Doctors, researchers, and clinical studies have evaluated how tear osmolarity is impacted by a variety of conditions in vivo, in vitro, and in animal models. The conclusions show that tear osmolarity is an integral factor in the complex condition of ocular surface disease.
In 1978 Jeff Gilbard, MD, a pioneer in ocular surface disease (OSD), proposed that hypersmolarity of the tear film plays an important role in inducing the disease seen in the cornea and conjunctiva.1 In 1979, Dr. Gilbard demonstrated that there was a significant positive correlation between tear film osmolarity and Rose Bengal staining.2
In rabbit models, he showed that decreases in corneal epithelial glycogen and in conjunctival goblet cell density, and morphological abnormalities of the conjunctiva correlated with increases in tear film osmolarity and duration of disease (1988).3 Dr. Gilbard also showed that closure of the meibomian gland orifices increased tear film osmolarity in the presence of normal lacrimal gland function and caused dry eye-type ocular surface abnormalities (1989).4
This work contributed to the International Dry Eye WorkShop in 2007, identifying tear hyperosmolarity as an important factor in the pathogenesis of DES including it as a part of the definition of dry eye.5
Dr. Mastrota is center director of Omni Eye Surgery in New York City and associate optometric editor of Optometry Times.Now, 35 years later, what do tear osmolarity studies show? Searching the literature, here’s what we find:
These studies evaluate how tear osmolarity is impacted by a variety of conditions in vivo, in vitro, and in animal models. It appears tear osmolarity is an integral factor in the complex condition of ocular surface disease.ODT
Gilbard JP, Farris RL. Tear osmolarity and ocular surface disease in keratoconjunctivitis sicca. Arch Ophthalmol. 1979 Sep;97(9):1642-1646.
Gilbard JP, Rossi SR, Gray KL, Hanninen LA, Kenyon KR. Tear film osmolarity and ocular surface disease in two rabbit models for keratoconjunctivitis sicca. Invest Ophthalmol Vis Sci. 1988 Mar;29(3):374-378.
Lemp MA, Baudouin C, Baum J, et al. The definition and classification of dry eye disease: Report of the definition and classification subcommittee of the International Dry Eye WorkShop (2007). Ocular Surface. 2007;5(2):75–92.
Torricelli AA, Novaes P, Matsuda M, Braga A, Saldiva PH, Alves MR, Monteiro ML. Correlation between signs and symptoms of ocular surface dysfunction and tear osmolarity with ambient levels of air pollution in a large metropolitan area. Cornea. 2013 Apr;32(4):e11-5. doi: 10.1097/ICO.0b013e31825e845d.
Clouzeau C, Godefroy D, Riancho L, Rostène W, Baudouin C, Brignole-Baudouin F. Hyperosmolarity potentiates toxic effects of benzalkonium chloride on conjunctival epithelial cells in vitro. Mol Vis. 2012;18:851-863. Epub 2012 Apr 6.
Fortes MB, Diment BC, Di Felice U, Gunn AE, Kendall JL, Esmaeelpour M, Walsh NP. Tear fluid osmolarity as a potential marker of hydration status. Med Sci Sports Exerc. 2011 Aug;43(8):1590-1597. doi: 10.1249/MSS. 0b013e31820e7cb6.