The microbiome in HLA-B27-associated disease: implications for acute anterior uveitis and recommendations for future studies.

The pathogenesis of human leukocyte antigen (HLA)-B27-associated diseases such as acute anterior uveitis (AAU) and ankylosing spondylitis (AS) remains poorly understood, though Gram-negative bacteria and subclinical bowel inflammation are strongly implicated. Accumulating evidence from animal models and clinical studies supports several hypotheses, including HLA-B27-dependent dysbiosis, altered intestinal permeability, and molecular mimicry. However, the existing literature is hampered by inadequate studies designed to establish causation or uncover the role of viruses and fungi. Moreover, the unique disease model afforded by AAU to study the gut microbiota has been neglected. This review critically evaluates the current literature and prevailing hypotheses on the link between the gut microbiota and HLA-B27-associated disease. We propose a new potential role for HLA-B27-driven altered antibody responses to gut microbiota in disease pathogenesis and outline recommendations for future well-controlled human studies, focusing on AAU.

Morphology of the Trabecular Meshwork and Schlemm's Canal in Posner-Schlossman Syndrome.

Purpose: The purpose of this study was to investigate trabecular meshwork (TM) and Schlemm's canal (SC) morphology in Posner-Schlossman syndrome (PSS). Methods: Forty-five patients with PSS were recruited. TM thickness and length as well as SC area and diameter of both affected and fellow eyes were assessed using swept-source optical coherence tomography. Results: TM thickness (108.24 ± 28.29 µm vs. 89.36 ± 25.82 µm, P = 0.014), SC area (6010.90 ± 1287.54 µm2 vs. 5445.69 ± 1368.89 µm2, P = 0.003), and SC diameter (239.38 ± 60.17 µm vs. 217.76 ± 60.79 µm, P = 0.010) were significantly greater in the affected eyes. Furthermore, TM thickness (113.32 ± 30.03 µm vs. 89.00 ± 26.99 µm, P = 0.046), SC area (6216.32 ± 1267.87 µm2 vs. 5476.40 ± 1390.15 µm2, P = 0.001), and SC diameter (246.82 ± 64.12 vs. 212.53 ± 64.29 µm, P = 0.001) were significantly greater in the affected eyes than in the fellow eyes in the ocular hypertension (OHT) subgroup (affected eye with intraocular pressure [IOP] > 21 mm Hg). However, those differences were not noted in the ocular normal tension (ONT) subgroup (affected eye with IOP ≤ 21 mm Hg, all P > 0.05). Conclusions: TM edema might play a role in the IOP elevation in PSS. The edematous TM could make controlling IOP of the affected eyes difficult. When TM edema is relieved, IOP of the affected eyes can reduce to normal spontaneously or with IOP-lowing medications.

Intraocular dendritic cells characterize HLA-B27-associated acute anterior uveitis.

Uveitis describes a heterogeneous group of inflammatory eye diseases characterized by infiltration of leukocytes into the uveal tissues. Uveitis associated with the HLA haplotype B27 (HLA-B27) is a common subtype of uveitis and a prototypical ocular immune-mediated disease. Local immune mechanisms driving human uveitis are poorly characterized mainly due to the limited available biomaterial and subsequent technical limitations. Here, we provide the first high-resolution characterization of intraocular leukocytes in HLA-B27-positive (n = 4) and -negative (n = 2) anterior uveitis and an infectious endophthalmitis control (n = 1) by combining single-cell RNA-sequencing with flow cytometry and protein analysis. Ocular cell infiltrates consisted primarily of lymphocytes in both subtypes of uveitis and of myeloid cells in infectious endophthalmitis. HLA-B27-positive uveitis exclusively featured a plasmacytoid and classical dendritic cell (cDC) infiltrate. Moreover, cDCs were central in predicted local cell-cell communication. This suggests a unique pattern of ocular leukocyte infiltration in HLA-B27-positive uveitis with relevance to DCs.

