Ocular tuberculosis: Where are we today?

Rare bilateral corneoscleral perforation secondary to ocular tuberculosis: a case report and clinical insights

BACKGROUND

This case represents a rare presentation of bilateral corneoscleral perforation secondary to presumed ocular mycobacterium tuberculosis infection with the goal of reporting a case of bilateral corneoscleral perforation in the setting of a positive interferon-γ release assay (IGRA) test.

FINDINGS

A 27-year-old patient presented with five months of redness, worsening eye pain, and five days of decreasing vision. Visual acuity (VA) was counting fingers bilaterally. Intraocular pressure (IOP) was 10 mmHg and 19 mmHg in the right and left eye, respectively. A slit lamp examination disclosed conjunctival injection, corneal haze, bilateral mutton-fat keratic precipitates, and a hypopyon in both eyes. The right eye had a 1.5 mm × 1.5 mm Seidel-positive corneal perforation with uveal prolapse. Similarly, the left eye had a 0.5 mm × 0.5 mm Seidel-negative inferior corneal perforation with uveal plugging. The chest X-ray showed a left-sided pleural effusion.

CONCLUSION

Computed tomography (CT) of the face and sinuses showed bilateral circumferential globe thickening. IGRA was positive. All other rheumatologic and infectious workups were negative, including HIV, ACE, ANA, ANCA, CRP, anti-scleroderma antibody and HCV. The patient was treated with intravenous methylprednisolone and seven months of rifampin, isoniazid, pyrazinamide, and ethambutol. This workup shows the rare bilateral corneal involvement of ocular tuberculosis.

Validation of the Online Collaborative Ocular Tuberculosis Study Calculator for Tubercular Uveitis

Importance

This was the first study, to the authors' knowledge, to statistically evaluate the predictive accuracy of Collaborative Ocular Tuberculosis Study (COTS) calculator in guiding initiation of antitubercular therapy (ATT) in patients with clinically suspicious tubercular uveitis (TBU) in an international cohort.

Objective

To evaluate the accuracy of a score of 4 or greater on the online COTS calculator in recommending ATT initiation.

Design, Setting, and Participants

This study was an evaluation of a diagnostic test or technology. Data input required for the COTS calculator were extracted from the COTS-1 study dataset, which comprised retrospective, observational records of patients with TBU who were monitored for 12 months after treatment. Patients were recruited from international ophthalmic centers. In the absence of a traditional criterion standard, the 12-month treatment response to ATT was used to classify patients as disease positive or negative. The accuracy of clinicians at the ATT decision-making stage in the COTS-1 study was set against COTS calculator scores of 4 or greater. Diagnostic accuracy metrics, including sensitivity, specificity, positive predictive value (PPV), precision, recall, and F1 score, were computed. Data collected from January 2004 to December 2014 were analyzed.

Exposures

COTS calculator to guide initiation of ATT in patients with TBU.

Main Outcomes and Measures

Comparison of accuracy between clinician judgment and the COTS calculator, analyzed at varying scores and further stratified by tuberculosis endemicity.

Results

Of the 492 participants (mean [SD] age, 42.3 [19.0] years; 233 male [47.3%]), application of the COTS calculator identified 225 (45.7%) with high or very high probability to start ATT (score = 4 or 5) and 111 (22.5%) with very high probability alone (score = 5). COTS-5 exhibited the highest specificity (88.7%; 95% CI, 81.4%-93.8%) compared with clinician judgment (29.6%; 95% CI, 21.4%-38.8%), and clinician judgment led in sensitivity (95.5%; 95% CI, 92.9%-97.4%) compared with COTS-5 (26%; 95% CI, 21.6%-30.7%). COTS-4 and COTS-5 balanced specificity (64.3%; 95% CI, 54.9%-73.1%) and sensitivity (48.8%; 95% CI, 43.7%-54%). PPV and sensitivity were consistently higher in the endemic group for all 3 tests.

Conclusions and Relevance

Results of this diagnostic study suggest that the COTS calculator (score ≥4) was more specific than clinician judgment for ATT initiation. Although clinician judgment is a good first step to identify all potential true positives (with high sensitivity), a second consultation with COTS-5 (with high PPV) may lead to less false positives. This tool, apt for high-prevalence, low-resource settings, recommends ATT more selectively for genuine TBU cases. Large prospective studies are essential to explore potential improvements in the calculator's sensitivity.

