Evaluating Truenat Assay for the Diagnosis of Ocular Tuberculosis and Detection of Drug Resistance.

BACKGROUND: Truenat MTB Plus assay was evaluated for diagnosing ocular tuberculosis (OTB) and detecting multi-drug resistant (MDR) and extremely-drug resistant (XDR) OTB. METHODS: A total of 75 vitreous fluid specimens [five confirmed OTB, 40 clinically suspected OTB and 30 controls] were subjected to Truenat MTB Plus, multiplex PCR, and Xpert Ultra. Chips of Truenat were used for detecting rifampicin, isoniazid, fluoroquinolone and bedaquiline resistance. The performance was compared against culture, composite reference standard, and gene sequencing. RESULTS: The overall sensitivity of TruePlus, MPCR, and Ultra in diagnosing OTB was 66.6%, 73.3%, and 55.5%, respectively. Out of six cases with mutations in rpoB gene, RifR was detected in five by TrueRif and four by Ultra. Three MDR and one XDR-OTB were reported by Truenat. CONCLUSION: Truenat assay along with its strategic chips is a rapid and reliable tool for diagnosis of OTB and detection of drug resistance, including MDR and XDR-OTB.Abbreviations: OTB: Ocular tuberculosis; XDR: Extremely drug resistant; Ultra: Xpert MTB/RIF Ultra; Xpert: Xpert MTB/RIF; PCR: polymerase chain reaction; NAATs: Nucleic acid amplification tests; MDR: Multi Drug Resistant; NSP: National Strategic plan for elimination of tuberculosis; FqR: Fluoroquinolone resistant; BdqR: bedaquiline resistant; TrueRif: Truenat MTB Rif Dx; TruePlus: Truenat Plus; INH: Isoniazid; DST: Drug susceptibility testing; MGIT: Mycobacterial growth indicator tube; CRF: Composite reference standard; PPV: positive predictive value; NPV: negative predictive value; EPTB: extrapulmonary tuberculosis; VF: vitreous fluid; DNA: deoxyribonucleic acid; ATT: antitubercular therapy; RifR: Rifampicin resistance; RifS: Rifampicin susceptible; RifI: Rifampicin indeterminate.

Comparative Evaluation of GeneXpert MTB/RIF Ultra and GeneXpert MTB/RIF for Detecting Tuberculosis and Identifying Rifampicin Resistance in Pars Plana Vitrectomy Samples of Patients with Ocular Tuberculosis.

BACKGROUND: Xpert MTB/RIF Ultra (Ultra) was evaluated for the first time on Ocular tuberculosis (OTB) samples and compared with Xpert. METHODS: Seventy five vitreous fluid samples (3 confirmed OTB, 47 clinically suspected OTB, and 25 controls) were subjected to Ultra, Xpert and Multiplex-PCR and compared against culture, composite reference standard (CRS), and gene sequencing. RESULTS: The sensitivity of Ultra was 50% in diagnosing OTB (100% against culture and 46.8% against CRS). The overall sensitivity of Xpert and MPCR was 16% and 72%, respectively. Xpert missed three culture-positive cases and MPCR detected additional 11. Ultra and Xpert missed two and four cases of RifR, respectively. A total of 13(59%) cases were reported 'trace' by Ultra in which RifR could not be evaluated. CONCLUSION: Ultra outperformed Xpert in diagnosing OTB. The advantage of Ultra's simultaneous RifR detection is lost since the trace bacterial loads in the specimens cause indeterminate results of RifR testing.Abbreviations: OTB: Ocular tuberculosis; Ultra: Xpert MTB/RIF Ultra; Xpert: Xpert MTB/RIF, MPCR: multiplex polymerase chain reaction; NAATs: Nucleic acid amplification tests; MLAMP: multitargeted loop-mediated isothermal amplification; PPV: positive predictive value; NPV: negative predictive value; EPTB: extrapulmonary tuberculosis; VF: vitreous fluid; DNA: deoxyribonucleic acid; ATT: antitubercular therapy; RifR: Rifampicin resistance; RifS: Rifampicin susceptible; RifI: Rifampicin indeterminate.

Uveal effusion syndrome following COVID-19 vaccination.