Uveitis is a form of inflammation in the eye. It can occur in response to infection, or when the immune system mistakenly attacks the eye, in what is known as autoimmune uveitis. In approximately 80 percent of cases, the front part of the eye is affected. During an inflammatory episode, the liquid inside the front part of the eye fills with immune cells, but the nature of these cells remains unknown. This is because uveitis is rare, and doctors cannot routinely take samples from inside the eyes of affected individuals to diagnose the disease. This lack of samples makes research into this disease challenging. There are two main groups of immune cells that could be responsible for uveitis: myeloid cells and lymphoid cells. Myeloid cells form the first line of immune defense against infection by non-specifically attacking and removing pathogens . Lymphoid cells form the second line of immune defense, attacking specific pathogens. Lymphoid cells also have long-term memory, meaning they can 'remember' previous infections and fight them more effectively. Lymphoid cells receive instructions from a type of myeloid cell called a dendritic cell about what to attack. Dendritic cells relay their instructions to lymphoid cells using molecules called human leukocyte antigens (HLA). Autoimmune uveitis affecting the front part of the eye is common in individuals with an HLA type called HLA-B27, suggesting that communication between dendritic and lymphoid cells plays an important role in this type of inflammation. To make the most of limited patient samples, Kasper et al. used single cell techniques to examine the immune cells from the fluid inside the eye. Six samples came from people with autoimmune uveitis, and one from a person with an eye infection. The infection sample contained mainly myeloid cells that might attack bacteria responsible for the infection. In contrast, the autoimmune uveitis samples contained mainly lymphoid cells. Of these samples, four were from individuals with the gene that codes for the HLA-B27 molecule. These samples had a unique pattern of immune cells, with more dendritic cells than the samples from individuals that did not have this gene. This study included only a small number of individuals, but it shows that analysing single immune cells from the eye is possible in uveitis. This snapshot could help researchers understand the local immune response in the eye, and find an optimal treatment.

Role of MCP-1 and IL-8 in viral anterior uveitis, and contractility and fibrogenic activity of trabecular meshwork cells.

The inflammatory chemokines, monocyte chemoattractant protein (MCP)-1 and IL-8, are produced by normal trabecular meshwork cells (TM) and elevated in the aqueous humor of primary open angle glaucoma (POAG) and hypertensive anterior uveitis associated with viral infection. However, their role in TM cells and aqueous humor outflow remains unclear. Here, we explored the possible involvement of MCP-1 and IL-8 in the physiology of TM cells in the context of aqueous outflow, and the viral anterior uveitis. We found that the stimulation of human TM cells with MCP-1 and IL-8 induced significant increase in the formation of actin stress fibers and focal adhesions, myosin light chain phosphorylation, and the contraction of TM cells. MCP-1 and IL-8 also demonstrated elevation of extracellular matrix proteins, and the migration of TM cells. When TM cells were infected with HSV-1 and CMV virus, there was a significant increase in cytoskeletal contraction and Rho-GTPase activation. Viral infection of TM cells revealed significantly increased expression of MCP-1 and IL-8. Taken together, these results indicate that MCP-1 and IL-8 induce TM cell contractibility, fibrogenic activity, and plasticity, which are presumed to increase resistance to aqueous outflow in viral anterior uveitis and POAG.

Triggering factors associated with a new episode of recurrent acute anterior uveitis.

To identify triggering factors for the next inflammatory episode of recurrent acute anterior uveitis (RAAU), a 1:1 case-control study was conducted. We interviewed RAAU patients with recent acute anterior uveitis attack and quiescent controls for their information during a previous month using Srithanya Stress Test (ST-5) and questionnaires about potential triggering factors. Asymptomatic controls were matched for age (± 5 years), sex, and HLA-B27. There were 39 pairs of cases and controls. Patients who recently experienced a uveitis attack demonstrated higher mean ST-5 scores (3.7 ± 2.9 vs 0.7 ± 1.1) and shorter sleep time (6.3 ± 1.4 vs 7.4 ± 0.7 h per day) compared with their controls. In the multivariate conditional logistic regression analysis, ST-5 score ≥ 3 (OR 9.07, 95% CI 1.14-72.16, p = 0.037) and sleep time < 7 h per day (OR 12.12, 95% CI 1.37-107.17, p = 0.025) were more likely to trigger a uveitis attack in RAAU accounted for patients' age, sex, HLA- B27 positivity, and presence of concurrent anti-inflammatory drugs for co-existing diseases. Other suspected triggering factors were not found to have any significant association. In short, stress and inadequate sleep may lead to the future episode of acute anterior uveitis in RAAU. Both physical and emotional stress management should be advised to RAAU patients to minimize recurrences and further complications.

