Project description:PurposeTo investigate the development of corneal neovascularization, the corneal expression of vascular endothelial growth factor (VEGF), and the antiangiogenic effects of a VEGF-inhibitory antibody during experimental keratomycosis.MethodsScarified corneas of BALB/c mice were topically inoculated with Candidaalbicans and monitored daily for corneal neovascularization. A murine gene microarray compared infected corneas to controls 1 day after inoculation. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) determined levels of genes encoding VEGF-A, VEGF-B, VEGF-C, and VEGF-D and placental growth factor in infected, mock-inoculated, and normal corneas. Immunostaining localized VEGF-A in corneal sections. An anti-VEGF-A antibody that binds to murine VEGF was evaluated for effects on corneal neovascularization and fungal recovery.ResultsEyes with C. albicans keratitis manifested limbal capillary budding on the second postinoculation day, and intrastromal neovascular tufts subsequently grew at a mean rate of 250+/-80 microm/day. One day after the onset of C. albicans keratitis, VEGF-A was upregulated 12.5 fold (p=0.01) by microarray and 8.8 fold (p=0.004) by real-time RT-PCR, followed by a measured decline toward baseline over one week. VEGF-A was present in the epithelium and stroma of infected corneas. Scarification alone did not alter VEGF expression compared to the normal cornea. Anti-VEGF-A antibody significantly (p<0.01) decreased the formation of new corneal blood vessels during experimental keratomycosis without adversely affecting the fungal load of C. albicans keratitis.ConclusionsUntreated C. albicans keratitis induces VEGF-A and leads to progressive corneal neovascularization that is preventable by a VEGF-blocking antibody.
Project description:MicroRNAs (miRNAs) are small, stable non-coding RNA molecules with regulatory function and marked tissue specificity that post-transcriptionally regulate gene expression, however their role in fungal keratitis remain unknown. Our purpose was to identify the miRNAs in human cornea from fungal keratitis patients and understand their key role in regulation of pathogenesis. Corneal samples from normal cadaver (n=3) and fungal keratitis (n=5) patients were pooled separately and total RNA was extracted. Deep sequencing was done using Illumina HiSeq1000 platform to identify miRNA profile. We identified seventy five differentially expressed miRNAs in fungal keratitis corneas. Select miRNAs were validated by real-time RT-PCR (Q-PCR). We predicted their role in regulating target genes in several pathways by combining miRNA target genes and pathway analysis, and mRNA expression of select target genes were further analysed by Q-PCR. MiR-21-5p, miR-223-3p, miR-146b-5p, miR-155-5p, miR-511-5p were found to be involved in inflammatory and immune responses, regulating Toll like receptor signaling pathways, which is of particular interest. MiR-451a with an increased expression in keratitis may have a role in wound healing by targeting Macrophage Migration Inhibitory Factor (MIF). Further, we highlighted that Neurotrophin signaling pathway may play a role in wound healing process. One novel miRNA was also detected in cornea. In conclusion, several miRNAs with high expression in fungal keratitis corneas point towards their role in regulation of pathogenesis. Further insights in understanding miRNAs role in wound healing and inflammation may help design new therapeutic strategies.
Project description:Bacterial keratitis results in corneal scarring and subsequent visual impairment. The long-term evolution of corneal scars has not been well described. In this case series, we identified patients who had improvement in corneal scarring and visual acuity from a clinical trial for bacterial keratitis.We searched the records of the Steroids for Corneal Ulcers Trial (SCUT) for patients who had improvement in vision between the 3-month and 12-month visits and reviewed their clinical photographs.Of the 500 patients enrolled in SCUT, five patients with large central corneal scars due to bacterial keratitis are presented. All experienced improvement in rigid contact lens-corrected visual acuity from months 3 to 12. All patients also had marked improvement in corneal opacity during the same time period. None of the patients opted to have penetrating keratoplasty.Corneal scars may continue to improve even many months after a bacterial corneal ulcer has healed. The corneal remodeling can be accompanied by considerable improvement in visual acuity, such that corneal transplantation may not be necessary.
Project description:MicroRNAs (miRNAs) are small, stable non-coding RNA molecules with regulatory function and marked tissue specificity that post-transcriptionally regulate gene expression, however their role in fungal keratitis remain unknown. Our purpose was to identify the miRNAs in human cornea from fungal keratitis patients and understand their key role in regulation of pathogenesis. Corneal samples from normal cadaver (n=3) and fungal keratitis (n=5) patients were pooled separately and total RNA was extracted. Deep sequencing was done using Illumina HiSeq1000 platform to identify miRNA profile. We identified seventy five differentially expressed miRNAs in fungal keratitis corneas. Select miRNAs were validated by real-time RT-PCR (Q-PCR). We predicted their role in regulating target genes in several pathways by combining miRNA target genes and pathway analysis, and mRNA expression of select target genes were further analysed by Q-PCR. MiR-21-5p, miR-223-3p, miR-146b-5p, miR-155-5p, miR-511-5p were found to be involved in inflammatory and immune responses, regulating Toll like receptor signaling pathways, which is of particular interest. MiR-451a with an increased expression in keratitis may have a role in wound healing by targeting Macrophage Migration Inhibitory Factor (MIF). Further, we highlighted that Neurotrophin signaling pathway may play a role in wound healing process. One novel miRNA was also detected in cornea. In conclusion, several miRNAs with high expression in fungal keratitis corneas point towards their role in regulation of pathogenesis. Further insights in understanding miRNAs role in wound healing and inflammation may help design new therapeutic strategies. Control and fungal keratitis, human corneal miRNA profiles were generated using IlluminaHiseq1000 platform
Project description:Lymphatic vessels play a crucial role in systemic immune response and regulation of tissue fluid homeostasis. Corneal lymphangiogenesis in bacterial keratitis has not been studied. In this study, we investigated the mechanism and the role of corneal lymphangiogenesis in a murine bacterial keratitis model using Pseudomonas aeruginosa. We first demonstrated that corneal lymphangiogenesis was enhanced mainly in the late stage of bacterial keratitis, contrary to corneal angiogenesis that started earlier. Corresponding to the delayed lymphangiogenesis, expression of the pro-lymphangiogenic factors VEGF-C and VEGFR-3 increased in the late stage of bacterial keratitis. We further found that F4/80 and CD11b positive macrophages played an essential role in corneal lymphangiogenesis. Notably, macrophages were specifically involved in corneal lymphangiogenesis in the late stage of bacterial keratitis. Finally, we demonstrated the beneficial role of corneal lymphangiogenesis in ameliorating the clinical course of bacterial keratitis. Our study showed that bacterial activity was not directly involved in the late stage of keratitis, while corneal lymphangiogenesis reduced corneal edema and clinical manifestation in the late stage of bacterial keratitis. These findings suggest that the process of lymphangiogenesis in bacterial keratitis ameliorates corneal inflammation and edema in the late stage of bacterial keratitis.
