HLA-B27陽性で網膜色素変性症を伴った1例

Retinitis pigmentosa in a case positive for HLA-B27

　22歳女性が整形外科から紹介された。幼少時から夜盲があり，6歳時に視力低下を指摘され，以後弱視としてコンタクトレンズを装用していた。4年前より腎部から下肢にかけて疼痛があり，最近，整形外科で仙腸関節炎と診断された。HLA-B27陽性であり，これに伴う前部ぶどう膜炎の精査が紹介の理由であった。両眼に近視があり，矯正視力は右1.0，左0.8であった。前部ぶどう膜炎の所見はなく，両眼底に血管の狭細化と網膜色素上皮の粗糲化があった。求心性と輪状視野狭窄があり，網膜電図（ERG）は，scotopic, single flash, photopicともに減弱していた。以上から，網膜色素変性症と診断した。本症がHLA-B27陽性者に発症することは今まで報告されていない。

A 22-year-old woman was referred from the department of orthopedics. She had had night blind-ness since early childhood. She had been wearing contact lenses since the age of 6 years under the diagnosis of amblyopia. She had developed pain in the buttocks and lower extremities 4 years before. She had recently been diagnosed with sacroiliac arthritis. She was referred to us for possible anterior uveitis as she was also positive for HLA-B27. Her visual acuity was 1.0 right and 0.8 left when corrected for myopia. No signs of an-terior uveitis were present. Both fundus showed narrowing of retinal vessels and mottling of retinal pigment epithelium. Concentric and ring scotoma was present in both eyes. Electroretinogram (ERG) showed attenu-ated scotopic, single flash and photopic responses. These findings led to the diagnosis of retinitis pigmentosa. There has been no report of retinitis pigmentosa in persons positive for HLA-B27.