Purpose: To report a rare case of uveal effusion syndrome following COVID-19 vaccination. Observation: A 71-year-old Asian man presented to his ophthalmologist with blurred vision and noticing distorted lines in his left eye two weeks after the first dose of COVID-19 vaccination. Examination revealed choroidal detachment and he was advised systemic corticosteroids. The symptoms were ignored and the second vaccine dose was taken. After five months, he presented to our clinic with persistent visual complaints. He also had a history of COVID-19 infection three months prior to vaccination. Ocular examination revealed a quiet anterior chamber with annular choroidal detachment consistent with the diagnosis of Type 3 uveal effusion syndrome. B-scan ultrasonography revealed increased choroidal thickness with detachment. Optical coherence tomography showed subretinal fluid with retinal pigment epithelium and choroidal folds. Ultrasound biomicroscopy revealed all around supraciliary effusion in the left eye. The patient was treated with oral prednisolone and mycophenolate mofetil which resulted in complete resolution of uveal effusion and improvement in visual acuity. Conclusions and importance: Uveal effusion syndrome is a rare ocular disease, however it may manifest following COVID-19 vaccination. Our case highlights the importance of a complete ophthalmic examination in patients with ocular symptoms after vaccination.

Detection of viable Mycobacterium tuberculosis in ocular fluids using mRNA-based multiplex polymerase chain reaction.

PURPOSE: Intra ocular tuberculosis (IOTB) can affect nearly any part of the eye and delayed diagnosis can result in permanent loss of vision. mRNA, with the ability to detect viable bacilli just like culture, could serve as an important tool to differentiate whether ocular manifestations of IOTB are due to active infection or hypersensitivity response to dead mycobacteria. METHODS: A total of 19 patients with suspected IOTB and 20 controls (10 patients with active inflammation but no evidence of IOTB and 10 patients with no intraocular inflammation) were included. Vitreous fluid samples were collected from all patients and subjected to DNA and mRNA extraction followed by multiplex polymerase chain reaction (MPCR) using three specific targets for M. tuberculosis, i.e. IS6110, MPB64 and protein b. All samples were also subjected to Gene Xpert MTB/RIF assay. RESULTS: Among the 19 patients in group 1, the highest test positivity was noted for DNA-MPCR (73.7%) followed by mRNA-MPCR (42.1%) and GeneXpert MTB/RIF assay (10.5%). All the three tests were negative in the 20 control samples demonstrating a 100% specificity. The negative predictive value was highest for DNA-MPCR (80%), followed by mRNA-PCR (64.5%) and Xpert MTB/RIF assay (48.8%). All patients with any one test positive were treated with anti-tubercular therapy (ATT) and there was good clinical response noted in all. CONCLUSION: mRNA-based MPCR can be used as a marker for detecting viable M. tuberculosis in IOTB cases.

Bacillary Layer Detachment in Hyper-acute Stage of Acute Posterior Multifocal Placoid Pigment Epitheliopathy: A Case Series.

BACKGROUND: The term bacillary layer detachment (BLD) represents a possible separation between the myoid and ellipsoid component of the inner segment, following insult or injury to the outer retina. It has been described previously in cases of toxoplasma retinochoroiditis, central serous chorioretinopathy, Vogt Koyanagi Harada disease and trauma. PURPOSE: To describe the presence of BLD in Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE). METHOD: Clinical and OCT-based description of three consecutive cases of APMPPE with BLD. RESULT: All the three cases (a 25-year-old female, a 36-year-old male, and a 32-year-old male) presented with unilateral, diminution of vision of acute onset. They were diagnosed as APMPPE and OCT revealed a splitting of the ellipsoid zone, resembling a BLD. All the three cases showed complete resolution by 1 week. CONCLUSION: BLD appears in the acute stage of APMPPE and resolves rapidly within a week.

TLR9 signalling activation via direct ligation and its functional consequences in CD4 + T cells.

CpG Oligodeoxynucleotides (ODNs) are established TLR9 ligands; however, their functional responses in CD4+ T cells are believed to be independent of TLR9 and MyD88. We studied ligand-receptor interactions of ODN 2216 and TLR9 in human CD4+ T cells and assessed their consequences in terms of TLR9 signalling and cell phenotype. We demonstrated that the uptake of ODN 2216, a synthetic TLR9 agonist, is controlled by TLR9 signalling molecules and results in an increase in the expression of TLR9 signalling molecules, regulated via a feedback mechanism. Next, the uptake of ODN 2216 resulted in TLR9 signalling dependent but MyD88 independent increase in expression of TGF-ß. Finally, ODN 2216 treated CD4+ T cells showed an anti-inflammatory phenotype that was similar to Th3 type of regulatory T cells. These Th3-like cells were able to suppress the proliferation of untreated CD4+ T cells. Collectively, our results demonstrate a direct and interdependent relationship between ODN 2216 uptake and TLR9 signalling in CD4+ T cells. Our findings thus pave the way for future research to explore direct modulation of adaptive immune cells, using innate immune ligands, to subvert exaggerated inflammatory responses.