The Role of Corticosteroids and Immunomodulatory Therapy in the Management of Infectious Uveitis

PURPOSE

The index review aims to provide an update on the role of corticosteroids and steroid-sparing immunomodulatory therapy (IMT) in managing patients with infectious uveitis.

METHOD

Narrative literature review.

RESULTS

Corticosteroids and immunomodulatory therapy (IMT) focus on the host defense system instead of the pathogen, adjusting exaggerated inflammatory reactions to reduce potential harm to ocular tissues. Systemic or local corticosteroids are primarily selected as adjunctive medication for infectious uveitis. Concomitant corticosteroids have also been used in cases of paradoxical worsening in ocular tuberculosis and immune recovery uveitis in cytomegalovirus (CMV) retinitis. While there is no well-established evidence to support the use of IMT in infectious uveitis, it is occasionally used in clinical settings to treat persistent inflammation following resolution of infection such as cases of ocular tuberculosis and ocular syphilis where an insufficient response is observed with corticosteroids.

CONCLUSION

There is no consensus on the position of immunomodulatory therapy in the management of infectious uveitis with different etiologies. The index review provides an overview of available adjunctive corticosteroids and IMT options to assist clinicians in managing such disease entities more efficiently.

Peripheral ulcerative keratitis secondary to tuberculosis: A case report and literature review

RATIONALE

Compared with intraocular tuberculosis, ocular tuberculosis with ocular surface involvement is rare. Corneal involvement in ocular tuberculosis may include interstitial keratitis or peripheral ulcerative keratitis. We report a case of peripheral ulcerative keratitis directly caused by tuberculosis.

PATIENT CONCERNS

A 20-year-old man complained of vision loss and pain in the left eye that had lasted for 1 week. A slit lamp examination of the left eye showed a corneal epithelial defect, interstitial corneal edema, and a white irregular infiltrative lesion and ulcer (with the dimension of 2 × 2.5 mm) in the inferior temporal region.

DIAGNOSES

The corneal ulcer was scraped, and the Mycobacterium tuberculosis deoxyribonucleic acid polymerase chain reaction was positive.

INTERVENTIONS AND OUTCOMES

After a month of oral antituberculosis treatment, the corneal ulcer resolved, and the intraocular inflammation improved.

LESSONS

Peripheral ulcerative keratitis secondary to tuberculosis can be directly caused by M tuberculosis.

Diagnosis and Treatment of Uveitis in Children: A Summary of the Latest Data from a 5-Year Literature Review (2018-2023)

Pediatric uveitis has a low incidence. It is very diverse in its presentation and is often the first sign of a severe systemic disease. The pediatric population poses a special therapeutic and diagnostic challenge due to the potentially adverse effects of therapeutic agents on the young body and difficult cooperation with the patient during the examination, as well as the increased risk of complications that can lead to severe disability. The most commonly diagnosed type of uveitis is non-infectious, with first-line therapy consisting of systemic corticosteroids followed by disease-modifying drugs (methotrexate (MTX), mycophenolate mofetil (MMF), and cyclosporin A (CsA)). In severe, refractory cases, biologic therapy is used. The authors reviewed the current literature on the etiology, diagnostic tools, and treatment of uveitis in the pediatric population covering the years 2018-2023, presenting current methods of modern diagnosis and treatment. The reason for writing this article was the need to update the knowledge on uveitis, driven by the increasing prevalence of autoimmune uveitis in the pediatric population. This trend presents significant challenges in diagnosing and treating the disease, as well as managing its complications. Correctly identifying the pathogenetic factor of uveitis can facilitate the diagnosis of the systemic disease underlying the ocular infection and enable the timely implementation of systemic treatment. Furthermore, the emergence of new diagnostic methods necessitates a revision and update of ophthalmic knowledge, essential for both ophthalmologists and other specialists involved in the treatment of uveitis.

Clinical Insights: Antimicrobial Therapy for Infectious Uveitis

Infectious uveitis is a major global cause of vision impairment. Despite the eye's immune privilege, afforded by the blood-ocular barrier that restricts microbial entry, several pathogens such as bacteria, viruses, fungi, and parasites can still infiltrate and cause ocular infections and complications. Clinicians often encounter significant challenges in treating infectious uveitis due to limited or ineffective treatment options. Modern molecular techniques and imaging can aid in diagnosing and assessing intraocular infections. Various antimicrobial therapies exist, spanning topical and systemic treatments, but these are constrained by issues like drug concentration, penetration, effective duration, toxicity, and side effects. Treatment approaches also differ based on the infection's etiology. This review provides recent updates on antimicrobial therapies from a clinical perspective, covering topical, systemic, and regional treatments for infectious uveitis.

