夜盲症状を有する若年症例に対する暗所視支援眼鏡を用いた歩行調査

A walking survey for young patients with nyctalopia using eyeglasses for night vision support

要約　目的：暗所視支援眼鏡HOYA MW10 HiKARI（MW10）を用いて夜盲症状を有する若年症例に対して歩行調査を行い，MW10の有効性と問題点を検討した。

対象と方法：夜盲症状を有する若年社会人5例（男性2例：女性3例，年齢38.0±7.0歳）を対象とした。MW10非装用時と装用時で，暗所（1〜2ルクス程度）の室内を決められたルートに従って歩行する調査を行い，遂行の可否と所要時間を検討した。対照として健常人5例（男性1例：女性4例，年齢37.8±10.4歳）に同様の調査を行い，比較した。夜盲症例にはMW10の見え方や装用感のアンケート調査を実施した。

結果：夜盲症例はMW10非装用では1例のみが，装用では5例全員が歩行調査を遂行できた。健常人は5例全員が非装用時，装用時ともに歩行調査を遂行できた。所要時間に関しては，夜盲症例では非装用時に遂行できた1例は，装用時（39秒）は非装用時（105秒）に比べ大幅に短縮した。装用時の所要時間は夜盲症例104±78秒で，健常人24±5秒に比べて有意に長かった（p＜0.01）。アンケートでは，全員からMW10は見え方の補助になると思うが，装用感として重い，大きいなどの感想が挙がった。

結論：MW10は夜盲症状を有する若年症例に対して暗所での見え方や歩行に役立つ可能性があるが，携帯性やデザイン性の改善が求められる。

Abstract　Purpose：To investigate the efficacy and limitations of HOYA MW10 HiKARI^®（MW10）, eyeglasses for night vision support, in young patients with nyctalopia through a walking survey.

Subjects and methods：Five young adult patients（two men and three women；the mean age, 38.0±7.0 years）with symptoms of nyctalopia were included in this study. In the survey, the patients walked a predetermined route in a dark room（approximately 1-2 lux）. The two patterns, with and without MW10, were investigated in each participant. The pros and cons of execution and the time required were also assessed. As a control, five healthy people（one man and four women；the mean age, 37.8±10.4 years）participated in the walking survey, and both groups were compared. A questionnaire was administered to the patients with nyctalopia to understand how they see and feel wearing MW10.

Results：In the patient's group, only one patient reached the goal without wearing MW10, and all five patients reached the goal with MW10. All five controls could reach the goal with and without MW10. The time required for the patient, who was able to reach the goal shortened after wearing MW10（105 to 39 seconds）. In the wearing pattern, the time required for patients was significantly longer than that in the healthy subjects（104±78 seconds and 24±5 seconds, respectively；p＜0.01）. In the questionnaire, all patients answered that MW10 would help their vision but that wearing it felt heavy and big.

Conclusions：MW10 has the potential to help young patients with nyctalopia to see and walk in the dark. However, its portability and design need to be improved.