Proteomic profile of vitreous in patients with tubercular uveitis.

OBJECTIVE: To elucidate disease-specific host protein profile in vitreous fluid of patients with intraocular inflammation due to tubercular uveitis (TBU). METHODS: Vitreous samples from 13 patients with TBU (group A), 7 with non-TBU (group B) and 9 with no uveitis (group C) were analysed by shotgun proteomics using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). Differentially expressed proteins (DEPs) were subjected to pathway analysis using WEB-based Gene SeT Analysis Toolkit software. RESULTS: Compared to control groups (B + C combined), group A (TBU) displayed 32 (11 upregulated, 21 downregulated) DEPs, which revealed an upregulation of coagulation cascades, complement and classic pathways, and downregulation of metabolism of carbohydrates, gluconeogenesis, glucose metabolism and glycolysis/gluconeogenesis pathways. When compared to group B (non-TBU) alone, TBU displayed 58 DEPs (21 upregulated, 37 downregulated), with an upregulation of apoptosis, KRAS signaling, diabetes pathways, classic pathways, and downregulation of MTORC1 signaling, glycolysis/gluconeogenesis, and glucose metabolism. CONCLUSION: This differential protein profile provides novel insights into the molecular mechanisms of TBU and a baseline to explore vitreous biomarkers to differentiate TBU from non-TBU, warranting future studies to identify and validate them as a diagnostic tool in TBU. The enriched pathways generate interesting hypotheses and drive further research.

Mycobacterium tuberculosis does not show evidence of molecular DNA in human cadaveric ocular tissues in an endemic setting.

BACKGROUND: Mycobacterium tuberculosis (MTB) in latent infection has been demonstrated in pulmonary/extra-pulmonary locations (lung, spleen, liver, kidney, adipose tissue) in autopsy studies, but its presence in ocular tissues in the latent state is not known. METHODS: We conducted molecular and histopathological study of 100 cadaver eyes (50 humans) who died from causes other than tuberculosis (TB) (and were potential candidates for corneal transplantation) to detect MTB in ocular tissues in an endemic setting. After removal of the corneal button, an 8 to 10 mm block of tissue (choroid, retina and part of the vitreous) was excised from the remaining globe for DNA isolation. Gel-based IS6110 and devR3 polymerase chain reaction (PCR) assays were done, followed by real-time PCR using beta actin gene as an internal control. Sixteen randomly selected DNA samples were double checked using a commercial kit for MTB and non-tuberculous mycobacteria (NTM) DNA. The remaining larger part of the globe was subjected to histopathology. RESULTS: The mean age was 65.14 ± 18 years. All 100 samples were negative for both IS6110 and devR, and all 16 samples were negative with NTM MTB commercial kit. All samples were negative with Ziehl-Neelsen stain for acid fast bacilli and none showed any inflammation or granulomatous pathology. CONCLUSIONS: MTB could not be detected in human ocular tissues in latent state in India, a TB-endemic country. This may suggest the inability of MTB to seed ocular tissues in the latent state, unlike other organs which serve as reservoirs for the bacilli in the absence of manifest disease.

Fungal retinitis following influenza virus type A (H1N1) infection.

A 43-year-old male presented with left eye foveal retinits causing an acute visual loss following influenza virus type A infection (H1N1 infection or Swine flu). Considering viral (influenza) etiology, a prompt treatment with oral corticosteroids was started. But an initial poor response prompted an immediate diagnostic vitrectomy, which revealed Candida albicans. The retinitis healed with scar formation following anti-fungal therapy. This case highlights that even in the setting of an acute retinitis in an immunocompetent patient with recent history of viral systemic illness, a high index of suspicion of a fungal (rather than viral) infection should be kept in mind.

Safety and Outcome of Microincision Vitreous Surgery in Uveitis.

PURPOSE: To report the outcome of microincision vitreous surgery (MIVS) in uveitis. METHODS: In total, 103 patients (106 eyes) underwent diagnostic MIVS between March 2012 and April 2015. Postoperative evaluation included vitreous haze grading from clinical/electronic records, best-corrected visual acuity (BCVA), and complications. RESULTS: Mean age was 36.8 ± 13.9 years (range: 8-80 years). Mean follow-up after MIVS was 12.2 ± 7.2 months (median 12 months). Mean vitreous haze grading was 2.39 ± 0.98 (preoperatively), 0.36 ± 0.73 postoperatively (1 week), and 0.02 ± 0.2 at 1 month (p < 0.001). Mean BCVA was 1.5 ± 1.0 logMAR preoperatively and 0.72 ± 0.68 logMAR at 1 month (p = 0.000). Postoperative complications included cataract (14.6%), rise in intraocular pressure (13.2%), vitreous hemorrhage (4.7%), hypotony (3.2%), retinal detachment (2.8%), epiretinal membrane (2.8%), and worsening of inflammation (0.9%). CONCLUSIONS: MIVS is safe and may have a therapeutic role in uveitis.