Ocular Tuberculosis--A Clinical Conundrum

The Spectrum of Presumed Tubercular Uveitis in a Referral Eye Clinic in Qatar

PURPOSE

To analyze the clinical spectrum of patients with presumed tubercular uveitis in a referral eye clinic in Qatar.

METHODS

We retrospectively reviewed the clinical records of 50 patients (80 eyes) diagnosed with presumed ocular tuberculosis who presented to the uveitis clinic, department of Ophthalmology Hamad Medical Corporation, Qatar, from January 2014 till December 2019.

RESULTS

Mean age at presentation was 34.5 ± 9.3 years. Forty one patients were males (82%) and 30 patients had bilateral involvement (60%). Forty eyes (50%) had posterior uveitis, 21 eyes (26.3%) intermediate uveitis, 11 eyes (13.7%) panuveitis, and 8 eyes (10%) anterior uveitis. Ocular findings included vitritis in 82.5% of eyes, retinal vasculitis in 46.3% (92% of which were occlusive in nature), multifocal choroiditis in 18.8%, serpiginous-like choroiditis in 11.3%, Most common complications at presentation or during follow-up included macular edema in 32 eyes (40%), preretinal or optic disc neovascularization in 29 eyes (36.3%) and vitreous hemorrhage in 17 eyes (21.3%). Anti-tubercular treatment was provided to 46 patients (92%). Systemic corticosteroids and corticosteroid sparing agents were associated, respectively, in 39 patients (78%) and 14 patients (28%). After 1 year of follow up, inflammation was controlled, with a significant improvement in visual acuity (p < 0.0001).

CONCLUSIONS

In Qatar, tubercular uveitis has a broad spectrum of ocular features, with posterior and intermediate uveitis being the most common anatomic forms. Vitritis, multifocal choroiditis without or with a serpiginous-like pattern, and occlusive retinal vasculitis are the most common ocular findings. Main sight-threatening ocular complications are macular edema, posterior segment neovascularization, and vitreous hemorrhage.

Pediatric Posterior Infectious Uveitis

PURPOSE

To describe the most important cause of infectious posterior uveitis in pediatric patients.

METHODS

Review of the literature.

RESULTS

The most important causes of infectious uveitis in pediatric patients are: cat-scratch disease, toxocariasis, tuberculosis, viral diseases and toxoplasmosis. Ocular manifestations include retinitis, neuroretinitis, choroidal granulomas, peripheral granulomas and posterior pole granulomas.

CONCLUSION

Infectious posterior uveitis is a challenging subject and should be considered in the differential diagnosis of any posterior uveitis in children. Infectious uveitis must be excluded before initiating immunosuppressive therapy.

Regional homogeneity alterations in multifrequency bands in patients with extracranial multi-organ tuberculosis: a prospective cross-sectional study

Background

This study aimed to clarify the spontaneous neural activity in the conventional frequency band (0.01-0.08 Hz) and 2 subfrequency bands (slow-4: 0.027-0.073 Hz; slow-5: 0.01-0.027 Hz) in patients with extracranial multi-organ tuberculosis (EMTB) through regional homogeneity (ReHo) analysis.

Methods

In all, 32 patients with EMTB and 31 healthy controls (HCs) were assessed by resting-state functional magnetic resonance imaging (rs-fMRI) scans to clarify the abnormal spontaneous neural activity through ReHo analysis in the conventional frequency band and 2 subfrequency bands.

Results

Compared with the HCs, the patients with EMTB exhibited decreased ReHo in the left postcentral gyrus [t=-4.79; 95% confidence interval (CI): -0.79 to -0.31] and the left superior cerebellum (t=-4.45; 95% CI: -0.54 to -0.21) in the conventional band. Conversely, increased ReHo was observed in the right middle occipital gyrus (t=3.94; 95% CI: 0.18-0.53). In the slow-4 band, patients with EMTB only exhibited decreased ReHo in the superior cerebellum (t=-4.69; 95% CI: -0.54 to -0.22); meanwhile, in the slow-5 band, these patients exhibited decreased ReHo in the right postcentral gyrus (t=-3.76; 95% CI: -0.74 to -0.21) and the left superior cerebellum (t=-5.20, 95% CI: -0.72 to -0.31). After Bonferroni correction, no significant correlation was observed between the ReHo values in clusters showing significant between-group differences and cognitive test scores.

