HLA-A29 Birdshot Retinochoroiditis in Its 5th Decade: Selected Glimpses into the Intellectual Meanderings and Progresses in the Knowledge of a Long-Time Misunderstood Disease

Efficacy and safety of abatacept to treat active birdshot uveitis: a prospective open label interventional proof-of-concept trial

BACKGROUND/AIMS

Birdshot uveitis (BU) is a chronic autoimmune posterior uveitis, mostly affecting middle-aged Caucasians. There is a strong association with HLA-A29 and T-cell activation. Safety and efficacy of abatacept, an inhibitor of T-cell costimulation, is tested in active BU.

METHODS

Fifteen patients with active BU were treated with monotherapy of weekly subcutaneous injections of abatacept 125 mg/mL. Time-to-treatment failure was evaluated as a primary outcome. The secondary objective was to evaluate the utility of different outcome measures to monitor disease activity. Safety was evaluated by adverse event reporting and serial blood analyses.

RESULTS

At the year-1 endpoint, there was significant improvement in vitreous haze grade (p=0.0014), central choroidal thickness (CCT) (p=0.0011), Fluorescein Angiography (FA) Score (p=0.0014), Indocyanine Green Angiography (ICGA) Score (p<0.001) and total dual FA-ICGA Score (p<0.001). Best corrected visual acuity (BCVA) (p=0.8354) and central retinal thickness (CRT) (p=0.3549) did not change significantly. There were no serious adverse events reported. In total, 4 out of 15 patients left the trial during year 1 of whom 2 experienced treatment failure.

CONCLUSIONS

Abatacept is very efficacious to treat both retinal vasculitis and choroiditis in patients with BU and is well tolerated. BCVA and CRT are inadequate to monitor disease activity. On the other hand, CCT is a promising non-invasive tool to detect treatment response in early active BU and dual FA-ICGA Score is very helpful to evaluate retinal vasculitis and choroiditis quantitatively.

TRIAL REGISTRATION NUMBER

NCT03871361.

Wide Field Optical Coherence Tomography and Optical Coherence Tomography Angiography in Uveitis

BACKGROUND

We review the current literature on the use of wide-field optical coherence tomography (OCT) and wide-field optical coherence tomography angiography (OCTA) in different uveitic phenotypes as well as various sequelae of uveitis and discuss the limitations of this evolving technology.

MAIN BODY

Current consensus guidelines on nomenclature in wide-field OCT and OCTA are described. The specific utility of wide-field OCT and OCTA in assessment of the retina and choroid using different en-face and cross-sectional slabs in various inflammatory diseases is reviewed. Furthermore, we discuss widefield OCT and OCTA in assessment of retinal ischemia and its limitations in assessing retinal vascular leakage.

CONCLUSION

Wide-field OCT and OCTA deliver more sensitive measures of inflammation. With continued advancement in both hardware technology and software processing, these modalities will allow for more accurate assessment of uveitis, better understanding of disease mechanisms, and precise monitoring of treatment response.

Long-Term Outcomes of Birdshot Chorioretinopathy Treated with Corticosteroids: A Case Reports

PURPOSE

To report the progression of patients diagnosed with birdshot chorioretinopathy (BSCR) initially treated with corticosteroids.

METHODS

We included 39 BSCR patients that were followed for ≥1 year. We analyzed their progression under treatment after 1, 3, 6 months, 1 year, and at the end of follow-up. In order to determine the efficiency of initial loading doses, patients were classified into two groups according to their initial treatment: methylprednisolone followed by prednisone (n = 28) and prednisone alone (n = 11).

RESULTS

At the end of follow-up, 31/39 (79.5%) patients had reached inflammation control. Thirteen out of 28 (46.4%) and 6/11 (54.5%) patients were treated exclusively with corticosteroids, and 18/19 (94.7%) of them had reached inflammation control at the end of follow-up; their mean (range) corticosteroid dose was 3.5 (0-10) mg/day.

CONCLUSIONS

We found that the prolonged corticosteroid therapy treatment strategy resulted in inflammation control in half of BSCR patients. This control was maintained with low doses of cortisone, usually <5 mg/day.

Benefits and Limitations of OCT-A in the Diagnosis and Follow-Up of Posterior Intraocular Inflammation in Current Clinical Practice: A Valuable Tool or a Deceiver?

