Dry Eye Disease and Microbial Keratitis: Is There a Connection?

Abstract

Dry eye is a common ocular surface disease of multifactorial etiology characterized by elevated tear osmolality and inflammation leading to a disrupted ocular surface. The latter is a risk factor for ocular surface infection, yet overt infection is not commonly seen clinically in the typical dry eye patient. This suggests that important innate mechanisms operate to protect the dry eye from invading pathogens. This article reviews the current literature on epidemiology of ocular surface infection in dry eye patients and laboratory-based studies on innate immune mechanisms operating at the ocular surface and their alterations in human dry eye and animal models. The review highlights current understanding of innate immunity in dry eye and identifies gaps in our knowledge to help direct future studies to further unravel the complexities of dry eye disease and its sequelae.

To assess the prevalence of dry eye disease in postmenopausal females in a tertiary care centre in Central India

“…In our study, prevalence of dry eye was maximum in age group greater than 74 years (38.46%) and we also found that prevalence increases progressively with age. These results were consistent with study done by Anshu Sahai et al (2005) [18] Ram S Mirley (2000) suggested that both tear flow rate and tear stability reduces with age and by the age of 40 years, tear production is reduced to 50% of that at the age of 10 years. Reduction of tear volume and flow and increase in evaporation have been noted in elderly as seen in study of Mathers et al(1996) [20] .In another study of dry eye syndrome among US women showed that the prevalence of DES increased with age, from 5.7% among women < 50 years old to 9.8% among women aged ≥ 75 years old.…”

Impact of Microbiome on Ocular Health

“…11 Promisingly, the expanding applicability of deep sequencing approaches will provide us with insights to whether alterations of the ocular surface microbiota correlate with the development of dry eye disease. 36 …”

Corticosteroids and Anti-Complement Therapy in Retinal Diseases

“…4 Lipiview is a new diagnostic tool that uses dynamic infrared transillumination to visualize structural changes suggesting meibomian gland dilation, atrophy, or dropout. Images (a) and (b) demonstrate a visible contrast between normal gland structure and gland dropout, and a dramatic difference in lipid layer thickness (LLT) decreased concentration of mucin, the resultant accumulation of inflammatory factors can penetrate tight junctions and cause epithelial cell death (Narayanan et al 2013).…”

“…For example, the antimicrobial peptides of the innate immune system lose their ability to kill Pseudomonas aeruginosa in the presence of carboxymethyl cellulose solutions in vitro. Cyclosporine has been found, in vitro, to inhibit the production of cytokines involved in wound healing, and increase susceptibility of epithelial cells to viral infection by reducing interleukin production; in human corneal epithelial cells, it has been shown to inhibit cell proliferation (Narayanan et al 2013). Despite the potential drawbacks these agents remain the mainstay of treating DED.…”

“…While these are valuable and proven tools for mild to moderate DED, more severe disease that is resistant to treatment may merit antibiotic therapy. Oral tetracyclines are commonly used to treat DED given their dual impact of broad spectrum antibacterial prophylaxis (though only minocycline and doxycycline are able to reach an effective concentration on the ocular surface), and anti-inflammatory effect, achieved through reduction of MMPs, IL-1α and TNF-α (Narayanan et al 2013). A new approach to treatment of MGD is LipiFlow, in-office thermodynamic treatment for obstructed meibomian glands.…”