Clinics of ocular tuberculosis: A review

Paradoxical Reaction in Intraocular Tuberculosis: Report of Three Cases

PURPOSE

To present paradoxical reaction (PR) in three cases with ocular tuberculosis (OTB) treated with antitubercular therapy (ATT), highlighting diagnostic challenges and treatment strategies.

METHODS

We retrospectively reviewed clinical records of three OTB patients presenting with paradoxical worsening after ATT initiation at two Brazilian university hospitals.

RESULTS

The patients (2 males, 1 female) experienced worsening clinical presentation (increased inflammation, vision loss) within two to three weeks after initiating ATT. One patient who was HIV-positive with unilateral multifocal choroiditis developed PR soon after starting antiretroviral therapy. The second patient presented with a choroidal tuberculoma in both eyes. The third patient also had multifocal choroiditis and developed a localized choroidal elevation with a double-layer sign as a manifestation of PR. All patients were maintained on ATT therapy in association with corticosteroids and experienced improvement of inflammatory signs.

CONCLUSION

This case series highlights the potential for PR in OTB patients. Close monitoring and prompt therapeutic adjustments are crucial for management success.

Epidemiology of Pediatric Uveitis

Uveitis is uncommon in children and its diagnosis and treatment are challenging. Little is known of the epidemiology of pediatric uveitis. Indeed, population-based studies in the literature are rare. However, there are many tertiary referral center reports that describe the patterns of uveitis in childhood, although few are from developed countries, and their comparison presents some issues. Anterior uveitis is the most frequent entity worldwide, especially in Western countries, where juvenile idiopathic arthritis is diffuse. Most cases of intermediate uveitis do not show any association with infectious or noninfectious systemic diseases. In low- and middle-income countries, posterior uveitis and panuveitis are prevalent due to the higher rates of infectious etiologies and systemic diseases such as Behçet disease and Vogt-Koyanagi-Harada disease. In recent decades, idiopathic uveitis rate has decreased thanks to diagnostic improvements.

Ophthalmic manifestations of tuberculosis

PURPOSE OF REVIEW

To evaluate the epidemiology, microbiology, and pathology of Mycobacterium Tuberculosis (MTB). Utilizing these basic science concepts, the reader will discover how MTB can cause disease in any part of ophthalmic system. This article will aid clinicians in establishing the difficult diagnosis and management strategies for ophthalmic tuberculosis (OTB).

RECENT FINDINGS

Recently, expert panels have reached a consensus on naming conventions and treatment strategies for the variety of ocular tuberculosis (TB). This consensus helps individual clinicians decide when to recommend full anti-TB treatment.

SUMMARY

Globally, TB is nearly ubiquitous in the human population. It is most recognized for its pulmonary disease, but pathology of nearly every structure of the ophthalmic system has been identified. This heterogeneity makes establishing a diagnosis difficult, but recent improvements in expert panel naming consensus and nucleic acid amplification tests are improving diagnostic abilities. Clinicians are now feeling more confident with prescribing anti-TB regimens, but ongoing questions regarding the use of oral steroids and risk of medication-induced ocular toxicity remain.

The immune response in tubercular uveitis and its implications for treatment: From anti-tubercular treatment to host-directed therapies

Tubercular uveitis (TB-uveitis) remains a conundrum in the uveitis field, which is mainly related to the diverse clinical phenotypes of TB-uveitis. Moreover, it remains difficult to differentiate whether Mycobacterium tuberculosis (Mtb) is present in the ocular tissues, elicits a heightened immune response without Mtb invasion in ocular tissues, or even induces an anti-retinal autoimmune response. Gaps in the immuno-pathological knowledge of TB-uveitis likely delay timely diagnosis and appropriate management. In the last decade, the immunopathophysiology of TB-uveitis and its clinical management, including experts' consensus to treat or not to treat certain conditions with anti-tubercular treatment (ATT), have been extensively investigated. In the meantime, research on TB treatment, in general, is shifting more toward host-directed therapies (HDT). Given the complexities of the host-Mtb interaction, enhancement of the host immune response is expected to boost the effectiveness of ATT and help overcome the rising burden of drug-resistant Mtb strains in the population. This review will summarize the current knowledge on the immunopathophysiology of TB-uveitis and recent advances in treatment modalities and outcomes of TB-uveitis, capturing results gathered from high- and low-burden TB countries with ATT as the mainstay of treatment. Moreover, we outline the recent progress of HDT development in the pulmonary TB field and discuss the possibility of its applicability to TB-uveitis. The concept of HDT might help direct future development of efficacious therapy for TB-uveitis, although more in-depth research on the immunoregulation of this disease is still necessary.

