Immunopathogenesis of Conjunctival Histopathologic Alteration in Non-Sjögren’s Keratoconjunctivitis Sicca

Abstract

Dry eye or keratoconjunctivitis sicca (KCS) is a common ocular surface disease characterized by quantitative or qualitative abnormality of the tear film, ocular surface damage and ocular discomfort. It is a major health problem affecting millions of people worldwide: 11% 30 to 60 years old and 14.6% over 65 (4.3 million). Pflugfelder et al. have shown elevation of mRNA levels of inflammatory cytokines such as IL-la, IL-6, IL-8 and TNF-a in conjunctival cytology specimens of Sjögren’s syndrome with KCS (SSKCS). These findings suggest that the inflammatory response plays a role in pathogenesis of SS-KCS. Recent evidence suggests the inflammatory response may also play a role in pathogenesis of non-SS-related KCS (NS-KCS) that affects most patients with dry eye. The conjunctival inflammatory status of NS-KCS has not been well studied. To investigate the role of inflammation in the pathogenesis of NS-KCS, we examined the expression of inflammatory cytokines in conjunctival biopsies from patients with NS-KCS and asymptomatic controls.