Birdshot retinochoroidopathy: pathophysiology, diagnosis and treatment

ABSTRACT

Introduction: Birdshot Retinochoroidopathy (BSRC) typically affects Caucasian middle-aged patients and is strongly associated with the human leukocyte antigen, HLA-A29. The pathogenesis is not completely understood, but retinal autoimmunity related to T cells are involved. Diagnosis is made from clinical exam and ocular imaging. Early initiation of corticosteroid-sparing systemic immunomodulatory therapy (IMT) with periodic diagnostic testing to direct therapy, is the current recommendation, as visual acuity is inadequate to monitor progression. Humanized recombinant monoclonal antibodies, as well as intravitreal and surgical steroid implants have been used effectively at least transiently in refractory patients.

Areas covered: In this article, the authors review and present current literature on the pathophysiology, diagnosis and treatment of BSRC.

Expert opinion: BSRC is a vision-threatening disease. Control of intraocular inflammation is essential for good visual outcomes. With the known complications of steroids and their transient effectiveness, these medications are best reserved for acute flare management. The authors’ first therapeutic choice is the combination of cyclosporine and mycophenolate mofetil, with adjustments in medication and dosage based on inflammation status at follow-up evaluations. Once remission is achieved on medications, we strongly advocate to maintain the treatment for at least 2 years before tapering therapy.

KEYWORDS:

• Birdshot retinochoroidopathy
• immunomodulatory therapy
• T-cell-mediated autoimmuny
• uveitis

Article highlights

• BSRC is a vision-threatening disease, but visual acuity is usually unaffected in the early disease stage. The patient often experienced visual disturbance, such as photopsias, nyctalopia, color desaturation and floaters.

• The exact pathogenesis of BSRC is still unknown. It is believed to be an autoimmune disease. Almost all patients with BSRC are human leukocyte antigen (HLA-A29) carriers and this is the highest known association of any human disease.

• The diagnosis of BSRC is still based on clinical findings (typical fundus hypopigmented lesions), but the modern diagnostic modalities including fluorescein angiography, indocianine green angiography, optical coherence tomography, vidual field and elettroretinography, could help in early recognition of the disease. Serology is essential to rule out other causes of posterior uveitis, especially infection.

• Tha visual acuity id not a good parameter for the follow-up. A complete ocular examination, including fluorescein angiography, indocianine green angiography, optical coherence tomography, vidual field and elettroretinography, every 6 months may be a good follow-up protocol to recognize subtle recurrences and evaluate the effectiveness of the therapy.

• Steroid monotherapy is not effective on long-term control of BSRC. An early steroid-spering immunosuppressive therapy is essential for the control of inflammation. Authors’ first line treatmnt is the combination of cyclosporine and mycophenolate mofetil.

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Declaration of interest

CS foster disclosed consultancies with Aldeyra Therapeutics, Bausch & lomb Surgical, Inc, Eyegate Pharma, Novartis, pSivida and Xoma. Grants or grants pending with Alcon, Aldeyra Therapeutics, Bausch & Lomb, Clearside Biomedical, Dompe pharmaceutical, Eyegate Pharma, Mallinckrodt pharmaceuticals, Novartis, pSivida and Santen. Payment for lectures including service on speaking bureaus from Alcon and Allergan. Stock or stock options in Eyegate Pharma. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This paper was not funded.