Dry eye disease can be a consequence of lacrimal gland insufficiency in Sjögren’s Syndrome or increased tear film evaporation despite normal lacrimal gland function. To determine if there is a correlation between severity effects in these models and underlying pathophysiological responses, we compared the time dependent changes in each of these parameters that occur during a 6 week period. Dry eye was induced in 6-week-old female C57BL/6 mice by exposing them to an Intelligently Controlled Environmental System (ICES). Sixty mice were housed in ICES for 1, 2, 4 and 6 weeks respectively. Twelve were raised in normal environment and received subcutaneous injections of scopolamine hydrobromide (SCOP) 3 times daily for 5 days. Another sixty mice were housed in a normal environment and received no treatment. Corneal fluorescein staining along with corneal MMP-9 and caspase-3 level measurements were performed in parallel with the TUNEL assay. Interleukin-17(IL-17), IL-23, IL-6, IL-1, TNF-α, IFN-γ and TGF-β2 levels were estimated by real-time PCR measurements of conjunctival and lacrimal gland samples (LGs). Immunohistochemistry of excised LGs along with flow cytometry in cervical lymph nodes evaluated immune cell infiltration. Light and transmission electron microscopy studies evaluated LGs cytoarchitectural changes. ICES induced corneal epithelial destruction and apoptosis peaked at 2 weeks and kept stable in the following 4 weeks. In the ICES group, lacrimal gland proinflammatory cytokine level increases were much lower than those in the SCOP group. In accord with the lower proinflammatory cytokine levels, in the ICES group, lacrimal gland cytosolic vesicular density and size exceeded that in the SCOP group. ICES and SCOP induced murine dry eye effects became progressively more severe over a two week period. Subsequently, the disease process stabilized for the next four weeks. ICES induced local effects in the ocular surface, but failed to elicit lacrimal gland inflammation and cytoarchitectural changes, which accounts for less dry eye severity in the ICES model than that in the SCOP model.

Purpose.: To compare the microstructural differences in fresh corneal tissue (FCT) with glycerin-cryopreserved corneal tissue (GCCT) used during deep anterior lamellar keratoplasty (DALK). Methods.: The medical records of 48 consecutive patients who underwent DALK for stromal opacity without endothelial abnormalities were retrospectively reviewed. Patients were divided into two groups: an FCT group (n = 22) and a GCCT group (n = 26), according to the corneal tissue used. The best corrected visual acuity (BCVA), slit lamp, corneal topography, pachymetry, and laser scanning in vivo confocal microscopy examinations at 2 weeks and 1, 3, 6, 12, and 24 months after surgery were analyzed. Results.: No graft rejection developed in the GCCT group, whereas stromal rejection developed in one eye in the FCT group. There were no significant differences in spherical equivalent (P = 0.37), astigmatism (P = 0.26), BCVA (P = 0.64), central corneal thickness (P = 0.73), or endothelial cell density (P = 0.49) between the two groups at 24 months. Confocal microscopy showed that GCCT was acellular, whereas dendritelike cells and keratocytes were found in the FCT group 2 weeks after surgery. The keratocyte density improved significantly in the GCCT group at 3 months after surgery, whereas it decreased significantly after surgery in the FCT group during follow-up. No significant difference in regeneration of nerve fibers was found in the subbasal layer and anterior stroma between the two groups at 24 months. Conclusions.: DALK using GCCT provides clinical results comparable to FCT. GCCT can be used safely and effectively for DALK and may minimize stromal rejection after surgery.

Purpose: Ocular surface microbiome changes can affect meibomian gland dysfunction (MGD) development. This study aimed to delineate differences among the microbiome of eyelid skin, conjunctiva, and meibum in healthy controls (HCs) and patients afflicted with MGD. Methods: Shotgun metagenomic analysis was used to determine if there are differences between the microbial communities in ocular sites surrounding the meibomian gland in healthy individuals and patients afflicted with MGD. Results: The meibum bacterial content of these microbiomes was dissimilar in these two different types of individuals. Almost all of the most significant taxonomic changes in the meibum microbiome of individuals with MGD were also present in their eyelid skin, but not in the conjunctiva. Such site-specific microbe pattern changes accompany increases in the gene expression levels controlling carbohydrate and lipid metabolism. Most of the microbiomes in patients with MGD possess a microbe population capable of metabolizing benzoate. Pathogens known to underlie ocular infection were evident in these individuals. MGD meibum contained an abundance of Campylobacter coli, Campylobacter jejuni, and Enterococcus faecium pathogens, which were almost absent from HCs. Functional annotation indicated that in the microbiomes of MGD meibum their capability to undergo chemotaxis, display immune evasive virulence, and mediate type IV secretion was different than that in the microbiomes of meibum isolated from HCs. Conclusions: MGD meibum contains distinct microbiota whose immune evasive virulence is much stronger than that in the HCs. Profiling differences between the meibum microbiome makeup in HCs and patients with MGD characterizes changes of microbial communities associated with the disease status.