The Collaborative Ocular Tuberculosis Study (COTS) calculator-a consensus-based decision tool for initiating antitubercular therapy in ocular tuberculosis

OBJECTIVE

To introduce the Collaborative Ocular Tuberculosis Study (COTS) Calculator, an online clinical scoring system for initiating antitubercular therapy (ATT) in patients with ocular tuberculosis (TB).

METHOD

The COTS Calculator was derived from COTS Consensus (COTS CON) data, which has previously published consensus guidelines. Using a two-step Delphi method, 81 experts evaluated 486 clinical scenario-based questions, ranking their likelihood of initiating ATT in each specific scenario. Each scenario was a permutation of the results and/or availability of five following components-clinical phenotype, endemicity, two immunological (tuberculin skin test, interferon-γ release assay) and one radiological (chest X-Ray) test results-and a sixth component further stratifying three of the clinical phenotypes. The median scores and interquartile ranges (IQR) of each scenario were tabulated, representing the expert consensus on whether to initiate ATT in that scenario. The consensus table was encoded to develop the COTS Calculator.

RESULTS

The COTS Calculator can be accessed online at: https://www.oculartb.net/cots-calc . The attending physician can select the conditions present in the patient, which will generate a median score from 1 to 5. 114 out of 486 scenarios (24%) deliberated had a median score of 5 indicating expert consensus to initiate ATT.

CONCLUSION

The COTS Calculator is an efficient, low-cost, evidence and experience-based clinical tool to guide ATT initiation. While it holds substantial promise in improving standard-of-care for ocular-TB patients, future validation studies can help to as certain its clinical utility and reliability.

Anti-tubercular therapy in the treatment of tubercular uveitis: A systematic review and meta-analysis

We quantitatively evaluated the efficacy of antitubercular therapy (ATT) in tubercular uveitis (TBU) patients. Main outcome measures include inflammation recurrence, inflammation reduction, complete resolution of inflammation, improved visual acuity (VA), ability to taper corticosteroids to < 10 mg/day without inflammatory progression, and use of adjunctive immunosuppressants while on ATT. This review is prospectively registered in PROSPERO (CRD42020206845). Forty-nine studies reporting data for 4,017 TBU patients were included. In comparative studies, the odds ratio (OR) of inflammatory recurrence was 0.33 (95%CI:0.19-0.60) for TBU patients treated with ATT±corticosteroid versus no ATT. For TBU patients treated with ATT±corticosteroid, the pooled absolute incidences of inflammatory recurrence, inflammatory reduction, complete resolution of inflammation, and visual acuity improvement were 13% (n=310/2,216; 95%CI:9-18), 81% (n=217/276; 95%CI: 62-95), 83% (n=1,167/1,812; 95%CI: 77-89), and 65% (n=347/542; 95%CI:51-78), respectively. Corticosteroids were tapered to <10 mg/day without inflammatory progression in 91% (n=326/395; 95%CI:78-99) of patients, 9% (n=121/1,376; 95%CI:6-13) of whom were administered concomitant immunosuppressive agents alongside ATT. We conclude that treatment of TBU with ATT±corticosteroid is associated with a high level of control or improvement of inflammation. More prospective studies with detailed reporting of ATT regimens, patient subgroups, and outcomes are required to better evaluate ATT effectiveness.

Interferon-gamma release assay and chest X-ray to classify intraocular tuberculosis among clinically undifferentiated uveitis