Conclusions

ReHo showed abnormal synchronous neural activity in patients with EMTB in different frequency bands, which provides a novel understanding of the pathological mechanism of EMTB.

An excursion into ocular tuberculosis

Till today, ocular tuberculosis (OTB) presents clinicians with significant challenges in diagnosis and management. There is no one-size-fits-all approach to a heterogeneous disease like OTB, and clinicians often have to consider a multitude of factors when initiating treatment, such as tuberculosis endemicity, the probability of a true OTB diagnosis in the setting of nonspecific ocular features, the effective duration of treatment, and the likelihood of vision-threatening complications in the patient. It is no wonder that treatment protocols are widely varied globally. There have been recent developments in the standardization of nomenclature and therapeutic strategies for OTB, as established by the Collaborative OTB Study Working Group. In this review, we referred to findings in retrospective studies, international clinical guidelines, and OTB consortiums, to explore the clinical presentations, investigations, and updated management principles for patients with presumed tubercular uveitis.

Intraocular Tuberculosis: A Challenging Case Mimicking Wet Age-Related Macular Degeneration

An otherwise healthy 72-year-old Chinese patient diagnosed with exudative age-related macular degeneration and decreased vision in left eye was fully investigated. The retrospective analysis of past multimodal imaging revealed bilateral severe choroidal neovascularization and choroiditis associated with a positive tuberculin skin testing and interferon-gamma release assay (QuantiFERON-TB Gold - Cellestis^®, Chadstone, VIC, Australia) suggestive of latent ocular tuberculosis. The variable presentation and tests' results interpretation represent the greatest limitations in understanding and treating intraocular TB (IOTB). This may present without any other systemic symptoms, the intraocular tissues are of limited access to biopsies and other tests, including imaging and immunological tests, are of relative value. This case highlights how variable may be the presentation of IOTB, which can be easily misdiagnosed leading to a delayed treatment and worse prognosis.

Role of interferon gamma release assay in the diagnosis and management of Mycobacterium tuberculosis-associated uveitis: a review

Tuberculosis (TB)-associated uveitis is a common cause of infectious uveitis in the developing world. Diagnosis of TB uveitis remains a challenge. The role of interferon gamma release assays (IGRAs) is uncertain. Herein we summarise the available literature on the utility of IGRAs in the diagnosis and management of TB uveitis. We searched PubMed database from 1 August 2010 to 31 July 2020 using the following keywords alone and in combination: 'interferon-gamma release assay', 'QuantiFERON', 'T-SPOT.TB', 'TB uveitis', 'serpiginous like choroiditis', 'tuberculoma', 'TB vasculitis', 'TB panuveitis' and 'ocular tuberculosis'. Data from 58 relevant studies were collated. The review is focused on currently marketed versions of IGRA tests: QuantiFERON-TB Gold In-Tube assay, QuantiFERON-TB Gold Plus assay (QFT-Plus) and T-SPOT.TB. We found limited evidence regarding the diagnostic utility of IGRA in patients with uveitis. No study was identified evaluating the newer QFT test-the QFT-Plus-in patients with uveitis. Similarly, there is lack of data directly comparing QFT-Plus with T-SPOT.TB specifically for the diagnosis of TB uveitis.

Choroidal granuloma resolution with tuberculosis treatment

Purpose

To report a case of presumed ocular tuberculosis, successfully treated with anti-tubercular therapy alone.

Observations

Resolution of a presumed tubercular choroidal granuloma occurred after initiation of 4-drug anti-tubercular therapy, without any adjunct corticosteroid treatment.

Conclusions

Though corticosteroids are commonly used as adjunctive treatment for ocular tuberculosis, treatment with anti-tubercular therapy alone is possible in select patients with close follow-up.

Ocular tuberculosis: Where are we today?

