Stargardt病患者の黄斑部機能評価

Macular function in a case of Stargardt's disease

　65歳の女性が飛蚊症で受診した。矯正視力は両眼とも1.0で，昼盲・夜盲はなく，特記すべき家族歴はなかった。両眼とも，特徴的な眼底所見と蛍光眼底造影所見を呈し，Stargardt病・黄色斑眼底IV群と診断した。以後8年間，黄色斑の数と範囲はやや増加し，視力は不変である。ゴールドマン視野検査では異常がなく，走査レーザー検眼鏡（SLO）での微小視野計測で，固視点周囲に比較暗点が検出された。EOGでは，Arden比がやや低下していた。Full fieldの網膜電図はほぼ正常であった。多局所網膜電図（mERG）では，中心から10度付近に輪状の応答密度の低下があった。これらの検査法が本症での視機能評価に有用であることを示す症例である。

A 65-year-old female presented with seeing flies. Her corrected visual acuity was 1.0 in either eye. She had neither day nor night blindness. Family history was inconspicuous. Both eyes showed characteristic fundus and fluorescein angiographic findings of Stargardt disease/fundus flavimaculatus group IV . The yellow flecks in the fundus slightly increased in number and involved area during the follow-up of 8 years. The visual acuity has remained unchanged. Goldmann perimetry showed no abnormalities. Microperimetry using a scanning laser ophthalmoscope (SLO) showed a ring-shaped relative scotoma around the point of fixation. Electro - oculography showed a slightly decreased L/D ratio. Full-field electroretinography (ERG) showed normal responses. Multifocal ERG showed a ring-shaped zone of decreased response 10 degrees away from the center. This case illustrates the usefulness of above methods of examination in evaluating the visual function in Stargardt disease.