BACKGROUND Tuberculosis (TB) is a common cause of intraocular inflammation in Indonesia. As no accurate biomarker can confirm the diagnosis, ophthalmologists often rely on systemic findings, such as tuberculin skin test, interferon-gamma release assay (IGRA), and chest X-ray (CXR) for TB suspicion. This study aimed to evaluate IGRA and CXR in classifying intraocular TB among patients with a clinically undifferentiated cause of uveitis. METHODS This cross-sectional study included 116 patients (a total of 163 affected eyes) with a clinically undifferentiated cause of uveitis. IGRA and CXR were performed as part of the workup. Data on visual acuity, anterior chamber inflammation grade, and anatomical classification of uveitis were recorded. As there were no confirmed ocular tuberculosis (OTB) in our cases, eyes were classified into probable OTB, possible OTB, and unclassified. RESULTS Overall, 93 patients (80.2%) with a clinically undifferentiated cause of uveitis had positive IGRA, whereas 10 (8.6%) had CXR results suggestive of TB. More than one-third of the patients were blind (visual acuity <3/60), and panuveitis was the commonest anatomical classification. A trend was identified in patients with panuveitis, who often showed ≥2+ cell anterior chamber inflammation (p for trend = 0.023), according to OTB criteria (probable OTB = 3/4, 75.0%; possible OTB = 44/67, 65.7%; unclassified = 2/9, 22.2%). Furthermore, the clinically undifferentiated uveitis cases were eligible to be stratified into probable (8.6%) and possible (75.0%) OTB categories after IGRA and CXR examinations. CONCLUSIONS The combination of IGRA and CXR is valuable for classifying and diagnosing TB-related uveitis. A multidisciplinary approach is essential when the cause of uveitis is unknown.

Colombian ocular infectious epidemiology study (COIES): presumed ocular tuberculosis incidence and sociodemographic characterization, 2015-2020

PURPOSE

This study aims to describe the incidence and geographical distribution of presumed ocular tuberculosis (POTB) in Colombia between 2015 and 2020 based on the Colombian Ministry of Health and Social Protection data.

METHODS

We conducted a claims-based study using the Integrated Social Protection Information System database from the Colombian Ministry of Health. We used the specific code of the International Classification of Diseases for Ocular Tuberculosis (A18.5) and tuberculosis from 2015 to 2020 to estimate the incidence and the demographic status of the disease in Colombia. We used STROBE guidelines.

RESULTS

During the 6 years of study, the crude unadjusted incidence was 0.2 new cases of POTB in one million consulting patients and 55 new cases of POTB in 100,000 patients with TB showing a decreasing pattern of the disease. From the 28 new cases, the mean age of presentation was 41.4 years (SD ± 25.3) with a female predominance (60.7% of the cases). Distribution by age shows a higher proportion of cases in groups 15-19 (14%), 20-24 (11%), 55-59 (11%), and 60-64 (11%) years of age. The geographic analysis showed a higher number of cases in Andean region, followed by the Caribbean and Pacific regions.

CONCLUSIONS

This is the first study that determines the incidence of POTB in a developing country from Latin America. POTB incidence in Colombia is lower than the reported worldwide. It could be attributed to a low burden of Tuberculosis in Colombia, underdiagnosis, and a low rate of immigration from countries with a high burden of TB.

Infectious Posterior Uveitis - Toxoplasmosis, Treponema, Tuberculosis (TTT)

Toxoplasma gondii, Treponema pallidum and Mycobacterium tuberculosis are the most important infectious causes of posterior uveitis. The epidemiology, clinical picture, diagnostic and treatment strategies of these diseases are presented.

Tubercular Retinal Vasculitis: Diagnostic Dilemma and Management Strategies

Ocular tuberculosis (OTB) is a rare, extrapulmonary manifestation of systemic TB, which has been a global etiology of uveitis for centuries, though concentrated in the developing world. OTB remains difficult to diagnose clinically despite a plethora of conventional and modern investigations. Tubercular retinal vasculitis (TRV) is a common and specific presentation of OTB but is variably defined in the literature in terms of clinical profile and the investigations essential for diagnosis and treatment. Ironically, the need and duration of antitubercular treatment is uncertain for this manifestation of ocular TB. The rationale and utility for corticosteroids is similarly equivocal for TRV. This review attempts to tease out a commonsense approach from the best available evidence and consensus in the literature to suspect, investigate and diagnose TRV with reasonable certainty, and institute appropriate treatment with due ethnic and geographic considerations.