Diagnosis and management of ocular tuberculosis (OTB) poses a significant challenge. Mixed ocular tissue involvement and lack of agreement on best practice diagnostic tests together with the global variations in therapeutic management contributed to the existing uncertainties regarding the outcome of the disease. The current review aims to update recent progress on OTB. In particular, the Collaborative Ocular Tuberculosis Study (COTS) group recently standardized a nomenclature system for defining clinical phenotypes, and also proposed consensus guidelines and an algorithmic approach for management of different clinical phenotypes of OTB. Recent developments in experimental research and innovations in molecular diagnostics and imaging technology have provided a new understanding in the pathogenesis and natural history of the disease.

The Collaborative Ocular Tuberculosis Study (COTS)-1: A Multinational Descriptive Review of Tubercular Uveitis in Paediatric Population

PURPOSE

To examine disease profile of tubercular uveitis (TBU) in Paediatric population.

METHODS

Among 945 patients of the retrospective multinational study by the Collaborative Ocular Tuberculosis Study (COTS)-1, 29 Paediatric patients diagnosed with TBU were analyzed.

RESULTS

Mean age of disease presentation was 12.8 (range 4-18 years), with predominance of males (n = 14/20; 70.0%) and Asian ethnicity (n = 25/29; 86.2%). Posterior uveitis (n = 14/28; 50%) was the most frequent uveitis phenotype, with choroidal involvement occurring in 64.7% (n = 11/17). Incidence of optic disc edema and macular edema was higher in children (n = 8/18; 44.4% and n = 5/18; 27.8%, respectively) than in adults (n = 160/942; 16.9% and n = 135/942; 14.3%, respectively). Comparison of optic disc edema between subgroups showed a significant difference (P =.006). All patients received oral corticosteroids, most of them with antitubercular therapy. Treatment failure developed in 4.8% (n = 1/21).

CONCLUSIONS

Children have a more severe inflammatory response to the disease, and an intensive anti-inflammatory therapeutic regimen is required to achieve a positive treatment outcome.

Management of Intraocular Infections in HIV

Purpose: Overview of treatment options for the most common intraocular opportunistic infections in patients with acquired immunodeficiency syndrome (AIDS), including ocular syphilis, ocular tuberculosis, toxoplasmic chorioretinitis, and viral retinitis. Method: Narrative Review. Results: Despite the huge advances in the development of combined antiretroviral therapy (cART) for the management of patients with human immunodeficiency virus (HIV) infection, opportunistic infections still represent a significant diagnostic dilemma and cause of ocular morbidity in patients with HIV. Conclusion: Although the treatment of intraocular infections in patients with AIDS may be challenging, prompt assessment of the clinical features and appropriate aggressive management of the underlying etiology are critical to avoid life and vision threatening.

Cytopathology and Polymerase Chain Reaction of Vitreous Fluid in Tubercular Intermediate Uveitis

Purpose: Cytopathology of vitreous is most commonly done to diagnose vitreoretinal lymphoma in eyes with nonspecific inflammation. Vitreous cytopathology features of tuberculous intermediate uveitis have not been described in literature.Case report: We report a case of a healthy 35-year-old female who showed granulomatous inflammatory changes on vitreous cytopathology with polymerase chain reaction confirming a diagnosis of intraocular tuberculosis.Conclusion: This case highlights the role of cytopathology in determining the etiology and pathogenesis behind the elusive diagnosis of intermediate uveitis. Polymerase chain reaction can further help in confirming the diagnosis and allowing commencement of appropriate therapy.

Clinical Profile and Treatment Response of Patients with Ocular Inflammation due to Presumed Ocular Tuberculosis: A Retrospective Study

Objectives:

Ocular tuberculosis is an extrapulmonary tuberculous infection and has varying manifestations which pose a huge challenge to diagnosis and treatment. The purpose of this study is to describe the various clinical manifestations of ocular inflammations due to tuberculosis and to assess the response to treatment following antituberculous therapy (ATT) and corticosteroids in these patients.

