Tuberculosis

Detection of Mycobacterium tuberculosis DNA in intraocular fluid of 11 suspected tuberculous uveitis patients by multiplex PCR

BACKGROUND

This study aims to detect Mycobacterium tuberculosis complex (MTBC) DNA in intraocular fluid from clinically suspected tuberculous uveitis patients using multiplex polymerase chain reaction (PCR) and investigate the diagnostic utility of multiplex PCR for tuberculous uveitis.

METHODS

Primers targeting three specific genes (MPB64, CYP141, and IS6110) within the MTBC genome were designed. Multiplex PCR was conducted using DNA from the H37Rv strain as well as DNA extracted from fluids of confirmed tuberculosis patients to assess primer specificity and method feasibility. Intraocular fluid samples were collected during the initial visit for multiplex PCR detection of MTBC DNA. The results of multiplex PCR tests were correlated with intraocular fluid findings and clinical profiles of patients clinically diagnosed with tuberculous uveitis who underwent standard antituberculosis therapy.

RESULTS

Multiplex PCR was employed to detect MTBC DNA in intraocular fluid samples from 15 patients clinically suspected of having tuberculous uveitis, with no amplification bands observed in the DNA lanes for the three target genes. T-cell spot test (T-SPOT) results were positive in 11 patients (100%), while purified protein derivative (PPD) tests were positive in 5 patients (45.5%). Abnormal chest CT findings were noted in 4 patients (36.4%), including one case of active pulmonary tuberculosis and three cases of inactive pulmonary tuberculosis. Retinal vasculitis was observed in 6 eyes (46.2%), panuveitis in 5 eyes (38.5%), and intermediate uveitis in 2 eyes (15.4%). The average duration of antituberculosis therapy administered to the 11 patients was 7.1 months (range: 6-10 months). The medium LogMAR Best Corrected Visual Acuity (BCVA) significantly improved at the last follow-up (Z=-2.371, P = 0.018).

CONCLUSIONS

Standard antituberculosis therapy demonstrated effectiveness in treating 11 patients clinically suspected of having tuberculous uveitis despite the absence of detectable MTBC DNA in intraocular fluid via multiplex PCR. Further investigation is warranted to elucidate the role of PCR in diagnosing ocular tuberculosis among Chinese individuals.

Recent advances in gold nanoparticles-based biosensors for tuberculosis determination

Tuberculosis (TB) is one of the major killer diseases affecting lung parenchymal tissues. Mycobacterium tuberculosis (Mtb) is the bacterium that causes it. It most commonly affects the lungs, although it can affect any part of the body, including the stomach, glands, bones, and nervous system. Although anti-mycobacterial drugs are available, it remains a major threat to public health due to the rise of drug-resistant strains, and early and accurate diagnosis is very important. Currently, research science and medical communities are focusing on the use of cost-effective biosensors to manage human biological processes and assess accurate health diagnostics. Due to their high sensitivity in chemical and biological assays, nanomaterials have been considered in the field of biosensors for better diagnosis, and among them, gold nanoparticles (AuNPs) can play an important role in accelerating the diagnosis of TB. Superior biocompatibility, conductivity, catalytic properties, high surface-to-volume ratio, and high density enable their widespread use in the fabrication of biosensors. This review evaluates the diagnostic accuracy of AuNP-based biosensors for the detection of Mtb. According to different transducers of biosensors, their structure, performance, advantages and limitations are summarized and compared. Moreover, the upcoming challenges in their analytical performance have been highlighted and the strategies to overcome those challenges have been briefly discussed.

Tuberculosis of the eye, case series study

Tuberculosis of the eye represents a challenge throughout the world, and there is a continuous debate about its pathophysiology, diagnosis, and treatment. The present research represents an interventional prospective study focusing on the variable clinical presentations, and the diagnostic and therapeutic characteristics of ocular tuberculosis. Fifteen eyes from nine cases were diagnosed with ocular tuberculosis, treated, and followed up between 2010 and 2020. The diagnosis was based on (1) a compatible clinical picture, (2) highly positive Tuberculin skin test or a positive IGRA test (Interferon-Gamma Release Assays), (3) a dramatic response to anti-tuberculous drugs without systemic steroid. Mean age was 41.22±13.64 years; eight cases were females 89.8%, one male 11.1%. Only one case had preexisting pulmonary tuberculosis. Bilateral ocular involvement occurred in two thirds of cases (66.7%). The most common clinical presentation was intermediate uveitis (33.3%), followed by multifocal choroiditis (20%). All cases were cured without relapse for the 2–10 years of follow-up, after taking oral anti-tuberculous drugs for 6–12 months. No systemic steroids were given, only topical steroid drops, as indicated. In conclusion, ocular tuberculosis is a mysterious condition with a wide-range of clinical presentations and should be considered in the differential diagnoses of any type of intraocular inflammation, or any unexplained reduction in vision. Oral anti-tuberculous drugs with or without topical steroids are sufficient to improve vision, produce, cure, and prevent relapse.