Clinical characteristics and prognostic factors in hypertensive anterior uveitis diagnosed with polymerase chain reaction.

Aim of the study is to report the clinical characteristics and prognostic factors in hypertensive anterior uveitis (AU) diagnosed with multiplex polymerase chain reaction (PCR). Eighty-eight eyes of 88 patients with hypertensive AU were enrolled from 2015 to 2019 in a tertiary center in South Korea. All patients underwent multiplex PCR that was performed using aqueous humor samples collected at first visit to detect the DNA of six herpesviruses. Twenty-eight (31.8%) eyes were PCR positive. Herpes simplex virus was found in 6 (6.8%) eyes, varicella-zoster virus in 7 (8.0%) eyes, cytomegalovirus in 14 (15.9%) eyes, and Epstein-Barr virus in 1 (1.1%) eye. On multivariate regression analysis, PCR positivity was significantly associated with coin-shaped keratic precipitates (odds ratio (OR) = 6.01, P = 0.044). Recurrence and final visual acuity were significantly associated with a presumed diagnosis of viral endotheliitis (OR = 21.69, P = 0.04 and OR = 6.3, P = 0.004, respectively). This study showed the importance of PCR positivity, suggesting that identification of the virus through active PCR testing could affect the course, treatment, and prognosis of hypertensive AU.

Similarities in clinical course and outcome between juvenile idiopathic arthritis (JIA)-associated and ANA-positive idiopathic anterior uveitis: data from a population-based nationwide study in Germany.

BACKGROUND: To analyze whether ANA-positive idiopathic anterior uveitis differs from JIA-associated uveitis concerning clinical course, response to treatment, and disease outcome. METHODS: Prospective study of the National Paediatric Rheumatological Database (NPRD) including its uveitis add-on module from the years 2002 to 2016. Cross-sectional data from the years 2002 to 2016 were analyzed. Patients with JIA-associated uveitis and with ANA-positive idiopathic anterior uveitis were included and the disease manifestation investigated in terms of uveitis characteristics and disease course. RESULTS: Of the total cohort of 34,458 patients enrolled in the NPRD, including 3551 patients with uveitis, those with detailed uveitis documentation were taken into account: 62 ANA-positive patients with idiopathic anterior uveitis (group 1), 688 patients with initial uveitis diagnosis after JIA onset (group 2), and 61 JIA patients with initial uveitis diagnosis before arthritis onset (group 3). Anterior uveitis was documented in 100%, 94%, and 80% of patients and with insidious onset of uveitis flare in 50%, 70.9%, and 56.1% each in groups 1, 2, and 3, respectively. Use of topical or systemic corticosteroids and conventional synthetic or biological DMARDs did not significantly differ between the patient groups, either at the initial or the 2-year follow-up (2-FU) visits (mean 2 years, each p > 0.05). At 2-FU, uveitis inactivity was achieved in 64.7%, 55.8%, and 61.5% of patients in groups 1, 2, and 3 (p > 0.05). Uveitis-related complications were more frequent at the initial visit and at 2-FU in groups 1 and 3, as compared to group 2. CONCLUSIONS: ANA-positive idiopathic uveitis and JIA-associated uveitis do not significantly differ concerning clinical course of uveitis, treatment, and response to corticosteroids and DMARDs.

Aqueous cytokine levels in four common uveitis entities.

