Subjects and tear collection
The research followed the Tenets of the Declaration of Helsinki. Institutional Review Board approval was obtained. Written informed consent was obtained from all subjects or, in the case of minors, from their parents after explanation of the nature and the possible consequences of the study. Eleven normal control subjects (CTRL) (5 females, 6 males; mean age 19+5.3; range 7-30), 23 active VKC patients (mean age 15+10.4; range 5-40) and 7 active AKC patients (mean age 16+4.1; range 8-20) were included in the study (supplementary Table 1). All patients and CTRL were free of medication for at least 5 days before sample collection. Tears were collected gently from the external canthus in the morning between 9am and 11am using a glass capillary tube. Tear samples were centrifuged, supernatants were collected and immediately frozen at -80°C before analyzed. Samples were not pooled from both eyes or from different patients.