Presumed Latent Tuberculosis-related Intermediate Uveitis Manifesting as Recurrent Vitreous Hemorrhage

Purpose: We report a case of recurrent vitreous hemorrhage in a patient with presumed latent tuberculosis-related intermediate uveitis, and we review the literature.Case summary: A 58-year-old male visited our clinic complaining of ocular pain, conjunctival hyperemia, decreased vision, and uncontrolled intraocular pressure (IOP) in the left eye. The best-corrected visual acuity (BCVA) was 0.4 and the IOP of the left eye was 34 mmHg. Slit lamp examination revealed conjunctival hyperemia, corneal edema, and inflammatory cells in the anterior chamber and anterior vitreous; fundus examination revealed mild vitreous opacity attributable to vitritis. The high IOP and the intraocular inflammation were treated with antiglaucoma agents and corticosteroids under the impression of chronic anterior uveitis and uveitic glaucoma. Of the tests performed to identify the cause of the uveitis-related vitreous hemorrhage, the interferon-gamma release assay was positive. A presumptive diagnosis of latent tuberculosis-related uveitis was made after pulmonary tuberculosis was excluded by our respiratory internal medicine department. Isoniazid was administered for 9 months. The vitreous hemorrhage recurred 1 month after antituberculosis therapy commenced but, at 2 months, all of the hemorrhage was absorbed and the BCVA improved to 1.0 without further recurrence.Conclusions: Intraocular tuberculosis can present with various clinical manifestations. If tuberculosis-related uveitis is presumed, tests for latent and manifest tuberculosis should be scheduled to allow of early diagnosis and immediate antituberculosis therapy.

Current Approach for the Diagnosis and Management of Noninfective Scleritis

ABSTRACT

Scleritis is a rare, vision-threatening inflammation of the sclera that is often associated with life-threatening systemic illnesses. Rheumatoid arthritis remains the most common associated systemic rheumatic disease and the commonest systemic association of scleritis. Granulomatosis with polyangiitis is the most common cause of vasculitis-associated scleritis. The etiopathogenesis of scleritis remains unclear, but can be immune complex-mediated or due to a local delayed hypersensitivity reaction. Scleritis can involve either the anterior or posterior sclera, and has a wide spectrum of clinical presentations. Among the subtypes of scleritis, necrotizing scleritis has an increased risk of complications and is more commonly associated with anterior uveitis and peripheral ulcerative keratitis. Posterior scleritis is often not diagnosed or missed due to its subtle clinical signs and protean manifestations. Meticulous history taking, detailed ocular examination, and a targeted array of investigations with a multi-disciplinary approach to find any underlying systemic disease are crucial for the management of a case of scleritis. Corticosteroids remain the mainstay of short-term treatment of scleritis; mild to moderate scleral inflammation may respond well to treatment with nonsteroidal antiinflammatory drug or topical corticosteroid. Corticosteroid-sparing immunosuppressive therapies are useful in cases with an inadequate response or failure to provide long-term control of inflammation, and to prevent recurrence of scleritis. Biologic agents are increasingly used in the management of scleritis, not responding to the conventional therapies. This review provides an overview of the various subtypes of scleritis and its systemic associations and evaluates current trends in the diagnosis and management of noninfective scleritis.

Newer trends in tubercular uveitis: a case series with systemic correlation

AIM

To determine the spectrum of uveitis, causes of visual loss in systemic tuberculosis (TB), role of investigations and outcome after anti-TB therapy (ATT).

METHODS

A retrospective study was conducted on 250 patients with systemic TB at a referral center in Chennai, South India from April 2016 to May 2019. Systemic workup comprised of Mantoux, chest X-ray, polymerase chain reaction (PCR) and QuantiFERON (QFT) TB Gold. Aqueous humor analysis by nested PCR or real time PCR (RT-PCR) and ancillary ophthalmic investigations such as fundus fluorescein angiography, optical coherence tomography were performed.

RESULTS

Multifocal choroiditis and vasculitis were the most common manifestations (39% and 24% respectively) together accounting for 61% of cases and they had a higher risk of recurrence (3%). Pulmonary tuberculosis (PTB) was more frequently associated with uveitis (18%). Among those with extra-pulmonary tuberculosis (EPTB), uveitis occured in miliary TB (2%), bone (1%) and abdominal TB (1%). Complications such as cystoid macular edema, choroidal neovascular membranes and macular scarring caused visual loss. Aqueous humor analysis detected mycobacterium TB antigen. Collectively, systemic investigations such as chest X-ray, Mantoux test and those performed on blood samples such as PCR and QFT were positive in 39% of patients. In inconclusive patients, nested PCR and/or RT-PCR were done on aqueous humor samples and were diagnostic in 96%. A combination of tests was diagnostic in 92%. ATT in isolation in 71% and combined with corticosteroids in 29% was used for treatment of which signs of resolution and improvement in vision started as early as 6wk in those who were started immediately on corticosteroids and ATT and longer than 3mo in those on ATT alone. Prompt treatment with ATT and corticosteroids improved vision in 23% of our patients within 2mo. Vitritis with choroiditis causes cystoid macular oedema and requires longer duration of ATT. Vision improved in 69%. Complete resolution occurred in 75% and worsening in 12%.

CONCLUSION

A combination of investigations guided by clinical suspicion helps in precise diagnosis. In diagnostic dilemmas analysis of ocular samples is reliable and confirmatory. Screening all patients and a multidisciplinary approach in TB (active, healed or during treatment) is recommended.

Is targeting dysregulation in apoptosis splice variants in Mycobacterium tuberculosis (MTB) host interactions and splicing factors resulting in immune evasion by MTB strategies a possibility?

Mycobacterium tuberculosis (Mtb), is one of the foremost organisms causing mortality in humans, and has been for most of human history. When faced with an infection the human immune system is ordinarily very competent in killing both extracellular and intracellular bacilli. However, Mtb is able to evade the host immune system and is even able to establish a persistent infectious reservoir by "hiding" in the immune cells of the host. While the mechanisms by which the bacteria accomplishes this are not fully understood, it is known that the bacterium can subvert cellular processes in cells such as macrophages that prevent the lysis of the bacteria or the cell undergoing apoptosis. They are also able to interfere with immune cell signalling. One of the greatest effects that Mtb has is too alter the transcriptome of the macrophage. An easy way for the bacterium to accomplish this is to alter the alternative splicing patterns of the host. This can lead to a large change in the population of different protein isoforms, some of which have very different functions when compared to the original protein. At the same time the long history of Mtb infecting humans have led to specific immune reactions that occur in the host immune system in order to fight the infection. Many of these specific reactions involve new isoforms of host defence proteins. In this way the human host can use alternate splicing to create new isoforms of immune- related proteins that are more effective in defending against Mtb.

