Post-infectious Uveitis

Rhegmatogenous Retinal Detachment in Syphilitic Uveitis: A Case Series and Comprehensive Review of the Literature

PURPOSE

Uveitis is the most common ocular manifestation of syphilis. However, an association between syphilitic uveitis and rhegmatogenous retinal detachment (RRD) is not widely recognized. We report a consecutive series of six new cases of syphilitic uveitis complicated by RRD and describe the typical characteristics, clinical course, and surgical management of such cases.

METHODS

Consecutive case series and comprehensive review of the literature.

RESULTS

We identified a total of 19 cases (23 eyes) with syphilitic uveitis subsequently complicated by RRD, including six new cases (seven eyes) reported here and 13 cases (16 eyes) previously reported in the literature. Fifteen patients (79%) were positive for human immunodeficiency virus (HIV) and not on combination antiretroviral therapy. Most retinal detachments developed within two months of uveitis presentation; retinal breaks were often found in areas of previous retinitis. Sixteen eyes (70%) were complicated by early proliferative vitreoretinopathy. Twenty-one eyes underwent surgical repair, of which six (26%) suffered re-detachment. Surgical management commonly involved pars-plana vitrectomy and silicone oil tamponade, with or without scleral buckling. Visual outcomes were generally poor: only six eyes (26%) attained visual acuity of 20/40 or better and 11 eyes (48%) remained 20/200 or worse.

CONCLUSIONS

Patients with syphilitic uveitis, as with viral retinitis, should be monitored closely for the development of retinal tears and RRD. A combination of pars plana vitrectomy with silicone oil tamponade and/or scleral buckle placement is a prudent surgical approach to most cases of syphilitic RRD, although visual prognosis remains guarded.

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.

Relapse in ocular tuberculosis: relapse rate, risk factors and clinical management in a non-endemic country

AIMS

To assess the risk of uveitis relapse in ocular tuberculosis (OTB) following clinical inactivity, to analyse clinical factors associated with relapses and to describe the management strategies for relapses.

METHODS

A retrospective study was conducted on a 10-year patient registry of patients with OTB diagnosed at Erasmus MC in Rotterdam, The Netherlands. Time-to-relapse of uveitis was evaluated with Kaplan-Meier curve and risk factors for relapses were analysed.

RESULTS

93 OTB cases were identified, of which 75 patients achieved clinical inactivity following treatment. The median time to achieve uveitis inactivity was 3.97 months. During a median follow-up of 20.7 months (Q1-Q3: 5.2-81.2) after clinical inactivity, uveitis relapse occurred in 25 of these 75 patients (33.3%). Patients who were considered poor treatment responders for their initial uveitis episode had a significantly higher risk of relapse after achieving clinical inactivity than good responders (adjusted HR=3.84, 95% CI: 1.28 to 11.51). 13 of the 25 relapsed patients experienced multiple uveitis relapse episodes, accounting for 78 eye-relapse episodes during the entire observation period. Over half (46 out of 78, 59.0%) of these episodes were anterior uveitis. A significant number of uveitis relapse episodes (31 episodes, 39.7%) were effectively managed with topical corticosteroids.

CONCLUSIONS

Our results suggest that approximately one-third of patients with OTB will experience relapse after achieving clinical inactivity. The initial disease course and poor response to treatment predict the likelihood of relapse in the long-term follow-up. Topical corticosteroids were particularly effective in relapse presenting as anterior uveitis.

The large Hellenic Study of Uveitis: epidemiology, etiologic factors and classification

PURPOSE

To analyse the demography, etiology, and classification of uveitis at a tertiary academic referral center.

METHODS

An observational study was conducted on the archives of uveitic patients at the Ocular Inflammation Service of the Department of Ophthalmology at the University Hospital of Ioannina (Greece) from 1991 to 2020. This study aimed to investigate the epidemiological profile of patients, including their demographics and the main etiologic factors of uveitis.

RESULTS

Out of 6191 cases with uveitis, 1925 were infectious, 4125 were non-infectious, and an overall of 141 masquerade syndromes were recorded. Among these cases, 5950 patients were adults, with a slight female predominance, while 241 were children (< 18 years old). Interestingly, 24.2% of cases (1500 patients) were associated with 4 specific microorganisms. Herpetic uveitis (HSV-1 and VZV/HZV) was the most common cause of infectious uveitis (14.87%), followed by toxoplasmosis (6.6%) and tuberculosis (2.74%). In 49.2% of non-infectious uveitis cases, no systematic correlation was found. The most frequent causes of non-infectious uveitis included sarcoidosis, white dot syndromes, ankylosing spondylitis, lens-induced uveitis, Adamantiades-Behçet disease, and idiopathic juvenile arthritis. Infectious uveitis was more common in the rural population, whereas non-infectious uveitis was more frequently recorded in the urban population CONCLUSIONS: Although our study was conducted on a predominantly white Caucasian population, it also reflects the effect of increasing immigration, improvements of diagnostic techniques, changes in referral patterns, and various actual changes in disease incidence.

