文字や絵視標で固視検査ができる検眼鏡の開発―フィルターの効果について

Prototype of ophthalmoscope with built-in optotypes and filters for examination of fixation

要約　目的：簡便に固視検査ができる検眼鏡の報告。対象と方法：文字と絵視標を内蔵した検眼鏡に，黄色，赤色，遮光用の3種のフィルターを組み込み，フィルターの有無による文字視認性と羞明の程度を，男性7名と女性5名が判定した。年齢は13～53歳で，網膜色素変性5名，錐体ジストロフィ5名，血管新生黄斑症1名，Leber視神経症1名を含み，7名に中心暗点，4名に求心性狭窄，1名に輪状暗点があった。結果：フィルターなしの状態では全例でまぶしさが強かった。黄色フィルター挿入ではまぶしさがあり，文字視認性が悪かった。赤色フィルター挿入で光量が減じ，視認性が向上した。遮光フィルター挿入で羞明がさらに減じ，視認性がよかった。結論：遮光フィルターを挿入した検眼鏡で，簡便に固視検査ができる見込みがある。

Abstract.　Purpose：To describe a modified ophthalmoscope to examine the status of fixation. Cases and Method：A commercially available ophthalmoscope with built-in optotypes were fitted with yellow, red and absorptive filters. Glare and readability of optotypes were judged by 12 patients with visual problems. Five had retinitis pigmentosa, 5 had cone dystrophy, one had choroidal neovascularization, and one had Leber optic neuropathy. Central scotoma was present in 7, concentric visual field in 4, and ring scotoma in one. Results：All the cases complained of glare when no filter was inserted. Use of yellow filter resulted in glare and poor recognition of optotypes. Use of red filter showed less glare and better recognition. Use of absorptive filter showed further reduction of glare and improved recognition. Conclusion：This modified ophthalmoscope promises to be of value in the examination of status of fixation.