Study of ocular manifestations in tuberculosis and its association with HIV AIDS in a tertiary care hospital

OBJECTIVE

To assess and understand the prevalence and clinical presentation of ocular morbidity in patients suffering from tuberculosis and compare it with ocular involvement in patients coinfected with tuberculosis and HIV AIDS.

MATERIALS AND METHODS

This was a non-comparative, observational, cross sectional study done on 580 patients, who were diagnosed cases of tuberculosis, pulmonary or extrapulmonary, on or off treatment, visiting the Ophthalmology OPD, Tuberculosis OPD and ART Centre of the institute in the period from March 2015 to March 2018, screened for ocular morbidity.

RESULTS

Out of 580, 408 patients had only tuberculosis and 172 had tuberculosis with HIV AIDS. 108 patients were found to have ocular involvement (18.6%) out of which 63 were males and 45 were females. The prevalence of ocular morbidity in patients with only tuberculosis was found to be 16.4% and in those having both tuberculosis and HIV AIDS was found to be 23.8%.

CONCLUSION

Our study concludes that posterior uveitis, pan uveitis, periphlebitis and vitritis are the most common ocular manifestations in tuberculosis. In patients with both tuberculosis and HIV most common ocular findings included vitritis and herpes zoster ophthalmicus. Our study also concludes that lower CD4 counts (less than 200) in HIV AIDS patient is significantly associated with ocular involvement.

Paradoxical reactions in ocular tuberculosis

Paradoxical reactions following initiation of anti-tubercular therapy have been documented most often in extrapulmonary tuberculosis. A combination of factors such as delayed hypersensitivity, decreased suppressor mechanisms, and an increased response to mycobacterial antigens mediated by the host’s immune system have been implicated in the development of these reactions. Similar worsening in patients with ocular tuberculosis while on treatment has been described. It is therefore important for the clinician to be aware of this occurrence, as prompt recognition and timely institution of corticosteroids and immunosuppressants can lead to restoration of vision. In these patients, an alteration or discontinuation of anti-tubercular therapy may not be indicated.

Orbital Tuberculosis with Intracranial Extension

We report a case of orbital tuberculosis (OTB) with intracranial extension without active tuberculosis in the rest of the body organs or a history of tuberculosis infection. A 29-year-male patient presented with left-sided painful periorbital swelling with pus discharging sinus and visual impairment. Orbital computed tomography revealed contrast enhancing cystic mass lesion in the left orbit with erosion of the lateral and superior orbital wall with intracranial extension. After the failure of 3 weeks' course of oral antibiotics, the patient underwent left lateral orbitotomy, pus was drained out, and granulation tissues were excised. Histopathological examination confirmed OTB. The patient had received antituberculous treatment. Periorbital swelling completely disappeared and vision improved over a period of 2 weeks. OTB should be considered in differential diagnosis of periorbital swelling especially when it does not respond to oral antibiotics.

Tuberculous Uveitis Presenting with a Bullous Exudative Retinal Detachment: A Case Report and Systematic Literature Review

Purpose: To describe tuberculous uveitis (TU) presenting as a bullous retinal detachment (RD) and to perform a comprehensive literature review on TU with similar features. Methods: Observational case report and systematic literature review. Results: An 84-year-old woman presented with bilateral granulomatous uveitis and bullous RD in the left eye. The interferon gamma release assay was strongly positive, but all other tests were unremarkable. The patient was diagnosed with TU and started on anti-tubercular therapy (ATT) and systemic steroids with excellent treatment response. Twenty-six articles (32 cases) reported TU with exudative RD. Choroidal tuberculoma was the most common clinical manifestation, followed by optic disc edema and retinal exudate. Systemic steroids with ATT improved vision in more patients (78.6%) than ATT alone (50.0%) or oral steroids followed by ATT (50.0%). Conclusion: Atypical presentations of TU make diagnosis and treatment difficult. A high level of suspicion for TU is needed to minimize ocular morbidity.

A novel clinical sign in intraocular tuberculosis: Active chorioretinitis within chorioretinal atrophy

Purpose

To report a novel clinical sign in patients with intraocular tuberculosis. The current study is an observational consecutive case series of patients diagnosed with intraocular tuberculosis managed at a tertiary eye care centre from June 1, 2012 to December 31, 2015.

Observations

The diagnosis of intraocular tuberculosis was made in 6 patients based on ocular features suggestive of tuberculosis along with a positive tuberculin skin testing and chest X-ray consistent with tuberculosis. All patients presented with decreased visual acuity ranging from 20/25 to 20/400, anterior chamber reaction, vitritis, multifocal choroiditis and vasculitis. All patients had an area of active chorioretinitis within the zone of pre-existing chorioretinal atrophy, apart from various other signs suggestive of intraocular inflammation. All patients were started on anti-tubercular therapy for a period of 9 months alone or in combination with oral corticosteroids tapered over 3–4 months. A prompt response to the treatment with resolution of chorioretinitis within the chorioretinal atrophy occurred in all patients. In addition, there was resolution of vitritis and improvement in the visual acuity ranging from 20/20 to 20/40 at last follow-up.