Characteristics and outcomes of the duration of treatment with adjunctive corticosteroids in intraocular tuberculosis

Introduction

Intraocular tuberculosis (IOTB) is a common site of extrapulmonary tuberculosis and a main cause of infectious uveitis. It can result in severe visual morbidity if not recognized and treated properly. The clinical manifestations of IOTB are varied, and the duration of treatment is unclear. This study describes the clinical characteristics and outcomes of patients with IOTB and compares the duration of antituberculosis therapy (ATT) and steroid use.

Method

An 8-year retrospective study of IOTB patients in an endemic area of a tertiary hospital in Thailand. All patients had a complete treatment of ATT at least for 6 months.

Results

Forty-three patients with 57 eyes and a mean age of 43.72 years were included. Panuveitis (38.6 %), retinal phlebitis (31.6 %), and posterior uveitis (15.8 %) were common clinical characteristics. A significant difference between initial and final best corrected visual acuity (BCVA) after ATT in 6 months for therapy and at least 9 months for therapy was observed (p = 0.004, 0.003, respectively). Ninety point nine percent of patients who received ATT for 9 months achieved a successful treatment outcome, while 66.7 % of patients who received ATT for 6 months did (p = 0.056). Patients who received systemic and/or regional corticosteroids therapy during treatment had a higher rate of treatment failure (p < 0.001).

Conclusion

IOTB had a variety of clinical manifestations, including nongranulomatous inflammation. Patients who completed treatment with ATT for at least 6 months improved their final BCVA. There was no difference in treatment outcomes regarding the duration of treatment. Combined treatment with systemic and/or regional corticosteroids was significantly associated with failed treatment outcomes.

Causes of infectious pediatric uveitis: A review

Infectious pediatric uveitis is a rare disease that can cause severe ocular damage if not detected rapidly and treated properly. Additionally, early identification of an infection can protect the child from life-threatening systemic infection. Infectious uveitis can be congenital or acquired and may manifest as a primary ocular infection or as a reactivation. Nevertheless, publications on infectious paediatric uveitis are usually limited to a small number of patients or a case report. So far, most studies on uveitis in children have focused primarily on noninfectious uveitis, and a systematic study on infectious uveitis is lacking. In this review, we summarize the literature on infectious uveitis in pediatric populations and report on the epidemiology, pathophysiology, clinical signs, diagnostic tests, and treatment. We will describe the different possible pathogens causing uveitis in childhood by microbiological group (i.e. parasites, viruses, bacteria, and fungi). We aim to contribute to early diagnosis and management of infectious pediatric uveitis, which in turn might improve not only visual outcome, but also the general health outcome.

Clinical manifestation and long-term follow-up of presumed ocular tuberculosis in China

Background

This study aimed to report the clinical manifestations of presumed ocular tuberculosis (OTB) and the treatment response after anti-tuberculosis therapy (ATT) in a Chinese population.

Methods

Clinical data, including general characteristics, ocular lesions, visual acuity at baseline, and final follow-up of patients with presumed OTB from 2006 to 2022 in two eye clinics in China, were retrospectively analyzed.

Results

The study included 84 eyes of 52 patients. The following ocular manifestations were observed: anterior uveitis (4.8%), posterior uveitis (34.5%), panuveitis (11.9%), retinal vasculitis (40.5%) and optic neuropathy (8.3%). After ATT, the vision improved by varying degrees in 48 eyes (57.1%), remained stable in 34 eyes (40.5%) and decreased in 2 eyes (2.4%).

Conclusions

OTB is likely to be misdiagnosed as other infectious uveitis and optic neuropathy. Clinical features must be interpreted in conjunction with topical and general laboratory findings and in collaboration with other subspecialties to make a final diagnosis.

Berlin nodules: About 3 cases

INTRODUCTION

Granulomatous uveitis is mainly defined by the nature of keratic precipitates and iris nodules. Anterior chamber (AC) granulomas, also known as Berlin nodules (BN), are circumscribed granulomatous nodules that form in the iridocorneal angle (ICA) in response to intraocular inflammation.