Materials and Methods:

We performed a retrospective analysis of 29 patients with presumed ocular tuberculosis who were started on ATT and completed follow-up of at least 6 months after ATT was initiated. The data collected were: age at presentation, sex, laterality, presence or absence of pulmonary/extrapulmonary tuberculosis, history of exposure to tuberculosis, site of ocular involvement and duration of illness, visual acuity at presentation and at 6-month follow-up, and response to treatment.

Results:

Most of the patients were of economically productive age, between 21-60 years. This most common presentation in our study population was unilateral nongranulomatous anterior uveitis. In spite of the delay between symptom onset and start of therapy, favorable response was noted in 79.3% of patients at completion of 6 months of ATT. The various reasons for the delay in start of therapy were also evaluated.

Conclusion:

In this case series, we presented the various ocular manifestations and the difficulties faced in the diagnosis of presumed ocular tuberculosis. Outcomes of ATT were favorable in most of our patients. Thus, the clinician should exercise a very high degree of suspicion and should not withhold a trial of ATT.

A case report of ocular tuberculosis in a patient with membranous nephropathy

RATIONALE

Membranous nephropathy (MN), a chronic kidney disease (CKD), due to hypoproteinemia, malnutrition, anemia, long-term intake of immunosuppressive agents, changes in cellular immune state, and decrease in antimicrobial peptides, is a high risk for Mycobacterium tuberculosis (MTB) infection, which can cause tuberculosis (TB). TB manifests by various clinical symptoms. Ocular symptoms is a rare presentation of TB. Here, we describe a case of ocular tuberculosis in a patient with MN.

PATIENT CONCERNS

A 63-year-old man with membranous nephropathy (MN) history presented with ocular symptoms.

DIAGNOSES

According to the pathological manifestations of ocular tissue biopsy and a positive polymerase chain reaction (PCR) on samples from sputum and bronchoalveolar lavage fluid (BALF), we elicited a diagnosis of disseminated tuberculosis.

INTERVENTION

The patient received antituberculous therapy and immunosuppressive therapy.

OUTCOMES

The clinical manifestations significantly improved.

LESSONS

Clinicians should be aware of the possibility of TB in cases of immunocompromised patients and perform an appropriate diagnostic work-up for TB.

Transcriptional Profile of Mycobacterium tuberculosis in an in vitro Model of Intraocular Tuberculosis

Background: Intraocular tuberculosis (IOTB), an extrapulmonary manifestation of tuberculosis of the eye, has unique and varied clinical presentations with poorly understood pathogenesis. As it is a significant cause of inflammation and visual morbidity, particularly in TB endemic countries, it is essential to study the pathogenesis of IOTB. Clinical and histopathologic studies suggest the presence of Mycobacterium tuberculosis in retinal pigment epithelium (RPE) cells. Methods: A human retinal pigment epithelium (ARPE-19) cell line was infected with a virulent strain of M. tuberculosis (H37Rv). Electron microscopy and colony forming units (CFU) assay were performed to monitor the M. tuberculosis adherence, invasion, and intracellular replication, whereas confocal microscopy was done to study its intracellular fate in the RPE cells. To understand the pathogenesis, the transcriptional profile of M. tuberculosis in ARPE-19 cells was studied by whole genome microarray. Three upregulated M. tuberculosis transcripts were also examined in human IOTB vitreous samples. Results: Scanning electron micrographs of the infected ARPE-19 cells indicated adherence of bacilli, which were further observed to be internalized as monitored by transmission electron microscopy. The CFU assay showed that 22.7 and 8.4% of the initial inoculum of bacilli adhered and invaded the ARPE-19 cells, respectively, with an increase in fold CFU from 1 dpi (0.84) to 5dpi (6.58). The intracellular bacilli were co-localized with lysosomal-associated membrane protein-1 (LAMP-1) and LAMP-2 in ARPE-19 cells. The transcriptome study of intracellular bacilli showed that most of the upregulated transcripts correspond to the genes encoding the proteins involved in the processes such as adherence (e.g., Rv1759c and Rv1026), invasion (e.g., Rv1971 and Rv0169), virulence (e.g., Rv2844 and Rv0775), and intracellular survival (e.g., Rv1884c and Rv2450c) as well as regulators of various metabolic pathways. Two of the upregulated transcripts (Rv1971, Rv1230c) were also present in the vitreous samples of the IOTB patients. Conclusions:M. tuberculosis is phagocytosed by RPE cells and utilizes these cells for intracellular multiplication with the involvement of late endosomal/lysosomal compartments and alters its transcriptional profile plausibly for its intracellular adaptation and survival. The findings of the present study could be important to understanding the molecular pathogenesis of IOTB with a potential role in the development of diagnostics and therapeutics for IOTB.