Conclusions and importance

and Importance: Active chorioretinitis within an area of chorioretinal atrophy is a novel clinical sign that may indicate intraocular tuberculosis.

Intraocular manifestations of mycobacterium tuberculosis: A review of the literature

Mycobacterium tuberculosis: is most commonly associated with pulmonary infection. However, tuberculosis (TB) can also affect the eye. TB can affect nearly any tissue in the eye, and a high index of suspicion is required for accurate diagnosis, as many of the intraocular manifestations of TB can mimic other, more common diseases. Correct diagnosis is critical because systemic anti-tuberculosis treatment may be required, and vision loss or even loss of the affected eye can occur without proper treatment. Thus, it is important for ophthalmologists and infectious disease specialists to work together to accurately diagnose and treat intraocular TB. This article reports the various known presentations of intraocular TB and reviews important elements of diagnosis and treatment.

Ocular Autoimmune Systemic Inflammatory Infectious Study (OASIS)-report 4: analysis and outcome of scleritis in an East Asian population

Background

The purpose of this study is to evaluate the spectrum of scleritis from database of Ocular Autoimmune Systemic Inflammatory Infectious Study (OASIS) at a tertiary eye referral eye institute in Singapore. Clinical records of 120 patients with scleritis from a database of 2200 patients from Ocular Autoimmune Systemic Inflammatory Infectious Study (OASIS) were reviewed.

Results

56.6% were females, with a mean age of 48.6 ± 15.9 years. 75 (62.5%) had diffuse anterior scleritis, 25 (20.8%) had nodular anterior scleritis, 7 (5.8%) had necrotizing anterior scleritis and 13 (10.8%) had posterior scleritis. Ocular complications were observed in 53.3% of patients, including anterior uveitis (42.5%), raised intraocular pressure (12.5%), and corneal involvement (11.7%). Autoimmune causes were associated with 31 (25.8%) of patients, and 10 (8.3%) patients had an associated infective etiology, much higher than Caucasian studies. 53.3% of patients were treated with oral corticosteroids while 26.7% required immunosuppressives.

Conclusions

Infective etiology needs to be considered in patients of scleritis from Asian origin. In our study and in OASIS database, scleritis was associated with systemic autoimmune disease and ocular complications.

Clinical Features and Prognostic Factors in Presumed Ocular Tuberculosis

PURPOSE

To characterize the clinical features in patients with presumed ocular tuberculosis (TB) and determine prognostic factors of visual outcomes and complications in this disease.

MATERIAL AND METHODS

Retrospective case series of 35 patients (29 females, 6 males) with presumed ocular TB from referral centers in Chile and Spain between 2002 and 2012. Medical records were reviewed, and data regarding clinical features, complications, best-corrected visual acuity (BCVA), duration of disease, extraocular manifestations, and therapy were retrieved. Prognostic factors for low vision (BCVA 20/50 or less), legal blindness (BCVA 20/200 or less), and complications (cataract, glaucoma, and macular lesion) were evaluated. To calculate correlations, we used Spearman's rank correlation test. To determine clinical predictors, we used the binary logistic regression test.

RESULTS

Anterior and non-granulomatous uveitis was the most common types of inflammation. Only 2 (5.7%) patients had respiratory symptoms, and 6 (17.1%) patients had an abnormal chest X-ray at diagnosis. All patients received combined antitubercular therapy with a mean duration of 6.9 ± 2.3 months. A longer duration of symptoms at diagnosis was associated with both low vision and legal blindness. Older patients had a higher risk of legal blindness. A longer duration of symptoms as well as anterior inflammation demonstrated an increased risk for cataract formation. The duration of the symptoms and baseline BCVA had a positive correlation with the final BCVA. Prognostic factors of macular lesions were not found.

CONCLUSIONS

The diagnosis of ocular TB can be difficult due to the lack of extraocular manifestations and the broad spectrum of ocular features. A longer duration of symptoms at diagnosis was associated with poorer visual outcomes and cataracts. Therefore, efforts should be made to avoid a delay in the diagnosis of ocular TB and to identify prognostic factors for visual outcomes and complications.

A case of subretinal tubercular abscess presenting as disc edema

We report a case of ocular tuberculosis (TB) which initially presented with disc edema and was mistaken for optic neuritis. With no definite pathology being identified, the patient was treated on the lines of optic neuritis with intravenous (IV) steroid with beneficial effect. Ocular TB was suspected when he presented later with a subretinal abscess. Based on positive Mantoux, QuantiFERON TB gold results and radiographic findings, a diagnosis of subretinal abscess of presumed tubercular etiology was made. The patient was successfully treated with anti-tubercular therapy. To the best of our knowledge, this is the first case report of ocular TB presenting as disc edema followed by subretinal abscess.

Orbital and external ocular manifestations of Mycobacterium tuberculosis: A review of the literature

Tuberculosis (TB) is an airborne infectious disease caused by Mycobacterium tuberculosis that most commonly affects the lungs. However, extrapulmonary manifestations of TB can affect the eye and surrounding orbital tissues. TB can affect nearly any tissue in the eye, and a high index of suspicion is required for accurate diagnosis. Systemic anti-tuberculosis treatment is required in cases of ocular TB, and steroids are sometimes necessary to prevent tissue damage secondary to inflammation. Delays in diagnosis are common and can result in morbidities such as loss of an affected eye. It is important for ophthalmologists and infectious disease specialists to work together to accurately diagnose and treat ocular TB in order to prevent vision loss. This article reports the various known presentations of orbital and external ocular TB and reviews important elements of diagnosis and treatment.

