Microscopically and chemically detected haemolacria.

Two methods have been developed for the detection of occult haemolacria (occult blood in tears): 1) Microscopy of conjunctival fluid aspirated by means of the quantitative pipette method. 2) Chemical stix method employed on a sample of conjunctival fluid transferred to cotton-wool plug. Double samples from 306 eyes were subjected to microscopy, and chemical tests were performed on samples from303 other eyes. Microscopy has been found to disclose occult blood in 13 per cent of normals (greater than or equal to 100 erythrocytes/3.1 mm2 in 3 per cent of normals), while blood is detected chemically in 3 percent. Occult blood is most frequently found in cases of acute infectious conjunctivitis (65 per cent microscopically and 21 per cent chemically), less frequently in subacute and chronic infectious conjunctivitis (26 and 20 per cent respectively). Haemolacria is most feequently seen in relation to neutrophilia (45 per cent), less frequently with lymphocytosis (35 per cent), and even more rarely in the absence of both neutrophilia and lymphocytosis (11 per cent). Ciliary congestion is an unlikely cause of haemolacria. Postoperatively blood is present for two or three days, wheras blood instilled into the conjunctival sac of a normal eye disappears in less than one hour. The protein concentration in tears is raised in association with haemolacria.