Chronic Uveitis in Children.

OBJECTIVE: To describe the experience of managing chronic childhood uveitis from a tertiary care center in India. METHODS: All children diagnosed as chronic uveitis between January 2005 and December 2012 and on follow-up in Pediatric Rheumatology Clinic and Uveitis Clinic, were eligible for enrollment. Information regarding demographics, type of uveitis, treatment, complications, and surgical procedures was obtained from clinic records. All the enrolled patients were assessed for outcome prospectively and underwent a detailed ophthalmological examination to document visual acuity, refraction, intraocular pressure (IOP), slit lamp examination, fundus examination, and vitreous haze findings. RESULTS: Sixty-seven children with chronic uveitis were enrolled in the study. Anterior uveitis was the commonest type seen in 45 children. Juvenile idiopathic arthritis (JIA) was the commonest known etiology and diagnosis of uveitis was made during routine screening in a majority of the JIA patients. No cause could be identified in 43% patients. After a mean follow-up period of 3.95 ± 1.99 y, only 16% eyes were in remission and off therapy. Prolonged oral glucocorticoids were required, besides other immunosuppressants, to control inflammation in 50% patients. Ocular complications were seen in 87% cases with posterior synechiae, band-shaped keratopathy and cataracts being the commonest complications. CONCLUSIONS: Among patients with chronic uveitis, 43% had no identifiable cause. JIA was the commonest known cause. Significant ocular complications were common. Even after a mean follow-up of 3.95 ± 1.99 y, a vast majority continued to need immunosuppression for control of disease activity.

Precise, simplified diagnostic criteria and optimised management of initial-onset Vogt-Koyanagi-Harada disease: an updated review.

Vogt-Koyanagi-Harada (VKH) disease is a primary autoimmune stromal choroiditis. This review aimed to provide a novel perspective of the disease. We took into account recent developments in the understanding of the disease and crucial progress in investigational modalities of the choroid, which has led to new, simpler diagnostic criteria. We analysed recent novel notions in the literature and new diagnostic tools for VKH. We identified the following updates for VKH disease: (1) A crucial differentiation between the acute initial-onset and the chronic forms of the disease; (2) the integration of new, precise imaging methods to assess choroidal inflammation; (3) the promotion of simplified, more reliable diagnostic criteria for acute initial-onset of the disease, based on the sine qua non presence of diffuse choroiditis, detected with indocyanine green angiography (ICGA) and/or Enhanced Depth Imaging OCT (EDI-OCT); and (4) treatment optimisation through early, vigorous, sustained corticosteroid and nonsteroidal immunosuppression, as the first line of treatment for initial-onset VKH disease, and monitoring subclinical choroidal inflammation during follow-ups. Several studies have shown that most patients could discontinue treatment without an inflammation relapse. ICGA and EDI-OCT represented the methods of choice for precisely monitoring disease evolution. Simplified, precise, new diagnostic criteria allow early diagnosis of VKH. In VKH disease, inflammation exclusively originates in the choroidal stroma. Therefore, in many cases, early, sustained treatment, with dual corticosteroid and nonsteroidal immunosuppressive therapy can result in full "healing", which obviates chronic, uncontrolled, subclinical choroidal inflammation.

Effect of sustained-release long-acting intravitreal dexamethasone implant in patients of non-proliferative diabetic retinopathy undergoing phacoemulsification: A randomized controlled trial.

