Birdshot chorioretinopathy is a rare, chronic, autoimmune uveitis with unknown pathophysiology and significant diagnostic and therapeutic challenges. While previous treatment strategies mainly relied on conventional immunosuppressive agents, there are increasing number of patients refractory to conventional therapy cured with the administration of adalimumab worldwide [1]. Herein, we report a South Korean patient with birdshot chorioretinopathy successfully treated with adalimumab. This study was approved by the Institutional Review Board of Seoul National University Bundang Hospital (No. B-2410-929-701). Written informed consent for publication of the research details and clinical images was obtained from the patient.

A 40-year-old female patient with posterior uveitis of the left eye was referred to our clinic complaining of decreased visual acuity in the same eye. She had previously been treated with oral prednisolone of unspecified dosage at primary ophthalmic clinic. Best-corrected visual acuity of the left eye was 20 / 22. Slit-lamp examination showed 1+ grade of cells in the anterior vitreous and multiple orange- colored lesions were found on fundus examination. (Fig. 1A-1H) Under the assessment of birdshot chorioretinopathy, oral prednisolone of 40 mg (0.67 mg/kg) per day and mycophenolate mofetil of 1,000 mg per day were prescribed. Three weeks after treatment, moderate leakage on fluorescein angiography and hyper-autofluorescence in the peripheral retina on fundus autofluorescence were found with grade 1+ of cells in the anterior vitreous of the right eye on slit lamp examination. However, 11 weeks after treatment, the patient complained of blurry vision and ocular pain. Corrected visual acuity of the left eye was 20 / 200 and slit-lamp examination showed grade 2+ of cells in both the anterior chamber and anterior vitreous in both eyes. Due to aggravation of intraocular inflammation, oral prednisolone of 40 mg per day was prescribed again and adalimumab injection of 40 mg every 2 weeks was started with an initial dose of 80 mg. Three weeks after initiation of adalimumab, blurred vision was relieved, and slit-lamp examination showed decreased cells in the anterior chamber of the right eye and grade 1+ of cells in the anterior vitreous of both eyes. Adalimumab was continued while controlling the dose of mycophenolate mofetil depending on the changes of intraocular inflammation. Six months after initiation of adalimumab, no leakage of retinal vessels was found on fluorescein angiography, and no further evidence of active inflammation was detected. On her last visit, 2 years after the initiation of adalimumab treatment, best-corrected visual acuity of the left eye was 20 / 30. Slitlamp examination showed no cells in the anterior chamber and anterior vitreous of both eyes and fundus examination revealed decreased multiple orange-colored lesions of both eyes. We recommended maintenance of adalimumab treatment with 4 weeks of interval.

To manage birdshot chorioretinopathy, immunosuppressive medications like systemic corticosteroids and immunomodulators are used to control inflammation and preserve vision [2]. Early detection can enhance prognosis, but some cases may experience worsening vision [3]. Consistent follow-ups are vital for effective treatment and disease management, sometimes requiring new medications. Recent studies highlight the potential of adalimumab in treating ocular inflammations, especially in cases unresponsive to standard therapies of steroid and other immunomodulatory agents [4]. To confirm the diagnosis of birdshot chorioretinopathy, HLA-A29 genotyping should be introduced, particularly considering the diagnostic challenges posed by its rarity in Asian populations.

In conclusion, adalimumab, a potent anti-inflammatory medication, has the potential for successful treatment of refractory birdshot chorioretinopathy. Due to its unclarified pathogenesis and difficulties of diagnosis, birdshot chorioretinopathy poses challenges to its treatment. Although conventional immunomodulatory agents like systemic corticosteroid and mycophenolate mofetil have succeeded in many birdshot chorioretinopathy cases, patients refractory to these treatments remain. Our case suggests that adalimumab can be considered an effective treatment for patients with refractory birdshot chorioretinopathy. Further studies including a large number of cases are needed to assess the efficacy and safety of long-term use of adalimumab in patients with birdshot chorioretinopathy.