To investigate aqueous cytokine profiles in acute anterior uveitis (AAU), Fuchs' syndrome, Vogt-Koyanagi-Harada (VKH) disease and Behcet's disease (BD), we assayed the concentrations of 17 cytokines by multiplex immunoassay in aqueous humor (AqH) collected during cataract surgery from 24 AAU, 29 Fuchs' syndrome, 29 VKH disease, 30 BD and 30 senile cataract control patients. Aqueous cytokine levels were compared between the five groups and analysed by logistic regression. Cytokine levels were then compared between uveitis patients who underwent cataract surgery within 3 months and those who underwent this surgery more than 3 months after complete control of intraocular inflammation. The results showed that aqueous levels of interferon (IFN)-γ, monocyte chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-1ß and tumour necrosis factor (TNF)-α levels in AqH from patients with Fuchs' syndrome were significantly higher than those in the other four groups. Using multivariate analysis, MIP-1ß was found to be significantly associated with Fuchs' syndrome. There was no difference in aqueous cytokine levels between cases having cataract surgery within 3 months compared to those after 3 months of complete control of their intraocular inflammation. The current study shows that Chinese patients with Fuchs' syndrome appear to have a specific cytokine profile. MIP-1ß is an important chemokine in the intraocular environment of Fuchs' syndrome. Aqueous cytokine profiles support the performance of cataract surgery in uveitis within 3 months after intraocular inflammation control.

Bilateral Anterior Uveitis in a Northern Saw-whet Owl (Aegolius acadicus) With a Metastatic Pectoral Malignant Mesenchymoma.

A captive, adult, male northern saw-whet owl (Aegolius acadicus) was examined for blepharospasm of the left eye. The owl was diagnosed with bilateral anterior uveitis and a corneal ulceration in the left eye. It was treated with oral and topical nonsteroidal anti-inflammatory medications and a topical antibiotic. Multiple recheck examinations and medication adjustments were performed over the next 4 months, at the end of which time the bilateral anterior uveitis was controlled with a topical nonsteroidal anti-inflammatory applied 3 times per week to both eyes. The owl was re-examined 2 months later after 2 suspected neurologic episodes. On physical examination, the owl was quiet and had difficulty standing and ambulating. Five firm multilobular and immobile masses were identified overlying the pectoral muscle and sternum. Fine-needle aspiration from 1 mass revealed neoplastic cells consistent with a sarcoma. The owl was euthanatized. On the basis of results of histopathologic examination, the mass was diagnosed as a pleomorphic spindle cell sarcoma with features of rhabdomyosarcoma, liposarcoma, and osteosarcoma. Numerous tumor cells were immunopositive for myoglobin and desmin, indicating striated muscle origin. Although a metastatic lesion was present in 1 adrenal gland, lesions of inflammation or neoplasia were absent in either eye on histopathologic examination. This report describes an apparent ocular manifestation of systemic disease in an avian species with clinically diagnosed recurrent anterior uveitis.

Supposed endogenous endophthalmitis caused by Serratia marcescens in a cat.

An 8-year-old male neutered domestic shorthair cat was presented for evaluation of acute respiratory distress. Respiratory auscultation revealed a diffuse and symmetric increase in bronchovesicular sounds. Thoracic radiographs showed a diffuse unstructured interstitial pulmonary pattern with multifocal alveolar foci. Despite an aggressive treatment with supportive care, including oxygenotherapy and systemic antibiotics, progressive respiratory distress increased. Three days after the presentation, acute anterior uveitis was noticed on left eye. Ophthalmic examination and ocular ultrasonography revealed unilateral panuveitis with ocular hypertension. The right eye examination was unremarkable. Cytological examination of aqueous humor revealed a suppurative inflammation. Serratia marcescens was identified from aqueous humor culture. Primary pulmonary infection was suspected but was not confirmed as owners declined bronchoalveolar lavage. Active uveitis resolved and cat's pulmonary status improved after appropriate systemic antibacterial therapy. Vision loss was permanent due to secondary mature cataract. To the best of authors' knowledge, this is the first report of endogenous bacterial endophthalmitis secondary to S. marcescens infection in a cat.

Ophthalmologic Manifestation of Inflammatory Bowel Disease: A Review.