CASES DESCRIPTION

We present three representative cases of anterior uveitis with berlin nodules to insist on the clinical features of this entity. Case 1: A female adult was referred to our department for bilateral redness and gradual blurry vision. Slit-lamp examination of both eyes (OU) found a yellow-white nodular mass at 6 o'clock on the peripheral iris with irido-crystalline synechiae, vitreous haze and blurred fundus. Purified protein derivative skin test revealed an induration of 20 mm. A diagnosis of presumed ocular tuberculosis was made. The patient received antituberculosis drugs and steroids with good evolution. Case 2: An 11-year-old girl presented for redness and pain OU. Anterior segment examination showed circumciliary congestion, epithelial microcystic edema OU and pearly vascularized lesion against the cornea in the right eye. Fundus examination was unremarkable. A diagnosis of definite ocular sarcoidosis was made based on accessory salivary glands biopsy. The patient was treated with teroids and controlled twice a week. Case 3: A 26-year-old male presented with a redness and pain of the left eye. The slit-lamp examination showed fine keratic precipitates with pearly white nodules within the AC. Fundus examination showed a chorioretinal lesion and occlusive vasculitis. Chest CT was consistent with milliary tuberculosis. Adequate therapy was initiated with favorable outcome.

CONCLUSION

BN can be associated with various ocular manifestations of several diseases. They may be the first manifestation of systemic conditions and seem to be well managed with topical steroids.

Detection of microRNAs expression signatures in vitreous humor of intraocular tuberculosis

BACKGROUND

MicroRNA (miRNA) expression analysis has been shown to provide them as biomarkers in several eye diseases and has a regulatory role in pathogenesis. However, miRNA expression analysis in the vitreous humor (VH) of intraocular tuberculosis (IOTB) is not studied. Thus, we aim to find miRNA expression signatures in the VH of IOTB patients to identify their regulatory role in disease pathogenesis and to find them as potential biomarkers for IOTB.

METHODS AND RESULTS

First, we profiled miRNAs in VH of three IOTB and three Macular hole (MH) samples as controls through small-RNA deep sequencing using Illumina Platform. In-house bioinformatics analysis identified 81 dysregulated miRNAs in IOTB. Further validation in VH of IOTB (n = 15) compared to MH (n = 15) using Real-Time quantitative PCR (RT-qPCR) identified three significantly upregulated miRNAs, hsa-miR-150-5p, hsa-miR-26b-5p, and hsa-miR-21-5p. Based on the miRNA target prediction, functional network analysis, and RT-qPCR analysis of target genes, the three miRNAs downregulating WNT5A, PRKCA, MAP3K7, IL7, TGFB2, IL1A, PRKCB, TNFA, and TP53 genes involving MAPK signaling pathway, PI3K-AKT signaling pathway, WNT signaling pathway, Cell cycle, TGF-beta signaling pathway, Long-term potentiation, and Sphingolipid signaling pathways, have a potential role in disease pathogenesis. The ROC analysis of RT-qPCR data showed that hsa-miR-150-5p with AUC = 0.715, hsa-miR-21-5p with AUC = 0.789, and hsa-miR-26b-5p with AUC = 0.738; however, the combination of hsa-miR-21-5p and hsa-miR-26b-5p with AUC = 0.796 could serve as a potential biomarker for IOTB.

CONCLUSIONS

This study provides the first report on miRNA expression signatures detected in VH for IOTB pathogenesis and also provides a potential biomarker for IOTB.

The Neuro-Ophthalmology of Tuberculosis

Tuberculosis (TB) is a global health concern and central nervous system (CNS) TB leads to high mortality and morbidity. CNS TB can manifest as tubercular meningitis, tuberculoma, myelitis, and arachnoiditis. Neuro-ophthalmological involvement by TB can lead to permanent blindness, ocular nerve palsies and gaze restriction. Visual impairment is a dreaded complication of tubercular meningitis (TBM), which can result from visual pathway involvement at different levels with varying pathogenesis. Efferent pathway involvement includes cranial nerve palsies and disorders of gaze. The purpose of this review is to outline the various neuro-ophthalmological manifestations of TB along with a description of their unique pathogenesis and management. Optochiasmatic arachnoiditis and tuberculomas are the most common causes of vision loss followed by chronic papilloedema. Abducens nerve palsy is the most commonly seen ocular nerve palsy in TBM. Gaze palsies with deficits in saccades and pursuits can occur due to brainstem tuberculomas. Corticosteroids are the cornerstone in the management of paradoxical reactions, but other immunomodulators such as thalidomide and infliximab are being explored. Toxic optic neuropathy caused by ethambutol necessitates careful monitoring and immediate drug discontinuation. Cerebrospinal fluid diversion through ventriculo-peritoneal shunting may be required in patients with hydrocephalus in stage I and II of TBM to prevent visual impairment. Early diagnosis and prompt management are crucial to prevent permanent disability. Prevention strategies, public health initiatives, regular follow-up and timely intervention are essential in reducing the burden of CNS TB and its neuro-ophthalmological complications.