PURPOSE: Cataract and diabetes, both being a major health care problem, an intervention evaluated for the combination of the two attains paramount importance. The purpose of the study was to determine the role of intraoperative intravitreal dexamethasone implant in patients with diabetic retinopathy with/without macula edema undergoing phacoemulsification. METHODS: The study was a two-arm, single-center, randomized, assessor-blinded trial of 151 patients with type-2 diabetes mellitus and cataract. It had two groups: dexamethasone group (DEX) versus standard of care (SOC) group, i.e. phacoemulsification and intraocular lens (IOL) implantation without injection of dexamethasone drug delivery system (DDS). The number of rescue interventions required, central macular thickness by optical coherence tomography (OCT), Early Treatment Diabetic Retinopathy Study (ETDRS) score, laser flare meter (LFM) values, intraocular pressure (IOP), and grade of diabetic retinopathy (DR) were recorded until three months follow up. Macular thickness and number of rescue medications between the treatment groups were the co-primary outcomes. RESULTS: A statistically significant interaction was present between treatment and time on OCT score (P < 0.001). The requirement of rescue interventions in the dexamethasone DDS group [40.2% (33/82)] was lesser as compared to the SOC group [49.3% (34/69)] at the end of 12 weeks [odds ratio (OR), 0.70 (0.36-1.33)] follow up although not statistically significant (P = 0.343). A statistically significant interaction was present between treatment and time on LFM score (P = 0.003). No statistically significant interaction was present between the treatment and time on visual acuity score (P = 0.08) and IOP score (P = 0.375). CONCLUSION: Dexamethasone implant may have potential as a valuable therapy for patients undergoing cataract surgery with DR with/without macular edema with effects lasting for at least three months.

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.

The Emerging Challenge of Diagnosing Drug-resistant Tubercular Uveitis: Experience of 110 Eyes from North India.

Background: Rapid and timely diagnosis of tubercular uveitis (TBU) is of paramount importance to save these eyes from blindness. The present study was, therefore, undertaken to carry out a comparative evaluation of Gene Xpert MTB/RIF (Xpert), MTBDRplus and Multiplex PCR (MPCR) for the diagnosis of TBU. These tests were performed on vitreous fluid of 110 patients with presumed TBU and 90 controls. rpoB gene sequencing confirmed Rifampicin resistance.Results: Xpert, MTBDRplus and MPCR were positive in 19(17.2%),38 (34.5%) and 79 (71.8 %) patients, respectively. All tests were negative in all controls. Rif resistance was detected in 3 by Xpert and 7 by MTBDRplus. MPCR followed by rpoB gene sequencing detected Rif resistance in 6 cases. One case of false Rif resistance was reported each by MTBDRplus and Xpert.Conclusion: MPCR followed by rpoB sequencing is a robust technique for the diagnosis of paucibacilliary condition like TBU and reliable detection of drug resistance.

Collaborative Ocular Tuberculosis Study Consensus Guidelines on the Management of Tubercular Uveitis-Report 1: Guidelines for Initiating Antitubercular Therapy in Tubercular Choroiditis.

TOPIC: An international, expert-led consensus initiative organized by the Collaborative Ocular Tuberculosis Study (COTS), along with the International Ocular Inflammation Society and the International Uveitis Study Group, systematically developed evidence- and experience-based recommendations for the treatment of tubercular choroiditis. CLINICAL RELEVANCE: The diagnosis and management of tubercular uveitis (TBU) pose a significant challenge. Current guidelines and literature are insufficient to guide physicians regarding the initiation of antitubercular therapy (ATT) in patients with TBU. METHODS: An international expert steering subcommittee of the COTS group identified clinical questions and conducted a systematic review of the published literature on the use of ATT for tubercular choroiditis. Using an interactive online questionnaire, guided by background knowledge from published literature, 81 global experts (including ophthalmologists, pulmonologists, and infectious disease physicians) generated preliminary consensus statements for initiating ATT in tubercular choroiditis, using Oxford levels of medical evidence. In total, 162 statements were identified regarding when to initiate ATT in patients with tubercular serpiginous-like choroiditis, tuberculoma, and tubercular focal or multifocal choroiditis. The COTS group members met in November 2018 to refine these statements by a 2-step modified Delphi process. RESULTS: Seventy consensus statements addressed the initiation of ATT in the 3 subtypes of tubercular choroiditis, and in addition, 10 consensus statements were developed regarding the use of adjunctive therapy in tubercular choroiditis. Experts agreed on initiating ATT in tubercular choroiditis in the presence of positive results for any 1 of the positive immunologic tests along with radiologic features suggestive of tuberculosis. For tubercular serpiginous-like choroiditis and tuberculoma, positive results from even 1 positive immunologic test were considered sufficient to recommend ATT, even if there were no radiologic features suggestive of tuberculosis. DISCUSSION: Consensus guidelines were developed to guide the initiation of ATT in patients with tubercular choroiditis, based on the published literature, expert opinion, and practical experience, to bridge the gap between clinical need and available medical evidence.