Related Experiment Video
Updated: May 6, 2026
Bead Based Multiplex Assay for Analysis of Tear Cytokine Profiles
Published on: October 13, 2017
Preliminary identification of differentially expressed tear proteins in keratoconus
Sivaraman A Balasubramanian1, Valerie C Wasinger, David C Pye
1School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia ; School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia ; Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia.
Purpose:
To examine the proteins differentially expressed in the tear film of people with keratoconus and normal subjects.
Methods:
Unstimulated tears from people with keratoconus (KC) and controls (C) were collected using a capillary tube. Tear proteins from people with KC and controls were partitioned using a novel in-solution electrophoresis, Microflow 10 (ProteomeSep), and analyzed using linear ion trap quadrupole fourier transform mass spectrometry. Spectral counting was used to quantify the individual tear proteins.
Results:
Elevated levels of cathepsin B (threefold) were evident in the tears of people with KC. Polymeric immunoglobulin receptor (ninefold), fibrinogen alpha chain (eightfold), cystatin S (twofold), and cystatin SN (twofold) were reduced in tears from people with KC. Keratin type-1 cytoskeletal-14 and keratin type-2 cytoskeletal-5 were present only in the tears of people with KC.
Conclusions:
The protein changes in tears, that is, the decrease in protease inhibitors and increase in proteases, found in the present and other previously published studies reflect the pathological events involved in KC corneas. Further investigations into tear proteins may help elucidate the underlying molecular mechanisms of KC, which could result in better treatment options.