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.

Ocular Tuberculosis in Pediatrics: A Case Report

A 17-year-old male was taken to the emergency department for decreased left visual acuity and floaters beginning that same day. There was a history of exposure to pulmonary tuberculosis five years before (mother as index case) followed by a four-month period of isoniazid prophylaxis. The ophthalmic examination showed posterior and intermediate uveitis in the left eye. Laboratory tests were normal; IgG for herpes simplex 1 was positive and both the varicella-zoster virus and remaining serologic tests were negative. Chest radiography was normal. Two weeks later, an epiretinal membrane with risk of tractional retinal detachment was observed. The Mantoux tuberculin skin test showed an induration of 15 mm and the IGRA test was positive. Sputum and vitreous humor samples were collected. Quadruple therapy and prednisolone were started. Ten days later, a posterior vitreous detachment with underlying vitreous hematoma was observed. Posterior vitrectomy and peripheral endolaser were performed without complications. One month later, the microbiological results became available, with the identification of Mycobacterium tuberculosis. Corticosteroids were weaned progressively. Antituberculous drugs were maintained for six months. The patient made a full recovery.

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.

Presumed tuberculosis-related scleritis

AIMS

To evaluate the clinical characteristics and therapeutic outcome of patients with recurrent scleritis of unknown demonstrable aetiology and positive QuantiFERON-TB Gold In-Tube test (QFT).

METHODS

Retrospective chart review of the demographic, clinical, laboratory and therapeutic outcome data of 15 patients. Clinical characteristics as well as remission rate after standard antituberculous therapy (ATT) were assessed.

RESULTS

There were 9 men and 6 women with a mean age of 48.9 years (range, 32-73). Scleritis was diffuse in 10 patients (66.6%) and nodular in 5 patients (33.3%), 1 of them with concomitant posterior scleritis. It was bilateral in 7 patients (46.6%) and recurrent in all of them. Scleritis appeared after prior uveitis (10 patients, 66.6%) and/or with concomitant uveitis (5 patients, 33.3%) or peripheral keratitis (5 patients, 33.3%). Previous ocular surgery was found in 7 patients (46.6%). Previous extraocular tuberculosis (TB) infection or previous TB contact was detected in 11 patients (73.3%). No radiologic findings of active extraocular TB were detected. ATT was used in 15 patients, sometimes with the addition of systemic corticosteroids (5 patients) and methotrexate (1 patient); 14 patients achieved complete remission (93.3%).

CONCLUSION

Presumed TB-related scleritis may appear in recurrent scleritis of unknown origin and positive QFT. It may occur after prior uveitis and/or concomitantly with uveitis or peripheral keratitis, and it may be triggered by previous ocular surgery. No patients had evidence of concurrent active extraocular infection, although many had previous TB infection or TB contact. ATT was effective, sometimes with the addition of systemic corticosteroids and methotrexate.

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.

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.

Interferon-gamma release assays in tuberculous uveitis: a comprehensive review

Tuberculous uveitis (TBU) comprises a broad clinical spectrum of ocular manifestations, making its diagnosis challenging. Ophthalmologists usually require evidence from investigations to confirm or support a clinical diagnosis of TBU. Since direct isolation of the causative organism from ocular specimens has limitations owing to the small volume of the ocular specimens, resultant test positivities are low in yield. Immunodiagnostic tests, including the tuberculin skin test and interferon-gamma release assays (IGRAs), can help support a clinical diagnosis of TBU. Unlike the tuberculin skin test, IGRAs are in vitro tests that require a single visit and are not affected by prior Bacillus Calmette-Guerin vaccination. Currently, available IGRAs consist of different techniques and interpretation methods. Moreover, newer generations have been developed to improve the sensitivity and ability to detect active tuberculosis. This narrative review collates salient practice points as a reference for general ophthalmologists, such as evidence for the utilization of IGRAs in patients with suspected TBU, and summarizes basic knowledge and details of clinical applications of these tests in a clinical setting.