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.

Evaluation of the Accuracy of T-SPOT.TB for the Diagnosis of Ocular Tuberculosis in a BCG-vaccinated, Non-endemic Population

PURPOSE

To determine the performance of T-SPOT.TB, an interferon gamma release assay test, in patients with ocular tuberculosis (TB) in a BCG-vaccinated, non-endemic population.

METHODS

We employed a nested case-control design. In total, 45 subjects were enrolled (23 patients with ocular tuberculosis and 22 patients with other causes of uveitis). A blood sample was collected from each subject, and T-SPOT.TB was executed. Laboratory professionals were blinded to the disease status of each subject.

RESULTS

Five patients were excluded because of indeterminate results. The calculated sensitivity and specificity were 0.80 and 0.85, respectively. The positive likelihood ratio was 5.33 and the negative likelihood ratio was 0.23. The overall accuracy of the test was 0.83.

CONCLUSIONS

T-SPOT.TB adequately diagnosed ocular TB. This technique is particularly useful in populations where BCG vaccinations are still mandatory.

Clinical manifestations and outcome of tuberculous sclerokeratitis

AIM

To study the clinical manifestations and outcome of patients with tuberculous sclerokeratitis treated with antituberculous therapy without concomitant use of systemic steroids.

METHODS

We reviewed retrospectively the medical records of eight consecutive patients with tuberculous sclerokeratitis. Patients were treated unsuccessfully with topical and/or systemic steroids. They underwent complete ophthalmic examination, systemic evaluation, laboratory investigations and imaging. Tuberculin skin test was done with purified protein derivative (PPD) on all patients. The diagnosis of tuberculous sclerokeratitis was made based on clinical findings of scleritis with adjacent peripheral corneal stromal keratitis, positive PPD test of 15 mm of induration or more, response to antituberculous treatment (ATT) within 4 weeks and exclusion of other causes of sclerokeratitis. Antituberculous drugs were given for a minimum of 6 months without concomitant use of corticosteroids. The outcome measure was resolution of the ocular surface inflammation of the sclera and cornea.

RESULTS

Eight consecutive patients with a diagnosis of tuberculous sclerokeratitis were included. There were one male and seven female patients. The mean age was 29 years with an age range of 7-43 years. The involvement of the sclera was nodular in six patients and diffuse in two. The involvement of the cornea consisted of peripheral corneal stromal inflammation adjacent to the area of scleritis. Patients responded to antituberculous medications with complete resolution of the sclerokeratitis without topical or systemic anti-inflammatory agents.

CONCLUSIONS

Antituberculous medications can lead to complete resolution of the sclerokeratitis without concomitant use of steroids, or other anti-inflammatory agents.

Case report: atypical presentation of Mycobacterium tuberculosis uveitis preceding nodular scleritis

Background

Intraocular tuberculosis is uncommon and has various clinical presentations. Lack of specific clinical clues can make the diagnosis challenging. The purpose of this study is to report a clinical presentation of tuberculous iridocyclitis that mimics phacolytic glaucoma and has a distinctive inflammatory deposit in the inner side of the cornea. This report is the first to describe the progression of tuberculous iridocyclitis to nodular scleritis without evidence for extraocular tuberculous infection.

Case presentation

A 78-year-old, immunocompetent woman presented with subacute intraocular inflammation with high intraocular pressure, mimicking phacolytic glaucoma. Distinct pigment keratic precipitates were noted on the first visit. Even though the cataract extraction was uneventful and adequate anti-inflammatory drugs were given, the inflammation did not subside as expected. Seven weeks later, she developed two scleral abscesses, which were subsequently explored for microbiological investigation. The smears of the pus revealed positive acid-fast bacilli stain and PCR for Mycobacterium tuberculosis complex. Eventually, the pus culture grew Mycobacterium tuberculosis. Anti-tuberculosis medications were prescribed. After 1 month of treatment, the abscesses were cured. However, her visual acuity did not improve at the last visit.

Conclusions

This case revealed an unusual presentation and untreated course of tuberculosis iridocyclitis. Pattern of keratic precipitates may indicate the presence of tuberculosis.

Ocular Tuberculosis with Progressive Unilateral Corneal Melting

Objectives

In this case report, we present a patient with ocular tuberculosis presenting with progressive unilateral corneal melting.

Patient

A 47-year-old female was admitted with melting at the inferior half of the peripheral cornea and inferior subconjunctival nodules. Biopsy material of the nodules was negative for tuberculosis bacillus. However, polymerase chain reaction of the biopsy sample revealed the DNA of the bacillus, and the diagnosis was confirmed.

Conclusion

In endemic areas, ocular tuberculosis should be kept in mind in the differential diagnosis of patients with chronic and atypical corneal involvement.

Pathogenesis and Pathology of Intraocular Tuberculosis

Intraocular tuberculosis (TB) is an extremely paucibacillary form of extrapulmonary TB. It likely results from bacterial dissemination to the eye from lungs, localization in ocular tissues, followed later by reactivation and appearance of clinical signs. These have been partly demonstrated in the guinea pig model of ocular TB. Alternative hypotheses have been suggested but are not supported by adequate evidence. Mycobacterial recognition by macrophages and dendritic cells probably leads to activation of several immune pathways, primarily the Th1 and Th17 pathways, as in other TB infections. Histopathology of bacteriologically proven ocular TB tissues reveals granulomatous inflammation with central caseous necrosis containing occasional acid-fast organisms. Recent reports have also demonstrated intraretinal granuloma in the vicinity of retinal vessels and T-cell infiltration of epiretinal membranes, in cases of TB retinal vasculitis.

