Biochemistry (Moscow)

, Volume 73, Issue 4, pp 381–392

Tear proteins in health, disease, and contact lens wear


DOI: 10.1134/S0006297908040020

Cite this article as:
Sariri, R. & Ghafoori, H. Biochemistry Moscow (2008) 73: 381. doi:10.1134/S0006297908040020


Although well known as manifestations of sorrow, emotions, frustration, and blackmail, tears have a more prosaic and important function as a lubricant and as a blood substitute for the cornea. Tears transport oxygen and carbon dioxide and play a central role in the cellular economy of the ocular surface and conjunctiva. In addition to proteins, tears contain lipids and glycoproteins, which increase the wetting effect of the aqueous component and delay evaporation. The total protein concentration of tears is about 10% of that of the plasma. About 80 proteins and polypeptide components have been detected by electrophoresis. Among 30 proteins identified in tears, about 50% are enzymes. Some of the tear enzymes are secreted by the lacrimal glands; others are produced by or released from epithelial cells of the cornea and the conjunctiva. Finally, a few enzymes originate from plasma and appear in tears only in cases with increased permeability of the conjunctival vessels. The aim of this review is to provide clinical and biochemical information about tear enzymes both for ophthalmologists and for biochemists interested in clinical and experimental tear enzymology.

Key words

tear enzymes lysozyme lactoferrin tear specific pre-albumin contact lenses eye disorders 



creatine kinase


herpes simplex virus


lactate dehydrogenase


malate dehydrogenase


plasminogen activator


plasminogen activator inhibitor


pyruvate kinase

Copyright information

© MAIK Nauka 2008

Authors and Affiliations

  1. 1.Department of Biochemistry, Faculty of ScienceUniversity of GuilanRashtIran

Personalised recommendations