Automated lesion segmentation and quantification for prediction of paradoxical worsening in patients with tubercular serpiginous-like choroiditis

To develop and evaluate a fully automated pipeline that analyzes color fundus images in patients with tubercular serpiginous-like choroiditis (TB SLC) for prediction of paradoxical worsening (PW). In this retrospective study, patients with TB SLC with a follow-up of 9 months after initiation of anti-tubercular therapy were included. A fully automated custom-designed pipeline was developed which was initially tested using 12 baseline color fundus photographs for assessment of repeatability. After confirming reliability using Bland–Altman plots and intraclass correlation coefficient (ICC), the pipeline was deployed for all patients. The images were preprocessed to exclude the optic nerve from the fundus photo using a single-shot trainable WEKA segmentation algorithm. Two automatic thresholding algorithms were applied, and quantitative metrics were generated. These metrics were compared between PW + and PW- groups using non-parametric tests. A logistic regression model was used to predict probability of PW for assessing binary classification performance and receiver operator curves were generated to choose a sensitivity-optimized threshold. The study included 139 patients (139 eyes; 92 males and 47 females; mean age: 44.8 ± 11.3 years) with TB SLC. Pilot analysis of 12 images showed an excellent ICC for measuring the mean area, intensity, and integrated pixel intensity (all ICC > 0.89). The PW + group had significantly higher mean lesion area (p = 0.0152), mean pixel intensity (p = 0.0181), and integrated pixel intensity (p < 0.0001) compared to the PW- group. Using a sensitivity optimized threshold cut-off for mean pixel intensity, an area under the curve of 0.87 was achieved (sensitivity: 96.80% and specificity: 72.09%). Automated calculation of lesion metrics such as mean pixel intensity and segmented area in TB SLC is a novel approach with good repeatability in predicting PW during the follow-up.

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 Episcleritis: A Review of Literature

Episcleritis is rarely reported to be associated with tuberculosis (TB). In this review, we highlight this underreported entity and elaborate on the natural history of the reported cases in the literature. Eighteen articles were found to describe numerous cases throughout the past century. Forty patients diagnosed with tuberculous episcleritis were found in the literature. The majority of the patients presented with a latent form of TB and fewer cases were linked with active/pulmonary disease. The natural history of episcleritis was found to have chronic and recurrent attacks refractory to traditional treatment, and the most commonly reported type was the nodular form. The described cases were eventually treated by quadruple antituberculous therapy, and fortunately, recurrence after treatment completion was not documented. It is imperative to highlight such entities that may be underreported in endemic countries, as successful therapy would decrease ocular morbidity and prevent potential unforeseen tuberculous complications.

Differences between Mycobacterium chimaera and tuberculosis Using Ocular Multimodal Imaging: A Systematic Review

Due to their non-specific diagnostic patterns of ocular infection, differential diagnosis between Mycobacterium (M.) chimaera and tuberculosis can be challenging. In both disorders, ocular manifestation can be the first sign of a systemic infection, and a delayed diagnosis might reduce the response to treatment leading to negative outcomes. Thus, it becomes imperative to distinguish chorioretinal lesions associated with M. chimaera, from lesions due to M. tuberculosis and other infectious disorders. To date, multimodal non-invasive imaging modalities that include ultra-wide field fundus photography, fluorescein and indocyanine green angiography, optical coherence tomography and optical coherence tomography angiography, facilitate in vivo examination of retinal and choroidal tissues, enabling early diagnosis, monitoring treatment response, and relapse detection. This approach is crucial to differentiate between active and inactive ocular disease, and guides clinicians in their decisional-tree during the patients’ follow-up. In this review, we summarized and compared the available literature on multimodal imaging data of M. chimaera infection and tuberculosis, emphasizing similarities and differences in imaging patterns between these two entities and highlighting the relevance of multimodal imaging in the management of the infections.

Dysregulated expression of microRNAs in aqueous humor from intraocular tuberculosis patients

BACKGROUND

Systemic Mycobacterium tuberculosis (Mtb) infection alters microRNA's expression that controls cellular processes and modulates host defense mechanisms. However, the role of miRNAs in intraocular tuberculosis (IOTB) remains unknown. Therefore, this study aims to identify dysregulated miRNAs in the aqueous humor (AH) of patients with IOTB.

