Dear Prafulkumar,

You may follow the method described by Romanto V. & Coworkers in a publication entitled "TNF-Alpha Levels in Tears: A Novel Biomarker to Assess the Degree of Diabetic Retinopathy " published in Mediators Inflamm. 2013; 2013: 629529.

Patients and Methods

Nonstimulated tears were collected from each eye from the inferior tear meniscus between the 6 o'clock and lateral canthus positions using a standard clinical Schirmer's strip. Following collection, the strip was immediately transferred into a sterile labelled tube and frozen at −40°C until analysed. The wet portion of each Schirmer's strip was then cut into smaller pieces and soaked in 50 μL/5 mm of phosphate-buffered saline (PBS) for 3 h to elute tear proteins. TNF-alpha was measured using a 96-well plate coated with antibody specific for human TNF-alpha, according to manufacturer's instructions (Human TNF-alpha ELISA Development Kit PEP-900-K25, Li StarFish S.r.l.Cernusco S/N, Milan, Italy).

Data were recorded in an Excel 2007 spreadsheet and analyzed by SPSS statistical software. For analysis of statistical differences, we used the Wilcoxon signed-rank test to evaluate the intragroup significance between variables. Conversely, the Mann-Whitney U-test was used to compare the control and DR groups. A P value of  

Dear Rafik

Thank you