Diminished TLR2-TLR9 mediated CD4+ T cell responses are associated with increased inflammation in intraocular tuberculosis

Intraocular tuberculosis (IOTB) is amongst the leading causes of uveitis in tropical countries. Despite reports on involvement of proinflammatory cytokines, studies on innate immune responses in disease pathogenesis are lacking. Reports from animal models and patients with pulmonary tuberculosis indicate that defects in toll like receptor (TLR)2 and TLR9 signalling predispose them to tuberculosis. In this context, we investigated the role of TLR2, TLR4 and TLR9 in generation of CD4+ T effector (Teff) cell responses during IOTB. Firstly, the cells in vitreous fluids showed lower expression of TLR2 and TLR9 in IOTB as compared to non-uveitis and non-TB uveitis groups. Next, peripheral CD4+ Teff cells of subjects with IOTB showed decreased proliferative responses and lower induction of Tregs following TLR2 and TLR9 stimulation. Further, TLR9 ligation resulted in increased IFN-γ and IL-17a but decreased expression of IL-10 and TGF-β. Lastly, lower expression of genes involved in TLR9 signalling after direct TLR9 ligation was observed in IOTB. Collectively, our results show that a subdued response to direct TLR2 and TLR9 stimulation in CD4+ T cells is associated with increased proinflammatory responses in IOTB. These findings reveal an important link between innate immune signalling and ensuing adaptive immune responses in IOTB with implications in other forms of extrapulmonary tuberculosis.

Ocular tuberculosis: Position paper on diagnosis and treatment management

Delay in diagnosis or treatment of ocular tuberculosis can result in loss of vision. However, due to the fact that early diagnosis is rarely achieved, there are still a broad variety of diagnostic and treatment approaches. Our aim was to reach a consensus on the management of diagnosis and treatment of ocular tuberculosis.

METHODS

Critical appraisal of the literature and expert opinion on diagnosis and treatment of ocular tuberculosis.

RESULTS AND CONCLUSION

The currently recommended method for ocular TB diagnosis is screening for tuberculosis in any uveitis of unknown etiology, recurrent or not responding to conventional therapy; in ocular findings highly suggestive of ocular TB and before immunosuppression (particularly biologic agents). TB screening in these cases includes tuberculosis skin testing and interferon gamma testing, along with complete medical history, ophthalmologic evaluation and chest imaging. Positively screened patients should be treated for active tuberculosis with 4 drugs (isoniazid, rifampicin, pyrazinamide and ethambutol) for 6-9 months. Patients should be reviewed at the end of the initiation phase (two months) and at the end of the overall treatment (6-9 months).

Anti-tubercular therapy for intraocular tuberculosis: A systematic review and meta-analysis

Intraocular tuberculosis remains a diagnostic and management conundrum for both ophthalmologists and pulmonologists. We analyze the efficacy and safety of anti-tubercular therapy (ATT) in patients with intraocular tuberculosis and factors associated with favorable outcome. Twenty-eight studies are included in this review, with a total of 1,917 patients. Nonrecurrence of inflammation was observed in pooled estimate of 84% of ATT-treated patients (95% CI 79-89). There was minimal difference in the outcome between patients treated with ATT alone (85% successful outcome; 95% CI 25-100) and those with concomitant systemic corticosteroid (82%; 95% CI 73-90). The use of ATT may be of benefit to patients with suspected intraocular tuberculosis; however, this conclusion is limited by the lack of control group analysis and standardized recruitment and treatment protocols. We propose further prospective studies to better establish the efficacy of ATT and ascertain the factors associated with favorable treatment outcomes.