Treatment of severe non-infectious uveitis in high-risk conditions (Part 2): systemic infections; management and safety issues

INTRODUCTION

Management of patients with severe immune-mediated uveitis requires the use of immunosuppressive (IS) drugs in selected cases. This may be particularly challenging in certain patients with associated conditions, which may increase the risk of side effects or modify guidelines for the use of such drugs. Chronic viral and mycobacterial infections in the setting of non-infectious uveitis create a number of diagnostic but also therapeutic dilemmas to clinicians because they can be exacerbated by IS therapies with detrimental effects.

AREAS COVERED

In this review, we will focus on very specific chronic infections that can be affected by IS therapies: human immunodeficiency virus infection, chronic hepatitis virus infection and tuberculosis. The main aim of this review is to provide an updated and comprehensive practical guide for practitioners regarding the therapeutic decision-making and management of patients with non-infectious uveitis affected by the aforementioned infectious conditions.

EXPERT OPINION

Clinicians should be aware of the risk of viral and mycobacterial reactivation of an underlying infection during IS therapy. However, most of these conditions do not represent an absolute contraindication if one were able to apply an appropriate prior screening and close monitoring of such therapy.

Ophthalmic manifestations of systemic diseases--part 2: metabolic, infections, granulomatoses, demyelination, and skeletal dysplasias

The orbit and globe can be secondarily involved in various systemic diseases. These range from tumor and tumorlike conditions, metabolic, infective, inflammatory, granulomatous demyelinating diseases, and skeletal dysplasias. In this article, we discuss the imaging appearances of the remaining systemic pathologies affecting the orbit such as (1) endocrine or metabolic, (2) infectious, (3) inflammatory or granulomatous, (4) demyelinating diseases, and (5) skeletal dysplasias. As the imaging appearances of various systemic diseases tend to overlap, we also introduce a list of pattern-based systemic differential diagnoses for commonly encountered orbital imaging findings. Awareness of the imaging appearances of the various ophthalmic manifestations of systemic diseases can help a radiologist to suggest the most appropriate differential diagnosis to guide further workup and facilitate correct treatment.

The usefulness of interferon-gamma release assay for diagnosis of tuberculosis-related uveitis in Korea

Purpose

To evaluate the usefulness of the interferon-gamma release assay (IGRA) for diagnosing tuberculosis (TB)-related uveitis (TRU).

Methods

Records from 181 patients with ocular signs and symptoms suggestive of TRU and intraocular inflammation of unknown etiology were reviewed. All subjects underwent clinical and laboratory testing, including IGRA, to rule out presence of underlying disease. A diagnosis of presumed TRU was made based on an internist's TB diagnosis and a patient's response to anti-TB therapy. Sensitivity, specificity, and positive predictive values of IGRA for TRU diagnosis were calculated. Clinical characteristics were compared between patients with positive and negative IGRA results.

Results

The sensitivity and specificity of IGRA for TRU were 100% and 72.0%, respectively. Mean age, percentage of patients with retinal vasculitis, and the anatomic type of uveitis were significantly different between patients with positive and negative IGRA results (all p ≤ 0.001). Positive IGRA rates and false-positive rates were significantly different between age and anatomic type groups (both p = 0.001). The positive predictive value of the IGRA among patients with intraocular inflammation was high (70%) when all of younger age (≤40 years), posterior uveitis, and retinal vasculitis were present.

Conclusions

The IGRA is useful for diagnosing TRU in the Korean population, especially when it is used as a screening test. Clinical characteristics, including younger age (≤40 years), posterior uveitis, and retinal vasculitis in IGRA-positive patients, increase the likelihood of the patient having TRU.

Antimicrobial Agents in Ophthalmology

Many types of antimicrobial agents have been introduced for the treatment of ocular infectious diseases. Some ocular infections have been eradicated such as smallpox, while others have been controlled by public health measures such as trachoma. The resilience of viruses and the tenacity of bacteria have led to the evolution of old diseases and the emergence of new infections. Continuous search for new antimicrobial agents for the treatment of infectious diseases is, therefore, highly desirable.

New infectious agents are discovering the human race, and the ecological changes are exposing mankind to new viruses and bacteria. In addition, air travel and disruption of geographic barriers are leading to new forms of infectious diseases.

In the twentieth century, there was a widespread false optimism that infectious diseases are eradicated by antimicrobial agents. It was soon discovered that many infections require new strategies for the treatment of ocular infections.

The new antimicrobial agents that have been introduced over the past century can be classified into four major categories including (1) antibiotics that inhibit cell wall synthesis and integrity, (2) antibiotics that inhibit and suppress cell membrane functions, (3) antibiotics that interfere the protein synthesis, and (4) antibiotics that modulate nucleic acid synthesis.

The selection of antimicrobial agents for the treatment of ocular infectious diseases is based on the most frequently encountered organisms, the pharmacokinetics of the antibiotics, the dosage required, the ocular penetration, and the cost of therapy. The stumbling blocks to safe and effective antimicrobial therapy in ocular infections include the resistance of the microorganisms, toxicity of the drug, and poor ocular penetration of antimicrobial agents.

[Treatment of presumed tuberculous uveitis affecting the posterior segment: diagnostic confirmation and long term outcomes]

OBJECTIVE

To determine the level of agreement with the presumed diagnosis and long term clinical outcomes after antituberculous therapy (ATT) in a group of patients with presumed tuberculous uveitis (PTU) affecting the posterior segment.

METHODS

Retrospective case series.