Systemic prime exacerbates the ocular immune response to heat-killed Mycobacterium tuberculosis

Post-infectious uveitis describes the condition of chronic immune mediated ocular inflammation associated with pathogens such as Mycobacterium tuberculosis (Mtb). Mtb associated post-infectious uveitis can be modeled in mice by intravitreal injection of heat-killed Mtb (HKMtb). To better understand how prior systemic exposure to the pathogen alters the local immune response to Mtb, we used flow cytometry and multiplex ELISAs to compare ocular responses to intravitreal HKMtb in the presence or absence of a systemic "prime" of HKMtb. Priming resulted in exacerbation of local inflammation with significantly increased clinical and histologic inflammation scores and increased vitreous cytokines concentrations one day after intravitreal injection of HKMtb. Seven days after injection, uveitis in unprimed animals had largely resolved. In contrast in primed animals, clinical signs of chronic inflammation were associated with a significant increase in the number of ocular T cells, NK cells, and Ly6Chi macrophages and increasing vitreous concentrations of IL-17, VEGF, MIG(CXCL9), IP-10(CXCL10), IL-12p40 and MIP-1α(CCL3). In mice lacking mature T and B cells (RAG2 deficient), the impact of priming on the ocular immune response was ameliorated with significantly lower vitreous cytokine concentrations and spontaneous resolution of uveitis. Altogether these results suggest that the ocular response to Mtb is exacerbated by prior systemic Mtb infection and chronic post-infectious uveitis is mediated by local production of cytokines and chemokines that amplify Th17 and Th1 responses. This mouse model of chronic Mtb associated uveitis will help elucidate mechanisms of disease in patients with post-infectious uveitis.

Reactivation of juvenile idiopathic arthritis associated uveitis with posterior segment manifestations following anti-SARS-CoV-2 vaccination

Background/purpose

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in the pediatric population and anterior uveitis is its commonest extra-articular manifestation. Typically the uveitis presents as chronic anterior uveitis and there is limited literature of the posterior segment manifestations of the disease. Similar to other vaccines, anti-SARS-CoV-2 vaccination that began as an urgent measure to control the spread of the SARS-CoV-2 pandemic has not been without adverse events. We are reporting a 19-year-old Asian Indian female who was diagnosed and treated for JIA associated anterior uveitis that was unilateral and was under anti-inflammatory control but showed worsening of uveitis with posterior segment inflammation in both eyes following anti-SARS-CoV-2 vaccination.

Case report

A 19-year-old Asian Indian female with a history of juvenile idiopathic arthritis on treatment with methotrexate, presented with right eye chronic anterior uveitis with peripheral subclinical retinal vasculitis and macular edema which was brought under control following administration of adalimumab. She was inflammation free for 6 months until she received anti-SARS-CoV-2 vaccination and developed new onset floaters in both eyes that were initially noted after the first dose and increased after the second dose. Clinical examination revealed presence of keratic precipitates and grade 1+ anterior chamber inflammation along with vitiritis in both eyes. Fundus fluorescein angiography revealed angiographically active retinal vasculitis without the presence of macular edema in both eyes. This was managed with a short course of topical difluprednate and continuation of systemic immunosuppressive therapy with adalimumab and methotrexate.

Conclusion

JIA associated uveitis results from an autoimmune process which can be controlled with timely immunosuppressive treatment. It is important to be aware of the potential risk of flare up of uveitis with posterior segment manifestations following anti- SARS-CoV-2 vaccination.

Zika Virus Infection of Human Iris Pigment Epithelial Cells

During recent Zika epidemics, adults infected with Zika virus (ZIKV) have developed organ-specific inflammatory complications. The most serious Zika-associated inflammatory eye disease is uveitis, which is commonly anterior in type, affecting both eyes and responding to corticosteroid eye drops. Mechanisms of Zika-associated anterior uveitis are unknown, but ZIKV has been identified in the aqueous humor of affected individuals. The iris pigment epithelium is a target cell population in viral anterior uveitis, and it acts to maintain immune privilege within the anterior eye. Interactions between ZIKV and human iris pigment epithelial cells were investigated with infectivity assays and RNA-sequencing. Primary cell isolates were prepared from eyes of 20 cadaveric donors, and infected for 24 hours with PRVABC59 strain ZIKV or incubated uninfected as control. Cytoimmunofluorescence, RT-qPCR on total cellular RNA, and focus-forming assays of culture supernatant showed cell isolates were permissive to infection, and supported replication and release of infectious ZIKV. To explore molecular responses of cell isolates to ZIKV infection at the whole transcriptome level, RNA was sequenced on the Illumina NextSeq 500 platform, and results were aligned to the human GRCh38 genome. Multidimensional scaling showed clear separation between transcriptomes of infected and uninfected cell isolates. Differential expression analysis indicated a vigorous molecular response of the cell to ZIKV: 7,935 genes were differentially expressed between ZIKV-infected and uninfected cells (FDR < 0.05), and 99% of 613 genes that changed at least two-fold were up-regulated. Reactome and KEGG pathway and Gene Ontology enrichment analyses indicated strong activation of viral recognition and defense, in addition to biosynthesis processes. A CHAT network included 6275 molecular nodes and 24 contextual hubs in the cell response to ZIKV infection. Receptor-interacting serine/threonine kinase 1 (RIPK1) was the most significantly connected contextual hub. Correlation of gene expression with read counts assigned to the ZIKV genome identified a negative correlation between interferon signaling and viral load across isolates. This work represents the first investigation of mechanisms of Zika-associated anterior uveitis using an in vitro human cell model. The results suggest the iris pigment epithelium mounts a molecular response that limits intraocular pathology in most individuals.

