditions.
D005260:Female; D005865:Gestational Age; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D008297:Male; D013666:Tears / Q000032:analysis*