In patients with inflammatory bowel disease (IBD), ocular extraintestinal manifestations (EIM) are less common than EIM of other systems, but they are clinically important because they can lead to complications that can cause catastrophic damage to the visual acuity and ocular structure. Anterior uveitis and episcleritis are the most common ocular EIM. Involvement of the orbit, posterior segment, and optic nerve can also occur. A variety of treatments are available ranging from topical steroids to systemic immunosuppressive therapies. The treatment of IBD is also essential if the activity of inflammatory bowel disease affects the ocular symptoms.

Determination of a No Observable Effect Level for Endotoxin Following a Single Intravitreal Administration to Cynomolgus Monkeys.

Purpose: To characterize the inflammatory response and determine the no-observable-effect level (NOEL) in cynomolgus monkey eyes after intravitreal (ITV) injection of endotoxin. Methods: The inflammatory response to endotoxin was assessed in a single-dose study in monkeys at doses of 0.01 to 0.51 endotoxin units (EU)/eye. Tolerability was assessed by clinical ophthalmic examinations, intraocular pressure measurements, fundus color photography, optical coherence tomography, and anatomic pathology. Results: ITV injection of endotoxin at ≥0.04 EU/eye resulted in a dose-related anterior segment inflammatory response. No aqueous flare or cell was noted in the 0.01 EU/eye dose group. A more delayed posterior segment response characterized by vitreous cell was observed beginning on day 5, peaking on day 15, and decreasing in some groups. Microscopic findings of mononuclear cell infiltrates in the vitreous were observed in eyes given ≥0.21 EU/eye. Conclusion: The NOEL for ITV endotoxin in cynomolgus monkeys was 0.01 EU/eye, suggesting that this species is as sensitive as rabbits to the effects of endotoxin. The vitreous cavity also appears more sensitive to endotoxin than the anterior segment/aqueous chamber. Overall, the magnitude of the inflammatory response at ≥0.04 EU/eye suggests that dose-response curve in monkeys is steeper than in rabbits. These data highlight the importance of assessing endotoxin level in ITV formulations, as levels as low as 0.04 EU/eye may confound the safety evaluations of ITV therapeutics in cynomolgus monkeys.

Evaluation of choroidal parameters in eyes at the first onset of acute anterior uveitis.

BACKGROUND: Little is known about choroidal involvement in anterior uveitis. The aim of our study was to evaluate changes in choroidal thickness and volume in eyes with acute anterior uveitis (AAU) using enhanced depth imaging-optical coherence tomography (EDI-OCT) at baseline and after treatment, which were compared with healthy fellow eyes. METHODS: For the study, 35 individuals with unilateral acute AAU at the first onset were enrolled. Subfoveal thickness and choroidal volume were measured with EDI-OCT in nine Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields before and after the completion of treatment. Moreover, axial length measurements of both eye bulbs were determined by optical biometry. RESULTS: No statistically significant differences in choroidal thickness or choroidal volume were detected between AAU eyes at baseline and after treatment and fellow eyes. Positive correlations between the values of anterior chamber flare and absolute CT changes in both temporal and inferior ETDRS fields, as well as in superior outer ring were detected. Negative correlations between age and both choroidal thickness and choroidal volume were detected in AAU eyes at baseline and after treatment, as well as in fellow eyes. CONCLUSIONS: Evaluation of the choroid with EDI-OCT does not appear to be a reliable tool for the treatment monitoring of eyes with anterior uveitis.

Growth hormone-releasing hormone receptor mediates cytokine production in ciliary and iris epithelial cells during LPS-induced ocular inflammation.

