アイトラッカーを用いた先天性眼振の強度測定

Intensity of congenital nystagmus measured by eye-tracking system

要約　目的：視線追跡装置であるアイトラッカーを用いて，先天性眼振の強度と波形を検索した報告。対象と方法：外来に通院中の先天性眼振4症例を対象とした。男児3名，女児1名で，3例が乳児眼振，1例が先天周期性交代性眼振であった。年齢はそれぞれ4，5，6，17歳であった。矯正視力は全例が0.6以上，2例が1.0以上であった。装置の中に指標を9方向に提示し，3～6秒ずつ注視させ，他覚的に眼振の強度と波形を解析した。結果：全例で眼振の強度と波形が解析できた。結論：アイトラッカーは先天性眼振の眼球運動の記録に有用であり，診断と治療の補助として使える可能性がある。

Abstract.　Purpose：To report attempts to evaluate the intensity and wave form of congenital nystagmus using an eye-tracking system. Cases and Method：This study was made on 4 cases with congenital nystagmus. The series comprised 3 males and 1 female. Three were diagnosed with infantile nystagmus and one with periodic alternating nystagmus. They were aged 4, 5, 6 and 17 years respectively. Corrected visual acuity was 0.6 or over in all the cases and was 1.0 or over in 2 cases. They were instructed to fixate targets for 3 to 6 seconds that were displayed in the instrument in either of 9 directions. Intensity and wave form of nystagmus were recorded and analyzed. Results：It was possible to record the intensity and wave form of nystagmus in all the patients. Conclusion：It is possible to record and analyze the intensity and wave form of congenital nystagmus using the eye-tracking system. This system promises to be useful as adjunct to diagnosis and treatment of nystagmus in children.