RESULTS

A total of 17 patients with chronic refractory or newly diagnosed uveitis affecting the posterior segment were included. All included patients were diagnosed with PTU and received ATT. Median follow-up after ATT was 34 months (range 2-60). Complete control of inflammation was observed in 14/17 patients (82.3%) during the treatment period, and only 4/17 patients (23.5%) had a uveitis relapse over the entire follow-up period after ATT. All patients who had uveitis relapses (4/4), but none from the remaining group (0/13), required immunosuppressive therapy of some kind after ATT. The response to ATT was able to confirm diagnosis of PTU in 14/17 (82.3%) included patients.

CONCLUSION

When a clinical suspicion of PTU affecting the posterior segment exists, ATT may be highly effective for both confirming the diagnosis and resolving the inflammatory process. Thus, ATT may offer additional advantages, such as preventing latent-tuberculosis reactivations due to immunosuppressive therapy, and decreasing the number and/or severity of uveitis relapses in some patients. Prospective, randomized studies including a larger number of patients are required to support these and other potential advantages of ATT in such patients.

Update on ocular tuberculosis

PURPOSE OF REVIEW

Despite recent downtrends, tuberculosis remains a worldwide public health concern. This review provides an update on recent demographic data, clinical and experimental data, and diagnostic modalities.

RECENT FINDINGS

Quantitative PCR showing mycobacterial load in intraocular fluids may have an emerging role in the diagnosis of ocular tuberculosis when used in combination with ophthalmic features of tuberculosis. Recent investigations in porcine models of ocular tuberculosis have provided valuable insight into the microbiologic, histologic, and clinical features of Mycobacterium tuberculosis infection of the choroid. Differentiating features between sarcoidosis and tuberculosis include tuberculin skin test status, the presence of ocular surface disease, and the anatomic relationship between vasculitis and choroiditis.

SUMMARY

The diagnosis of presumed ocular tuberculosis remains a clinical challenge with currently available diagnostic modalities. Although newer interferon-γ release assays can distinguish exposure to M. tuberculosis from the Bacille-Calmette-Guérin vaccine strain, they currently lack the specificity to distinguish between latent tuberculosis infection and active tuberculosis. Continued improvement in the currently available molecular diagnostic techniques including quantitative PCR may be valuable in our ability to establish an earlier etiologic diagnosis and institute appropriate antimycobacterial therapy.

Serpiginous choroiditis and infectious multifocal serpiginoid choroiditis

Serpiginous choroiditis (SC) is a posterior uveitis displaying a geographic pattern of choroiditis, extending from the juxtapapillary choroid and intermittently spreading centrifugally. The choroiditis involves the overlying retinal pigment epithelium, and the outer retina. This intraocular inflammation typically involves both eyes in otherwise healthy, middle-aged individuals with no familial or ethnic predilection. Pathogenesis is unclear; based on limited histopathologic studies, however, favorable response to immunosuppressive agents, and the absence of association with systemic or local infectious or noninfectious diseases, an organ-specific autoimmune inflammation seems likely to be the underlying process. Patients, particularly from tuberculosis-endemic regions, may present with fundus changes simulating SC, but show evidence of active tuberculosis and/or the presence of mycobacterial DNA in the aqueous humor. This has been referred to as serpiginous-like choroiditis, but we prefer the description multifocal serpiginoid choroiditis (MSC). We present the distinguishing features of SC and infectious multifocal serpiginoid choroiditis simulating SC. The distinction is crucial to avoid unnecessarily treating SC with antimicrobial agents. Advances in diagnostic and imaging modalities can help differentiate SC from MSC. Novel local and systemic treatment approaches improve the outcome and preserve vision in SC.

Indirect supportive evidence for diagnosis of tuberculosis-related uveitis: from the tuberculin skin test to the new interferon gamma release assays

PURPOSE

To evaluate clinical and paraclinical parameters for the indirect diagnosis of tuberculosis-related uveitis (TRU).

METHODS

Prospective 2-year study in a tertiary referral centre. Patients with clinically suspected TRU were recruited. Demographical and clinical data were recorded. QuantiFERON(®) -TB Gold (QFT), tuberculosis skin test (TST) and pulmonary X-ray were performed, and other possible uveitis aetiologies were ruled out. Further investigations were also performed case by case after consultation. After final assessment, standard antituberculosis therapy was started if TRU was considered highly probable. Finally, diagnosis of TRU was established according to current criteria and set as gold standard. Strength of association for TRU was determined by odds ratio and compared by appropriate tests. Concordance and binary classification tests were also assessed.

RESULTS

  The study included 103 patients, 54 men and 49 women. Mean age 45.6 years. Sixty-eight patients were Spanish-born and 35 were foreign-born. Final diagnosis included 33 (32%) cases of TRU and 70 (67%) cases with other diagnoses. Asian origin (OR = 3.50, p = 0.046), previous tuberculosis (TB) contact (OR = 2.61, p = 0.026), TB in the past (OR = 6.18, p = 0.004) and associated retinal vasculitis (OR = 7.85, p < 0.001) were significantly related to TRU. Sensitivity (S) and specificity (Sp) of the TST and QFT did not differ significantly (S 87% versus 90% and Sp 85% versus 82%, respectively) with fair agreement (k = 0.607).

CONCLUSION

In a Western urban multi-ethnic population, patients from Asia, TB history or contact in the past and vasculitis are at higher risk of TRU. TST and QF are complementary providing enough S and Sp to support the diagnosis.

[Papilledema secondary to tuberculous meningitis in a patient with type 1 diabetes mellitus]

CASE REPORT

The case is presented of a 29-year-old woman who complained of headache over a period of several days, with loss of visual acuity and pain in her left eye. She had a 3-year history of type 1 diabetes mellitus, and was an immigrant from Ecuador. The funduscopic examination revealed a papilledema. The polymerase chain reaction (PCR) study of the cerebrospinal fluid was positive for Mycobacterium tuberculosis (MTB). She showed a marked improvement after treatment with anti-TB drugs.

