[Birdshot chorioretinopathy--a case report and a case study in Japanese patients]

There have been numerous case reports of birdshot chorioretinopathy(BC) from Europe and USA. However, only 10 cases of BC have been reported in Japan. We report the case of a Japanese patient with BC and review the clinical characteristics of BC among Japanese patients previously reported.

We report the case of a 64-year-old Japanese man, who was seen at our clinic and then diagnosed as hasing BC. 20 eyes of 11 patients with BC reported in the Japanese literature previously, including our patient, were studied. Age at the initial onset, sex, ocular findings, prognosis of visual acuity and the human leucocyte antigen (HLA) were evaluated.

In our case bilateral cream-colored subretinal exudates presented symmetrically and in time developed depigmented atrophic 'birdshot like' scar lesions. Ocular inflammation responded to oral prednisolone without exacerbation and good visual acuity was maintained. The age at the onset ranged from 19 to 78 years(mean 54.5), and 8 patients were women. Cystoid macular edema(CME) was found in 30% of 11 Japanese patients, and optic disc edema was seen in 50%. Final visual acuity was more than 20/40 in 75% and less than 20/200 in 12.5% of the cases. HLA-A 29, which is frequently associated with Caucasian patients, was not positive in any of the Japanese patients, and no specific locus was determined.

We observed a rare case of BC. Age at initial onset, sex, and ocular findings of Japanese patients with BC were consistent with those of Europe and the US and good visual acuity was maintained in almost all cases. We suggest that the disease mechanism of BC in Japanese patients is different from that of Caucasian patients, because HLA-A 29 was negative in all Japanease patients.