Ocular surface injuries in autoimmune dry eye. The severity of microscopical disturbances goes parallel with the severity of symptoms of dryness
J. Čejková1, T. Ardan1, Č. Čejka1,2, J. Malec2, K. Jirsová3, M. Filipec3, E. Růžičková3, D. Dotřelová2 and B. Brůnová2
1Department of Eye Histochemistry and Pharmacology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic, 2Department of Ophthalmology for Children and Adults, Motol Hospital, Charles University, 2nd Medical School, Prague, Czech Republic and 3Eye Clinic and Laboratory of the Biology and Pathology of the Eye, Institute of Inherited Metabolic Disorders, General Teaching Hospital and Charles University, Prague, Czech Republic.
Offprint requests to: Prof. Jitka Cˇejková, MD, PhD, DSc, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Vídenˇská 1083, 14220, Prague 4, CR. e-mail: cejkova@biomed.cas.cz
Summary. Autoimmune dry eye (Sjögren’s syndrome, SS) is a chronic systemic disease characterized by salivary and lacrimal gland inflammation and tissue damage leading to keratoconjunctivitis sicca and xerostomia. In this review attention has been devoted to the cause of the development of oxidative injuries of the ocular surface of patients suffering from SS. It was shown that lacrimal glands and diseased conjunctival epithelium reveal increased expression of pro-inflammatory cytokines which are released into the tear fluid. A high amount of pro-inflammatory cytokines highly induce the elevated expression and activity of enzymatic systems that generate reactive oxygen and nitrogen species. An abundant amount of these toxic products leads to a decrease in antioxidants and to the formation of cytotoxic related oxidants, such as peroxynitrite. All these factors, together with reactive oxygen species from polymorphonuclear leukocytes, contribute to the development of oxidative injuries at the ocular surface. From the clinical point of view it is important that the level of severity of the above described microscopical disturbances found in conjunctival epithelial cells goes parallel with the level of severity of dry eye symptoms. Histol Histopathol 24, 1357-1365 (2009)
Key words: Autoimmune dry eye, Oxidative injuries, Pro-inflammatory cytokines, Reactive oxygen and nitrogen species, Antioxidant enzymes
DOI: 10.14670/HH-24.1357