Drug-resistant tubercular uveitis

Adjunctive Intravitreal Anti-vascular Endothelial Growth Factor and Moxifloxacin Therapy in Management of Intraocular Tubercular Granulomas

PURPOSE

To report pre and post treatment levels of VEGF-A in the aqueous humour of patients with intraocular tubercular granulomas and study the effect of a combined intravitreal anti-VEGF bevacizumab and moxifloxacin therapy on their regression.

METHODS

Aqueous samples of 10 consecutive patients with intraocular tubercular granulomas obtained before and after initiating treatment were subjected to ELISA for analysing intraocular VEGF-A levels. Intravitreal injections of bevacizumab and moxifloxacin were given weekly till complete regression of these granulomas. All patients received the usual four-drug ATT and oral corticosteroids.

RESULTS

Mean baseline VEGF-A level was 1004.27±411.40 pg/ml (401.32-1688.95) that reduced significantly to 27.62±46.86 pg/ml (6.9-131.83) at the last injection. Meannumber of intravitreal injections was 3.1 (2-4). We found significant correlation of decreasing levels of aqueous VEGF-A with the clinical regression of these tubercular granulomas.

CONCLUSIONS

Intraocular TB granulomas have high levels of VEGF-A. Weekly intravitreal injections of anti-VEGF bevacizumab with moxifloxacin as an adjunct to the standard care may cause prompt regression of tubercular granulomas.

ABBREVIATIONS

TB: Tuberculosis; IOTB: Intraocular tuberculosis; VEGF: Vascular endothelial growth factor; RD: Retinal detachment; Mtb: Mycobacterium tuberculosis; ATT: Antitubercular therapy; AMD: Age-related macular degeneration; SRF: Subretinal fluid; ELISA: Enzyme immunosorbent assay; PCR: Polymerase chain reaction; ONH: Optic nerve head; MDR-TB: Multidrug-resistant tuberculosis; pg/ml: picogram/milliliter; ESR: Erythrocyte sedimentation rate; CECT: Contrast enhanced computed tomography; DNA: Deoxyribonucleic acid; RNA: Ribonucleic acid; BSL: Biosafety level; BCVA: Best corrected visual acuity; HM: Hand movements; KP: Keratic precipitates; PSC: Posterior subcapsular cataract; PS: Posterior synechiae; CRA: Chorio-retinal atrophy; IVMP: Intravenous methyl prednisolone; OCT: Optical coherence tomography; RPE: Retinal pigment epithelium; FFA: Fundus fluorescein angiography; ICG: Indocyanine angiography; RAP: Retinal arterial proliferans.

Global prevalence and clinical outcomes of tubercular uveitis: a systematic review and meta-analysis

Tubercular uveitis (TBU) is an inflammation/infection of the eye secondary to Mycobacterium tuberculosis infection. The difficulty in making the diagnosis has resulted in variable prevalence and clinical response rates. We aimed to determine the global prevalence of TBU in uveitis patients stratified by TB high-burden countries (HBCs) and non-HBCs and by geographic regions and the clinical response of TBU to antitubercular treatment We performed a systematic review and meta-analysis of TBU studies published in PubMed, Scopus and EMBASE, up to June 30, 2020. A random effects model was used for all meta-analyses. Of 5,018 articles identified, 70 prevalence studies (65,607 uveitis and 3,166 TBU cases) and 18 clinical outcome studies (1,570 TBU cases; 1,304 responded to anti-tubercular therapy [ATT]) were analyzed. The overall weighted prevalence of TBU was 4.0% (95% CI, 3-5); in TB HBCs it was 7.0% (95% CI, 5-11), non-HBCs 3.0% (95% CI, 2-4), and sub-Saharan Africa 11.0% (95% CI, 8-15). The overall weighted clinical response was 82.0% (95% CI, 75-89). Despite the difficulty in diagnosing TBU, the prevalence is expectantly higher in HBCs, and sub-Saharan Africa and the clinical outcome is poor. Standardization of diagnostic criteria and ATT is warranted in future cohort studies.

Tuberculous Scleritis and Multidrug Resistance

Purpose: To present a case of necrotizing sclerokeratitis in a patient with multidrug-resistant tuberculosis and study the challenges in diagnosis and management of anterior tuberculous scleritis.Methods: Retrospective observational case report and review of anterior tuberculous scleritis.Results: A 28-year-old woman, previously diagnosed as presumed tubercular panuveitis, presented with necrotizing sclerokeratitis and progressed to develop panophthalmitis. Laboratory investigations revealed multidrug-resistant Mycobacterium tuberculosis as the etiological agent. We reviewed cases of anterior tuberculous scleritis published in the literature, with regards to clinical features, microbiological investigations, treatment, and outcomes. Treatment includes standard antitubercular therapy, with or without systemic corticosteroids. Poor response to treatment is seen either due to delayed diagnosis or drug resistance, and the significance of the same is highlighted in our case.Conclusion: Diagnosis of tuberculous scleritis is a challenge. Therapeutic failure must alert the clinician for drug resistance which is diagnosed early, can prevent the devastating outcomes.

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.

Laboratory investigations in uveitis: current practice and future directions

Diagnosis and management of uveitis always remains a challenge to the treating ophthalmologists. Rapid diagnosis and timely initiation of appropriate, effective treatment in uveitis are the critical determinants that lead to good visual outcome and reduce the risk of ocular morbidity. In the last decade, significant progress has been made in molecular diagnostic modalities and in development of newer diagnostic tools, which included serological tests and imaging techniques. However, a tailored approach to laboratory investigations based on meticulous history and comprehensive ocular evaluation has been propounded as the gold standard for successful management of an uveitic entity. In this article, we review the laboratory diagnostic tests in uveitis as well as recent technological advances in laboratory science, which may be the future direction for diagnosis of uveitis.

MTBDRplus for the rapid diagnosis of ocular tuberculosis and screening of drug resistance

PurposeTimely diagnosis of intraocular tuberculosis (IOTB) along with detection of drug resistance can save many eyes from visual impairment. With the growing incidence of IOTB and rising drug resistance, a reliable diagnostic platform for simultaneous detection of the agent and mutated gene is urgently needed. The MTBDRplus assay was evaluated directly on vitreous fluid samples for the same.Patients and methodsIn a prospective study, The MTBDRplus assay was performed on 127 vitreous fluid samples (77 'study group' comprising cases of presumed ocular tuberculosis and 50 'control group' cases of disease controls (n=25) and non-uveitic controls (n=25)). All samples positive by MTBDRplus assay were subjected to gene sequencing to confirm the mutations for rifampicin and isoniazid resistance.ResultsThe MTBDRplus assay produced a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 36.36%, 100%, 100%, and 50.50%, respectively, for the detection of IOTB. Among the 28 cases from study group that were positive by MTBDRplus assay, rifampicin resistance was reported in six and isoniazid resistance in two cases. On sequencing of rpoB and katG gene, one case of false rifampicin-resistant by MTBDRplus was found. The other resistant isolates showed concordant mutations between MTBDRplus assay and sequencing.ConclusionThe MTBDRplus assay is an effective tool for the rapid diagnosis of IOTB along with detection of drug resistance, thereby improving the outcome in IOTB.