Developing a pathway for the diagnosis and management of ocular tuberculosis. The pan-LOndon Ocular tuberculosis Pathway-LOOP

Infectious eye disease in the 21st century-an overview

Infectious diseases affecting the eye often cause unilateral or asymmetric visual loss in children and people of working age. This group of conditions includes viral, bacterial, fungal and parasitic diseases, both common and rare presentations which, in aggregate, may account for a significant portion of the global visual burden. Diagnosis is frequently challenging even in specialist centres, and many disease presentations are highly regional. In an age of globalisation, an understanding of the various modes of transmission and the geographic distribution of infections can be instructive to clinicians. The impact of eye infections on global disability is currently not sufficiently captured in global prevalence studies on visual impairment and blindness, which focus on bilateral disease in the over-50s. Moreover, in many cases it is hard to differentiate between infectious and immune-mediated diseases. Since infectious eye diseases can be preventable and frequently affect younger people, we argue that in future prevalence studies they should be considered as a separate category, including estimates of disability-adjusted life years (DALY) as a measure of overall disease burden. Numbers of ocular infections are uniquely affected by outbreaks as well as endemic transmission, and their control frequently relies on collaborative partnerships that go well beyond the remit of ophthalmology, encompassing domains as various as vaccination, antibiotic development, individual healthcare, vector control, mass drug administration, food supplementation, environmental and food hygiene, epidemiological mapping, and many more. Moreover, the anticipated impacts of global warming, conflict, food poverty, urbanisation and environmental degradation are likely to magnify their importance. While remote telemedicine can be a useful aide in the diagnosis of these conditions in resource-poor areas, enhanced global reporting networks and artificial intelligence systems may ultimately be required for disease surveillance and monitoring.

BTS clinical statement for the diagnosis and management of ocular tuberculosis

The BTS clinical statement for the diagnosis and management of ocular tuberculosis (TB) draws on the expertise of both TB and and ophthalmic specialists to outline the current understanding of disease pathogenesis, diagnosis and management in adults. Published literature lacks high-quality evidence to inform clinical practice and there is also a paucity of data from animal models to elucidate mechanisms of disease. However, in order to improve and standardise patient care, this statement provides consensus points with the currently available data and agreed best practice.

Anti-TB monotherapy for choroidal tuberculoma: an observational study

BACKGROUND

Choroidal tuberculoma is possibly the most unequivocal manifestation of ocular infection with Mycobacterium tuberculosis. Here, we investigate the need for adjunctive corticosteroids in the management of this infection. We have compared the efficacy of anti-tubercular therapy (ATT) with or without oral corticosteroids, in management of choroidal tuberculoma.

METHODS

We report a retrospective, observational study of patients treated with ATT for choroidal tuberculoma. Group A patients were treated with standard 6-month ATT alone, and Group B with ATT and oral corticosteroids, with/without intravitreal triamcinolone/ bevacizumab injections. Primary outcome measure was time to complete resolution of lesions. Secondary measures were time to first sign of resolution and change in best corrected visual acuity (BCVA) at final visit.

RESULTS

Fourteen patients were included in the study-seven in Group A and seven in Group B. Both groups had similar duration of symptoms and size of lesions but not baseline BCVA (p = 0.02). Perilesional fluid was noted in all eyes in each group. Mean time to complete resolution in group A was 1.89 ± 0.28 (range 1.25-2) months, significantly lesser than group B (5.17 ± 2.64 [range 2-9] months, p = 0.005, Mann-Whitney test). Mean time to first sign of resolution (range from 5 days to 10 weeks, p = 0.35) and mean change in BCVA between presentation and final follow up (p = 0.2) were comparable between both groups.

CONCLUSION

Anti-TB monotherapy alone, may be sufficient for resolution of at least, select cases of choroidal tuberculoma, without the need for adjunctive corticosteroids.

Tubercular Retinal Vasculitis: Diagnostic Dilemma and Management Strategies

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

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.

Characterization of and advanced diagnostic methods for ocular tuberculosis and tuberculosis

Tuberculosis (TB) is an airborne infection caused by Mycobacterium tuberculosis that usually affects the lungs. Timely treatment of active TB, diagnosis and prevention of latent TB are very important. However, extrapulmonary TB affects almost any tissues around the eye and orbit, and it then requires a high degree of suspicion to accurately diagnose. Diagnostic delays are common and may lead to morbidity. For ophthalmologists and infectious disease specialists, it is important to work together to accurately diagnose and treat ocular tuberculosis (OTB) to prevent vision loss. This review reports the latest advanced diagnostic methods for active TB and latent TB as well as various known manifestations of OTB. Important elements of diagnosis and treatment are also reviewed.