Immune Privilege: The Microbiome and Uveitis

Immune privilege (IP), a term introduced to explain the unpredicted acceptance of allogeneic grafts by the eye and the brain, is considered a unique property of these tissues. However, immune responses are modified by the tissue in which they occur, most of which possess IP to some degree. The eye therefore displays a spectrum of IP because it comprises several tissues. IP as originally conceived can only apply to the retina as it contains few tissue-resident bone-marrow derived myeloid cells and is immunologically shielded by a sophisticated barrier – an inner vascular and an outer epithelial barrier at the retinal pigment epithelium. The vascular barrier comprises the vascular endothelium and the glia limitans. Immune cells do not cross the blood-retinal barrier (BRB) despite two-way transport of interstitial fluid, governed by tissue oncotic pressure. The BRB, and the blood-brain barrier (BBB) mature in the neonatal period under signals from the expanding microbiome and by 18 months are fully established. However, the adult eye is susceptible to intraocular inflammation (uveitis; frequency ~200/100,000 population). Uveitis involving the retinal parenchyma (posterior uveitis, PU) breaches IP, while IP is essentially irrelevant in inflammation involving the ocular chambers, uveal tract and ocular coats (anterior/intermediate uveitis/sclerouveitis, AU). Infections cause ~50% cases of AU and PU but infection may also underlie the pathogenesis of immune-mediated “non-infectious” uveitis. Dysbiosis accompanies the commonest form, HLA-B27–associated AU, while latent infections underlie BRB breakdown in PU. This review considers the pathogenesis of uveitis in the context of IP, infection, environment, and the microbiome.

Identification of unique proteins in vitreous fluid of patients with noninfectious uveitis

PURPOSE

Uveitis is a cause for concern in the developing countries like India. Its poor diagnosis and lack of proper therapeutics often cause blindness in children and young adults. Moreover, the exact mechanism of pathogenesis of different types of uveitis is still elusive. Modern proteomic techniques are found to be advantageous for an in-depth understanding of the ocular physiology using proteomic diversity. Our aim was to identify unique proteins involved in the pathogenesis of autoimmune or noninfectious uveitis.

METHODS

Vitreous fluid samples (n = 90) were obtained from infectious (N = 34) and noninfectious (N = 56) uveitis patients, and their protein profiles were compared by analysing sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and 2D electrophoresis. Unique proteins were identified through matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and further studied for pathway analysis.

RESULTS

Protein spots having different molecular weights were observed in noninfectious vitreous fluid samples. Enzymatic digestion of these spots after MALDI-TOF MS analysis revealed different proteins. We identified 25 different proteins through SDS-PAGE and 22 through 2D electrophoresis. 50% of the proteins from SDS-PAGE were associated with heterotrimeric G-protein signalling pathway-rod outer segment phototransduction. 50% proteins from SDS-PAGE and 20% from 2D electrophoresis revealed association with de novo purine biosynthesis. Carbonic anhydrase 1 and serpin B3 were found to be common in both analyses.

CONCLUSION

High-throughput proteomic and pathway analyses have exposed the potential association of these proteins with autoimmune pathogenesis in uveitis. The exact role of most of the proteins in autoimmune uveitis is yet to be unfurled.

MTBDRplus for the rapid diagnosis of ocular tuberculosis and screening of drug resistance

PurposeTimely diagnosis of intraocular tuberculosis (IOTB) along with detection of drug resistance can save many eyes from visual impairment. With the growing incidence of IOTB and rising drug resistance, a reliable diagnostic platform for simultaneous detection of the agent and mutated gene is urgently needed. The MTBDRplus assay was evaluated directly on vitreous fluid samples for the same.Patients and methodsIn a prospective study, The MTBDRplus assay was performed on 127 vitreous fluid samples (77 'study group' comprising cases of presumed ocular tuberculosis and 50 'control group' cases of disease controls (n=25) and non-uveitic controls (n=25)). All samples positive by MTBDRplus assay were subjected to gene sequencing to confirm the mutations for rifampicin and isoniazid resistance.ResultsThe MTBDRplus assay produced a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 36.36%, 100%, 100%, and 50.50%, respectively, for the detection of IOTB. Among the 28 cases from study group that were positive by MTBDRplus assay, rifampicin resistance was reported in six and isoniazid resistance in two cases. On sequencing of rpoB and katG gene, one case of false rifampicin-resistant by MTBDRplus was found. The other resistant isolates showed concordant mutations between MTBDRplus assay and sequencing.ConclusionThe MTBDRplus assay is an effective tool for the rapid diagnosis of IOTB along with detection of drug resistance, thereby improving the outcome in IOTB.