DISCUSSION

About a third of the world's population has a latent infection of MTB, comorbidity between diabetes mellitus and tuberculosis has been reported, particularly in undeveloped countries.

Clinical signs of uveitis associated with latent tuberculosis

BACKGROUND

  To identify the clinical ocular signs of uveitis associated with latent tuberculosis.

DESIGN

  Retrospective case-control study.

PARTICIPANTS

  Consecutive patients from Singapore National Eye Centre Uveitis over 9 years. Sixty-two patients with uveitis associated with latent tuberculosis were compared with 72 matched controls diagnosed with other known uveitides.

METHODS

  Patients were categorized as: (A) predominantly anterior segment inflammation (anterior uveitides) and (B) predominantly posterior segment inflammation (intermediate, posterior or pan-uveitides). The diagnostic performance of combining these clinical signs with investigations such as interferon-gamma release assay positivity and chest X-ray results suggestive of pulmonary tuberculosis was done using area under the receiver operator characteristic curve.

MAIN OUTCOME MEASURES

  Sensitivity, specificity and likelihood of association with tuberculosis of various clinical signs.

RESULTS

  Extensive posterior synechiae and concomitant anterior scleritis in Group A; low-grade anterior chamber activity, retinal phlebitis and severe vitritis in Group B were significantly associated with latent tuberculosis. Combining these clinical signs with a positive interferon-gamma release assay and tuberculin skin test improved the diagnostic performance in both groups (area under the receiver operator characteristic curve for Group A = 0.779; Group B = 0.789).

CONCLUSION

  Patients with a combination of suggestive clinical signs with positive interferon-gamma release assay and tuberculin skin test are more likely to be accurately diagnosed with uveitis associated with latent tuberculosis, which responds to anti-tuberculosis therapy.

Interferon-gamma release assay as a diagnostic test for tuberculosis-associated uveitis

BACKGROUND

To study the use of interferon-gamma release assay (IFN-γ) (IGRAs) as a diagnostic test for tuberculosis (TB)-associated uveitis (TAU).

DESIGN

Prospective cohort study.

PARTICIPANTS

Consecutive new patients (n=162) with clinical ocular signs suggestive of TAU, seen >1 year period at a single tertiary center.

METHODS

All subjects underwent investigations to rule out underlying disease, including T-SPOT.TB and tuberculin skin test (TST). Twenty-one subjects with underlying disease and three with interdeterminate T-SPOT.TB results were excluded. Those with T-SPOT.TB- or TST-positive results were referred to infectious diseases physician for evaluation. Anti-TB therapy (ATT) was prescribed if required. Patients' treatment response and recurrence were monitored for six months after completion of ATT, if given; or 1 year if no ATT was given.

MAIN OUTCOME MEASURE

Diagnosis of TAU.

RESULTS

Mean age of study cohort (n=138) was 46.8 ± 15.3 years. Majority were Chinese (n=80, 58.0%) and female (n=75, 54.3%). TST was more sensitive than T-SPOT.TB (72.0% vs 36.0%); but T-SPOT.TB was more specific (75.0% vs 51.1%) for diagnosing TAU. Patients with either a T-SPOT.TB (1.44; 95% confidence intervals (CI), 0.86-2.42) or TST (1.47; 95% CI, 1.12-1.94)-positive result are more likely to have TAU. The accuracy of diagnosing TAU increases when both tests are used in combination (area under the receiver operator curve=0.665; 95% CI, 0.533-0.795). Patients with both tests positive are 2.16 (95% CI, 1.23-3.80) times more likely to have TAU. Negative T-SPOT.TB or TST results do not exclude TAU (negative likelihood ratios <1.0).

CONCLUSIONS

We recommend using a combination of clinical signs, IGRA, and TST to diagnose TAU.

Tubercular serpiginous-like choroiditis

Choroidal tuberculosis (TB) infection may present itself as a diffuse choroiditis that resembles serpiginous choroiditis, usually treated with immunossupressants. Recent studies have demonstrated that patients with serpiginous-like choroiditis and evidence of systemic or latent TB are best treated with antituberculosis treatment (ATT) in addition to the corticosteroid therapy. The authors present a case of a 58-year-old man with decreased vision in his left eye. His best-corrected visual acuity was 20/20 right eye and 20/200 left eye. Funduscopic examination revealed a diffuse choroiditis. Mantoux skin test showed an area of induration measuring 30×35 mm and the patient started ATT with complete resolution of retinal lesions after 2 weeks of treatment. His final visual acuity was 20/25 in the left eye with no recurrences over a follow-up of 6 months. The use of ATT in these patients is likely to reduce active inflammation and eliminate future recurrences.

Presumed tubercular retinal vasculitis with serpiginous-like choroiditis in the other eye

A 17-year old boy, with decreased vision in right eye for 15 days, presented with retinal periphlebitis in multiple quadrants of the right eye and partially active serpiginous-like choroiditis in the left eye. Tuberculin test was positive (16 mm induration), and chest X-ray showed hilar lymphadenopathy. The patient was treated with a 9-month course of anti-tubercular therapy and a tapering dose of oral corticosteroids. Both retinal vasculitis and choroiditis lesions resolved over 3-4 months. Retinal neovascularization in the right eye was treated with laser photocoagulation. There was no recurrence over an 18-month follow-up. The probable pathogenic mechanism for such a presentation is discussed.