Characterization of M Cells in Tear Duct-Associated Lymphoid Tissue of Mice: A Potential Role in Immunosurveillance on the Ocular Surface

The ocular mucosal tissues are exposed to potentially harmful foreign antigens in the air and tear fluid. The tear duct-associated lymphoid tissue (TALT) may contribute to immune surveillance in the eye region. Follicle-associated epithelium (FAE) of TALTs is classified as stratified squamous epithelium and consists of squamous epithelial cells arranged in layers on the basement membrane. In contrast, most mucosa-associated lymphoid tissue is covered by a monolayer of epithelium containing microfold (M) cells. Therefore, antigen uptake and the presence of M cells in TALT are not fully understood. The present study found that a small population of FAE cells in the TALT expressed intestinal M-cell markers, namely Sox8, Tnfaip2, GP2, and OPG. This cell population was identified as functional M cells because of their uptake capacity of luminal nanoparticles. In addition, RANKL, which is essential for M-cell differentiation, was expressed by stroma-like cells at the subepithelial region and its receptor RANK by the FAE in the TALT. The administration of RANKL markedly increased the number of Sox8⁺ M cells. In contrast, deficiency in OPG, an endogenous inhibitor of RANKL, increased the number of M cells in the TALT. These data demonstrate that the RANKL-RANK axis is essential for M-cell differentiation in the TALT. Furthermore, immunization via eye drops elicited the production of antigen-specific antibodies in tears, which was enhanced by RANKL administration. Thus, TALT M cells play an important role in the immunosurveillance of the eye region.

Optic neuritis classification in 2021

Optic neuritis (ON) can be associated with inflammatory disease of the central nervous system or can be isolated, with or without relapse. It can also be associated with infectious or systemic disease. These multiple associations based on a variety of clinical, radiological, and biological criteria that have changed over time have led to overlapping phenotypes: a single ON case can be classified in several ways simultaneously or over time. As early, intensive treatment is often required, its diagnosis should be rapid and precise. In this review, we present the current state of knowledge about diagnostic criteria for ON aetiologies in adults and children, we discuss overlapping phenotypes, and we propose a homogeneous classification scheme. Even if distinctions between typical and atypical ON are relevant, their phenotypes are largely overlapping, and clinical criteria are neither sensitive enough, nor specific enough, to assure a diagnosis. For initial cases of ON, clinicians should perform contrast enhanced MRI of the brain and orbits, cerebral spinal fluid analysis, and biological analyses to exclude secondary infectious or inflammatory ON. Systematic screening for MOG-IgG and AQP4-IgG IgG is recommended in children but is still a matter of debate in adults. Early recognition of neuromyelitis optica spectrum disorder, MOG-IgG-associated disorder, and chronic relapsing idiopathic optic neuritis is required, as these diagnoses require therapies for relapse prevention that are different from those used to treat multiple sclerosis.

Extrapulmonary Tuberculosis—An Update on the Diagnosis, Treatment and Drug Resistance

Pathogenic Mycobacterium tuberculosis complex organisms (MTBC) primarily cause pulmonary tuberculosis (PTB); however, MTBC are also capable of causing disease in extrapulmonary (EP) organs, which pose a significant threat to human health worldwide. Extrapulmonary tuberculosis (EPTB) accounts for about 20–30% of all active TB cases and affects mainly children and adults with compromised immune systems. EPTB can occur through hematogenous, lymphatic, or localized bacillary dissemination from a primary source, such as PTB, and affects the brain, eye, mouth, tongue, lymph nodes of neck, spine, bones, muscles, skin, pleura, pericardium, gastrointestinal, peritoneum, and the genitourinary system as primary and/or disseminated disease. EPTB diagnosis involves clinical, radiological, microbiological, histopathological, biochemical/immunological, and molecular methods. However, only culture and molecular techniques are considered confirmatory to differentiate MTBC from any non-tuberculous mycobacteria (NTM) species. While EPTB due to MTBC responds to first-line anti-TB drugs (ATD), drug susceptibility profiling is an essential criterion for addressing drug-resistant EPTB cases (DR-EPTB). Besides antibiotics, adjuvant therapy with corticosteroids has also been used to treat specific EPTB cases. Occasionally, surgical intervention is recommended, mainly when organ damage is debilitating to the patient. Recent epidemiological studies show a striking increase in DR-EPTB cases ranging from 10–15% across various reports. As a neglected disease, significant developments in rapid and accurate diagnosis and better therapeutic interventions are urgently needed to control the emerging EPTB situation globally. In this review, we discuss the recent advances in the clinical diagnosis, treatment, and drug resistance of EPTB.