Tear production in vitamin A-responsive xerophthalmia.

Schirmer tests showed decreased tearing (less than 15 mm of wetting) in 32 of 54 eyes (59%) of a representative group of patients with corneal xerophthalmia but in only four of 60 eyes (7%) of age-, sex-, and neighborhood-matched controls (P less than .001). The occurrence of decreased tearing was directly related to protein status: eight of 18 eyes (44%) of children with serum transferrin levels below 50 mg/100 ml but only 13 of 62 eyes (21%) of children with higher levels produced less than 15 mm of wetting (P less than .01). Among otherwise well-nourished children, the occurrence of decreased tearing was directly related to the severity of xerophthalmia and thus to vitamin A status. We found decreased tearing in eight of 86 eyes (9%) of a group of unpaired controls, in nine of 38 eyes (24%) of children with conjunctival xerosis, and in 17 of 62 eyes (27%) of children with corneal involvement (P less than .01).