Horwitz B L, Christensen G R, Ritzmann S R
Ann Ophthalmol. 1978 Jan;10(1):75-80.
Tear lysozyme and gamma A globulin (IgA) concentrations were determined during a 24 hour period using a simple quantitative method. Tear lysozyme was significantly elevated between the 9 and 12 AM periods, and reduced during the sleep periods from midnight to 3 AM. Tear IgA concentrations showed individual variability, but no discernible diurnal rhythm.