METHODS

AH from intraocular tuberculosis patients (n = 2) and cataract controls (n = 2) were used for small RNA deep sequencing using HiSeq Illumina sequencing platform. Differentially expressed miRNAs and their targets were identified by the bioinformatics approach, and their regulatory functions were predicted by pathway enrichment analysis. The expression of selected miRNAs and their binding targets were further validated by real-time quantitative PCR (RT-qPCR).

RESULTS

In total, we identified 56 differentially expressed miRNAs in the AH of intraocular tuberculosis (IOTB) patients compared to controls. We selected four significantly dysregulated miRNAs (miR-423-5p, miR-328-3p, miR-21-5p, and miR-16-5p) based on the RT-qPCR validation and predicted their gene targets. We developed a miRNA-targets regulatory network by combining pathways of interest and genes associated with TB. We identified that these four miRNAs might play an important role in IOTB pathogenesis via tuberculosis-associated pathways; PI3K-Akt signaling, autophagy and MAPK pathway.

CONCLUSIONS

For the first time, this study identifies the dysregulation of four miRNAs in the AH of IOTB patients using the ultra-low input small-RNA sequencing approach. Further target prediction and validation identify the role of these miRNAs in tuberculosis pathogenesis via tuberculosis-related pathways. This study identifies miRNAs as potentially ideal biomarkers in the aqueous humor of IOTB patients.

The diagnostic value of polymerase chain reaction for ocular tuberculosis diagnosis in relation to antitubercular therapy response: a meta-analysis

BACKGROUND

Polymerase chain reaction (PCR) is currently considered the method of choice for diagnosing ocular tuberculosis. However, the sensitivity and specificity of PCR using ocular samples remain uncertain. Our meta-analysis aimed to review the diagnostic accuracy of PCR testing in confirming ocular tuberculosis, with responses to antitubercular therapy (ATT) as reference indices.

METHODS

A systematic literature search of the PubMed, EBSCOHost, Scopus, and Google Scholar databases was performed using the standardized PRISMA guideline. Observational studies reporting both PCR MTb positivity and ATT response were included. Meta-analysis was performed to estimate the pooled positivity rate, sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratios (DOR), and summary receiver operating curves (SROC).

RESULTS

The pooled positivity rate for PCR MTb was 0.55 (95% CI 0.44-0.67). The overall sensitivity and specificity were 88% (95% CI 83-92) and 71% (95% CI 60-80), respectively. The pooled DOR was 12.15 (95% CI 5.55-26.62). The area under the SROC was 0.83.

CONCLUSIONS

The diagnostic accuracy of PCR Mtb is not sufficient for use as a benchmark for ocular TB diagnosis routinely based on ATT response. A negative result may help avoid prescribing unnecessary ATT in dilemmatic cases.

A Novel Pathogenic NOD2 Variant in a Mother and Daughter with Blau Syndrome

BACKGROUND

Blau syndrome (BS) is a rare dominantly-inherited autoinflammatory disorder characterized by the triad of arthritis, uveitis and dermatitis that is consequence of gain-of-function NOD2 mutations. We describe the clinical features and genetic basis of a family with two affected members in consecutive generations affected with childhood onset arthritis and uveitis.

MATERIALS AND METHODS

Clinical features were retrospectively collected from clinical records. Genetic studies were performed using the Sanger method of DNA sequencing.

RESULTS

The proband is a 44 years-old female, who was diagnosed with juvenile onset arthritis at the age of 9 years. She subsequently developed uveitis at age 12 and since then she was managed between the uveitis and rheumatology services. The proband's daughter developed episcleritis at the age of 7 years, and arthritis with bilateral intermediate uveitis two years later. NOD2 analyses revealed in both patients the heterozygous c.1494A>C transversion, predicted to lead the novel, missense p.E498D variant in the NOD2 protein. Additional studies including databases searches and in silico bioinformatic predictions strongly support the "likely pathogenic" classification for this novel variant.

CONCLUSIONS

We report a novel pathogenic NOD2 variant in a multiplex family with clinical features compatible with the BS diagnosis. This condition is inherited as a dominant trait in its familial form and should be considered in patients with granulomatous uveitis in association with arthritis and/or dermatitis. Further insight into NOD2 variants and their downstream effects may have implications in the treatment of BS and other inflammatory granulomatous diseases.