Participants
Inclusion criteria for the experimental group: clinical diagnosis was concomitant exotropia, refractive errors(spherical≤±1.00D,anastigmate or cylindrical≤0.50)were corrected by wearing glasses, and there were no neurological diseases or craniofacial abnormalities. Except for strabismus and refractive errors, the patients had no history of other visual defects and eye diseases, and no family genetic history (including history of strabismus). Inclusion criteria for the control group:refractive errors(spherical≤±1.00D,anastigmate or cylindrical≤0.50)were corrected by wearing glasses, no neurological disease, no craniofacial abnormalities, no history of visual impairment or eye disease, and no family history of hereditary diseases (including strabismus). No related symptoms such as dry eyes. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the Ethics Committee of The First Affiliated Hospital of Fujian Medical University. Informed consent was obtained from legal guardians.
Tears collection
We use tears adsorption filter paper (Tianjin Jingming New Technology Development Co., LTD., Tianjin; China Strip (Hereinafter referred to as China Strip) ) to collect tears from the subjects. Schirmer. The tears samples were eluted with 200uL PBS and shaken for 5 hour at room temperature, then the samples were stored in a refrigerator at -80℃[5].
Measurement of inflammatory cytokines
For SIMOA experimental tears samples were prepared according to the kit specfic manufacturers instruction. The levels of inflammatory cytokines were measured using a SIMOA HD-X Cytokine 6-Plex Panel Standards and samples were run utilizing the manufactures assay instructions. The lower limits of quantification (LLOQ) for IL-10, INF-γ, IL-12p70, TNF-α, IL-17A, IL-6 were 0.0660 pg/mL, 0.0710 pg/mL, 0.0290 pg/mL, 0.1270 pg/ml , 0.0320 pg/mL , and 0.1320 pg/mL respectively in the panel 1.The LLOQ for IL-10, INF-γ, IL-12p70, TNF-α, IL-17A, IL-6 were 0.0142 pg/mL, 0.0052 pg/mL, 0.0031pg/mL, 0.0283 pg/ml , 0.0032 pg/mL , and 0.0221 pg/mL respectively in the panel 2. The limit of detection (LOD) for IL-10, INF-γ, IL-12p70, TNF-α, IL-17A, IL-6 were 0.0142 pg/mL, 0.0052 pg/mL, 0.0031 pg/mL, 0.0283 pg/ml, 0.0032pg/mL, and 0.0221pg/mL respectively in the panel 1, and the limit of detection (LOD) for IL-10, INF-γ, IL-12p70, TNF-α, IL-17A, IL-6 were 0.0144 pg/mL, 0.0033pg/mL, 0.0032 pg/mL, 0.0261 pg/ml, 0.0033pg/mL, and 0.0249pg/mL respectively in the panel 2, and concentration below LOD are used the LOD as the concentration of tear.
Statistical analyses
All of the date were analyzed with the SPSS 20.0 program (IBM Corp. SPSS Statistics for Windows, version 20.0, Armonk, NY, USA). All the results were statistically analyzed to compare the differences between groups, and P <0.05 was considered statistically significant.