Project description:Keratitis is the main cause of corneal blindness worldwide. Most vision loss caused by keratitis can be avoidable via early detection and treatment. The diagnosis of keratitis often requires skilled ophthalmologists. However, the world is short of ophthalmologists, especially in resource-limited settings, making the early diagnosis of keratitis challenging. Here, we develop a deep learning system for the automated classification of keratitis, other cornea abnormalities, and normal cornea based on 6,567 slit-lamp images. Our system exhibits remarkable performance in cornea images captured by the different types of digital slit lamp cameras and a smartphone with the super macro mode (all AUCs>0.96). The comparable sensitivity and specificity in keratitis detection are observed between the system and experienced cornea specialists. Our system has the potential to be applied to both digital slit lamp cameras and smartphones to promote the early diagnosis and treatment of keratitis, preventing the corneal blindness caused by keratitis.
Project description:In this research, polyvinyl-alcohol (PVA)/gelatin (GEL)/propolis (Ps) biocompatible nanofiber patches were fabricated via electrospinning technique. The controlled release of Propolis, surface wettability behaviors, antimicrobial activities against the S. aureus and P. aeruginosa, and biocompatibility properties with the mesenchymal stem cells (MSCs) were investigated in detail. By adding 0.5, 1, and 3 wt.% GEL into the 13 wt.% PVA, the morphological and mechanical results suggested that 13 wt.% PVA/0.5 wt.% GEL patch can be an ideal matrix for 3 and 5 wt.% propolis addition. Morphological results revealed that the diameters of the electrospun nanofiber patches were increased with GEL (from 290 nm to 400 nm) and Ps addition and crosslinking process cause the formation of thicker nanofibers. The tensile strength and elongation at break enhancement were also determined for 13 wt.% PVA/0.5 wt.% GEL/3 wt.% Ps patch. Propolis was released quickly in the first hour and arrived at a plateau. Cell culture and contact angle results confirmed that the 3 wt.% addition of propolis reinforced mesenchymal stem cell proliferation and wettability properties of the patches. The antimicrobial activity demonstrated that propolis loaded patches had antibacterial activity against the S. aureus, but for P. aeruginosa, more studies should be performed.
Project description:PurposeTo describe a case of rapid keratitis and corneal perforation after epithelium off collagen cross-linking.ObservationsWe report a case of a 17-year-old male who underwent collagen cross-linking with the protocol and device approved by the United States Food and Drug Administration (FDA) that developed a corneal infiltrate 3 days after the procedure. He later developed corneal thinning and perforation on day 5 requiring the use of cyanoacrylate glue and a Kontur lens. Despite initial improvement in the infiltrate with fortified antibiotics he later had leakage of aqueous around the glue and a flat chamber requiring an emergent penetrating keratoplasty on postoperative day 16.Conclusion and importanceWhile collagen cross-linking has been very effective for treating keratoconus and is being recommended more frequently since FDA approval in the United States, severe complications such as corneal perforation requiring early transplant can still occur.
Project description:PurposeMacular Corneal Dystrophy (MCD, MIM #217800) is a category 1 corneal stromal dystrophy as per the current IC3D classification. While characterized by macular stromal deposits, we report a case of MCD type II with isolated bilateral peripheral Decemet membrane opacities, describing the clinical features and results of screening the CHST6 gene and serum sulfated keratan sulfate levels.ObservationsA 68-year-old man with an unremarkable past medical and family history presented with bilateral progressive decrease in vision. Ocular exam revealed bilateral clear corneas with the exception of peripheral, round, gray-white discrete deposits at the level of Descemet membrane and decreased central corneal thickness in both eyes. The morphology of the corneal deposits, decreased corneal thickness and the absence of a family history were consistent with MCD, prompting screening of the CHST6 gene. Sanger sequencing followed by allele specific cloning revealed compound heterozygous CHST6 mutations in trans configuration: c.-26C > A, which created a new upstream open reading frame (uORF'), predicted to attenuate translation efficiency of the downstream main ORF; and c.803A > G (p.(Tyr268Cys)), previously associated with MCD. Serum keratan sulfate was reduced but detectable, consistent with the diagnosis of macular corneal dystrophy type II.ConclusionsAlthough macular corneal dystrophy is classified as a corneal stromal dystrophy with endothelial involvement, we report a case of MCD with dystrophic deposits confined to the peripheral Descemet membrane, indicating that MCD may be associated with isolated endothelial involvement.