The receptor for growth hormone-releasing hormone (GHRH-R) has been shown to upregulate specifically in the ciliary and iris epithelial cells and infiltrating cells in the aqueous humor in a rat model of acute anterior uveitis. Treatment with GHRHR-R antagonist alleviates significantly these inflammatory responses. Herein we investigated whether the ciliary and iris epithelial cells can respond directly to lipopolysaccharide (LPS) without the influences of circulating leukocytes to produce inflammatory mediators through a GHRH-R mediated mechanism. In explant cultures of rat ciliary body and iris, LPS caused a substantial increase of GHRH-R in 24 h. Immunohistochemistry showed a localization of TLR4, the receptor for LPS, and an elevated expression of IL-6 and IL-1ß in ciliary and iris epithelial cells after LPS treatment. LPS also elevated the level of IL-1ß, IL-6, and iNOS and increased secretion of IL-1ß and IL-6 from the explants. The GHRH-R antagonist, MIA-602, suppressed the elevated expression of IL-1ß and IL-6, and reduced the release of IL-6. Such effects were not seen for the GHRHR agonist, MR-409. When co-cultured with leukocytes, expression of GHRH-R in the ocular explants was further enhanced during LPS treatment. Our results demonstrate a direct action of LPS on ciliary and iris epithelial cells to produce pro-inflammatory factors through a GHRH-R mediated mechanism, and suggest a role of these epithelial cells, in addition to the resident antigen presenting cells, in immune surveillance of the eye. Infiltrating leukocytes may enhance these inflammatory responses by regulating GHRH-R in ciliary and iris epithelial cells, in addition to their functions of synthesizing proinflammatory cytokines.

Inhibitory role of transforming growth factor ß2 in experimental autoimmune anterior uveitis.

PURPOSE: Experimental autoimmune anterior uveitis (EAAU) is a clinically relevant animal model for human idiopathic anterior uveitis (IAU). The role of the immunomodulator transforming growth factor ß2 (TGF-ß2) in EAAU pathology is unknown. In this study, we investigated the regulatory role of TGF-ß2 in EAAU. METHODS: EAAU was induced in male Lewis rats by footpad injection of melanin-associated antigen (MAA). TGF-ß2 was administered intravenously (iv) in MAA-sensitized rats during the induction of EAAU, or after the clinical onset of uveitis. MAA-sensitized rats injected similarly with an equal volume of PBS served as control. Animals were examined daily between days 7 and 30 post-injection for the clinical signs of uveitis using slit lamp biomicroscopy. Animals were sacrificed at various time points and eyes were harvested for histological analysis to assess the course and severity of inflammation. For histopathological analysis, paraffin sections of harvested eyes were stained with hematoxylin and eosin. Popliteal lymph nodes (LNs) were used for CD4+CD25+FoxP3+ T regulatory (Tregs) population analysis and for CD4+ T cell proliferation assay. RESULTS: Administration of recombinant TGF-ß2 during the early stages of EAAU prevented the induction of uveitis. Compared to PBS, the presence of TGF-ß2 in the cell culture significantly (p < 0.05) inhibited the proliferation of CD4+ T cells in response to MAA. In MAA-sensitized Lewis rats, iv treatment with recombinant TGF-ß2 resulted in significantly (p < 0.05) increased percentage of Tregs compared to animals treated similarly with PBS. Thus, TGF-ß2 inhibited the induction of EAAU by inhibiting CD4+ T cell proliferation and increasing the number of Tregs. Injection of TGF-ß2 in rats with active EAAU resulted in diminished disease activity. Unfortunately, this treatment did not lead to the early resolution of EAAU. CONCLUSIONS: TGF-ß2 plays a critical role in regulation of intraocular inflammation in EAAU. Findings reported in this study improve our understanding of immunopathology of IAU and suggest that recombinant TGF-ß2 may be a promising therapeutic agent for human IAU.

Ophthalmologic findings associated with Rhodococcus equi bronchopneumonia in foals.

