Morphological and cytokine profiles as key parameters to distinguish between Gram-negative and Gram-positive bacterial keratitis

Abstract

Bacterial keratitis (BK) is an ocular disorder associated with poor visual prognosis. Quantification of the associated inflammatory response may provide insight into the pathogenesis of BK and guide treatment options. In this exploratory study, we evaluated 45 BK patients and 20 healthy controls by optical coherence tomography and pro-inflammatory tear cytokine analysis. The aim was to quantify the differential morphological and cytokine inflammatory response between Gram-negative and Gram-positive BK and to determine the diagnostic value of corneal thickness (CT) and infiltrate thickness (IT) in distinguishing Gram−ve BK in a clinical cohort. Greater CT and IT, at clinical presentation, were indicative of Gram−ve infection with values detected of ≥ 950 μm and ≥ 450 μm, respectively. Combination of these CT and IT values had a 100% sensitivity and 83.3% specificity as a diagnostic indicator of Gram−ve infection. Similarly, there were higher levels of IL-1β, IL-6 and IL-8 cytokines were quantified in keratitis caused by Gram-negative bacteria. Among the different tear cytokines analysed, a significant reduction after three days of treatment was detected for pro-inflammatory cytokines IL-1β, IL-2, IL-6, IL-8 and TNF-α, prior to starting with the administration of steroid drops. Overall, this study shows the potential value of serial OCT and tear cytokine measurements in the management of BK.

ROS-scavenging glyco-nanoplatform for synergistic antibacterial and wound-healing therapy of bacterial keratitis

“…IL-1b and TNF-a are two critical pro-inflammatory factors in the etiopathogenesis of microbial keratitis. [34][35][36][37] The antiinflammatory effect of the drug-loaded nanoparticles was assessed by ELISA kits. On day 5 after administration, the rats were executed and the corneas were excised (n = 5).…”

Comparison study between Pilocarpine and Tropicamide drops on corneal topography and their effect on IL-6 and TNF-α levels in tear

“…Several animal models have studied the immunological mechanisms of ocular damage in MK (18,19). Studies on human epithelial-derived cells and gram-negative bacteria have suggested that IL-6, IL-8, and tumor necrosis factor (TNF)-α in tear are cytokines involved in immune-induced corneal damage (20,21).…”