To review the advances in the diagnosis, pathogenesis, and management of dry eye disease in the past 25 years. Literature review. The preocular tear film is a hydrated mucus gel that contains soluble antimicrobial proteins and growth factors that protect and support the ocular surface. The final common pathway in dry eye is a perturbation of the integrated ocular surface/lacrimal gland reflex unit. Diagnostic tests evaluating tear composition and clearance appear to show stronger correlation with the severity of ocular irritation symptoms and keratoconjunctivitis sicca (KCS) than the conventional Schirmer tests. KCS is a condition of abnormal differentiation and mucus production by the ocular surface epithelium that results in a poorly lubricated, abnormally permeable ocular surface that has increased susceptibility to environmental insults. Chronic subclinical ocular surface inflammation appears to play a key role in the pathogenesis of KCS. New therapeutic strategies are aimed at reducing the ocular surface inflammation of dry eye disease. There has been a tremendous increase in knowledge regarding dry eye disease in the past 25 years that has resulted in improved diagnostic classification and new targeted therapies.

AIMS Amniotic membrane (AM) transplantation reduces inflammation in a variety of ocular surface disorders. The aim of this study was to determine if AM stroma suppresses the expression of the IL-1 gene family in cultured human corneal limbal epithelial cells. METHODS Human corneal limbal epithelial cells were cultured from limbocorneal explants of donor eyes on plastic or on the AM stroma. Transcript expression of IL-1α, IL-1β, IL-1 receptor antagonist (RA), and GAPDH was compared with or without addition of lipopolysaccharide to their serum-free media for 24 hours using RNAse protection assay (RPA). Their protein production in the supernatant was analysed by ELISA. RESULTS Expression of IL-1α and IL-1β transcripts and proteins was significantly reduced by cells cultured on the AM stromal matrix compared with plastic cultures whether lipopolysaccharide was added or not. Moreover, expression of IL-1 RA by cells cultured in the lipopolysaccharide-free medium was upregulated by AM stromal matrix. The ratio between IL-1 RA and IL-1α protein levels in AM cultures was higher than in plastic cultures. CONCLUSIONS AM stromal matrix markedly suppresses lipopolysaccharide induced upregulation of both IL-1α and IL-1β. These data may explain in part the effect of AM transplantation in reducing ocular surface inflammation, underscoring the unique feature of the AM as a substrate for tissue engineering.