OBJECTIVE: To describe ocular findings associated with Rhodococcus equi bronchopneumonia in foals, and to determine whether severity of the ocular lesions is related with outcome. ANIMALS STUDIED: Foals diagnosed with R equi infection at the VTH-UAB from January 2002 to December 2017. PROCEDURE: Rhodococcus equi infection was diagnosed by means of clinical signs, radiographic/ultrasonographic findings, and/or positive culture. In all the foals, a complete ophthalmic examination by a boarded ophthalmologist was performed and ocular signs were recorded and graded (0-4). RESULTS: Thirty-nine foals were included in the study, from which 12 showed signs of bilateral anterior uveitis (30.8%). Among these, three foals were classified as mildly uveitis-affected (MUA:7.7%) and nine as severely uveitis-affected (SUA:23.1%). Five SUA foals showed green aqueous flare (5/9;55.5%). Despite the systemic treatment, 9/39 sick foals died (23.1%), the fatality rate being different between groups: SUA (4/9;44.4%), MUA (0/3; 0%) and nonuveitis-affected foals (5/27;18.5%). Among SUA foals, only one with green aqueous flare died (1/5;20%). CONCLUSION: Bilateral anterior uveitis is highly prevalent in foals with R equi pneumonia (30.8%). The severity of anterior uveitis might be considered a nonsurvival prognostic factor and, until proven otherwise, green aqueous flare could be taken as a strongly suggestive ocular sign of the disease. Findings of this study remark the clinical relevance of performing a complete ophthalmic examination in sick foals, in order to help in the diagnosis and prognosis of uveal diseases, as well as to guaranteeing visual soundness.

Instrument-based tests for measuring anterior chamber cells in uveitis: a systematic review protocol.

BACKGROUND: Uveitis describes a group of inflammatory conditions affecting the eye. The ability to monitor inflammatory changes in anterior uveitis is crucial in clinical practice for making treatment decisions and in clinical trials for testing therapeutic agents. The current standard for quantifying anterior segment inflammation is clinical slit-lamp examination findings classified using the Standardisation of Uveitis Nomenclature (SUN) grading system. Such clinical grading systems rely on a subjective estimation using the slit lamp and are often non-linear and non-continuous scales, with large increases in cell count between each grade. Novel instrument-based technologies have emerged over the last few decades, which can provide objective and quantifiable measurements. This review will evaluate the reliability of such technologies and their level of agreement with anterior chamber (AC) cell count using clinical slit-lamp examination. METHODS: Standard systematic review methodology will be used to identify, select and extract data from studies that report the use of any instrument-based technology in the assessment of AC cells. Searches will be conducted through bibliographic databases (MEDLINE, EMBASE and Cochrane Library), clinical trial registries and the grey literature. No restrictions will be placed on language or year of publication. The outcomes of interest are the correlation of index test measurements of AC cells with clinical grading systems using slit-lamp examination and the reliability of each index test identified. Quality assessment will be undertaken using QUADAS2. Degree of correlation between the index and reference test measures will be pooled and meta-analysed if appropriate. DISCUSSION: A number of instrument-based tools are available for measuring AC cells. This review will evaluate the technologies available and measure the level of correlation of these alternative methods with clinical grading systems as well as their performance in reliability and repeatability. The findings of this review will identify those objective, instrument-based technologies which show good utility for measuring AC cells in a quantifiable way and which warrant further exploration for their sensitivity and reliability over the current standard. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017084156 (Liu X, Moore DJ, Denniston AK). Instrument-based tests for measuring anterior chamber (AC) cells in uveitis: a systematic review. 2017). Study screening stage is complete. Data extraction stage has not yet commenced.

Evaluation of changes in retinal and choroidal thickness using spectral domain optical coherence tomography in unilateral non granulomatous acute anterior uveitis.

PURPOSE: To assess retinal and choroidal thickness changes in eyes with a first episode of unilateral non granulomatous acute anterior uveitis (AU). METHODS: Thirty-one patients with acute unilateral non granulomatous AU who had undergone spectral domain optical coherence tomography (SD-OCT) of both eyes were included in this retrospective study. Retinal thickness (RT) as defined by the Early Treatment Diabetic Retinopathy Study (ETDRS) and subfoveal choroidal thickness (SFCT) obtained by SD-OCT were recorded. Healthy fellow eyes of the patients served as the control. RESULTS: A significant thickening in 1mm of ETDRS subfield and in subfoveal choroid was observed in eyes with acute AU when compared with the unaffected fellow eyes (P=0.005 and P<0.00001, respectively). RT and SFCT of affected eyes did not show a significant difference in terms of HLA-B27 antigen presence or absence (P>0.05, for all). CONCLUSIONS: Significant posterior segment changes were detected in eyes with acute unilateral non granulomatous AU.