Purpose: Optical coherence tomography angiography (OCT-A) has been applied to uveitis and intraocular inflammation since its availability after 2014. The imaging of retinal and choroidal vascularization without the use of dyes was a major development and represented a potentially valuable tool in ocular research. In addition to such use, OCT-A is often put forward as being able to potentially replace invasive methods needing dye injection, such as fluorescein angiography (FA) and indocyanine green angiography (ICGA). The aim of this review was to establish whether OCT-A was sufficiently useful in everyday routine clinical practice to monitor disease evolution and to perform treatment adjustments to the extent that it could reliably replace the standard dye methods. Methods: Selective literature review and analysis of own data and experience. Results: OCT-A is a technologically high-grade imaging modality allowing to analyze retinal circulation in inflammatory diseases of the posterior pole with a high sensitivity useful for research purposes. However, there is no evidence that it reaches equal effectiveness in the routine management of posterior uveitis involving the retina. OCT-A is unable to show leakage. In choriocapillaritis involving pre-capillary vessels, it shows capillary drop-out but does not seem to have an advantage over ICGA except that it can be repeated easily, not being invasive, and so allows a closer follow-up. It is, however, less useful in end-choriocapillary non-perfusion, such as in MEWDS. For choroidal stromal inflammation, OCT-A is ill-suited as it only shows inconsistent secondary circulatory changes produced by choroidal foci. OCT-A seems to be useful in the diagnosis and follow-up of inflammatory chorioneovascularisation (iCNV), although dye exams are more precise in showing the activity of the iCNV. Conclusion: In summary, OCT-A is a very sensitive modality for the retinal circulation in uveitis for research purposes; it is sometimes useful for close follow of choriocapillary drop-out but not in end-capillary non-perfusion. Its use for monitoring purposes in stromal choroiditis, however, is questionable. Its claim to possibly replace classical angiographic work-up for the practical management of posterior uveitis is largely overrated.

Birdshot Chorioretinopathy: A Review

Birdshot chorioretinopathy (BSCR) is a bilateral chronic inflammation of the eye with no extraocular manifestations. BSCR affects middle-aged individuals from European descent and is strongly associated with the human leucocyte antigen (HLA)-A29 allele. The immune mechanisms involved are not fully understood, but recent advances have shown the role of Endoplasmic Reticulum Aminopeptidase 2 (ERAP2) in disease pathogenesis. Multimodal imaging, including fluorescein angiography, indocyanine angiography, fundus autofluorescence, and optical coherence tomography, are useful in confirming the diagnosis and monitoring disease activity. Visual field testing is also important to assess the disease progression. To date, there is no consensus for optimal treatment regimen and duration. Local and systemic corticosteroids can be used for short periods, but immunosuppressive or biological therapies are usually needed for the long-term management of the disease. Here, we will review publications focused on birdshot chorioretinopathy to give an update on the pathophysiology, the multimodal imaging, and the treatment of the disease.

Mechanisms, Pathophysiology and Current Immunomodulatory/Immunosuppressive Therapy of Non-Infectious and/or Immune-Mediated Choroiditis

Non-infectious choroiditis comprises immune-mediated diseases resulting from diverse pathophysiological mechanisms. These conditions are sub-divided into two main groups, (1) diseases of the choriocapillaris and (2) diseases of the choroidal stroma. The purpose of this study is to expose the pathophysiology of the most common diseases of both these groups and recommend the optimal immunomodulatory/immunosuppressive therapy of each analyzed condition based on literature data and data from our own centers. Material and Methods: Narrative review. In the group of choriocapillaritis entities or primary inflammatory choriocapillaropathies (PICCPs) including multiple evanescent white dot syndrome (MEWDS), acute posterior multifocal placoid pigment epitheliopathy (APMPPE), idiopathic multifocal choroiditis (MFC) and serpiginous choroiditis (SC), as well as secondary choriocapillaritides including acute syphilitic posterior multifocal placoid chorioretinitis (ASPMPC) and tuberculosis-related SC (TB-SC), were analyzed. In the group of stromal choroidites, HLA-A29 birdshot retinochoroiditis (BRC) and Vogt-Koyanagi-Harada (VKH) disease were included. For each entity a literature search, in the PubMed database, on treatment was performed and analyzed and the therapeutic attitudes of our own centers were presented. Management of immune-mediated choroiditis implies vigorous immunosuppressive therapy given in a prompt and prolonged fashion in most of these entities.

Clinicopathology of non-infectious choroiditis: evolution of its appraisal during the last 2-3 decades from "white dot syndromes" to precise classification

Choroidal imaging investigation techniques were very limited until 2–3 decades ago.

Fluorescein angiography (FA) was not suited for the analysis of the choroidal compartment and B-scan ultrasonography did not provide enough accuracy. It was on this background that a purely phenomenological approach was attempted to classify these choroiditis diseases by regrouping them under the vague potpourri term of “white dot syndromes”. With the availability of precise investigational modalities of choroidal inflammation or choroiditis-induced lesions, such as indocyanine green angiography (ICGA), spectral domain optical coherence tomography (SD-OCT) and enhanced depth imaging optical coherence tomography (EDI-OCT) it became possible to better classify these diseases based on clinico-pathological mechanisms rather than on purely phenomenological observation.

Recently OCT-angiography has implemented the armamentarium of diagnostic techniques possibly also contributing to the classification of choroidal inflammatory diseases.

Based on pioneering pragmatism, the aim of this article was to give a clear classification of non-infectious choroiditis. Thanks to new imaging investigations of the choroid, it is now possible to classify and understand the diverse clinicopathological mechanisms in the group of non-infectious choroiditis entities.