変視症の定量化に関する研究—測定方法について

Quantitation of metamorphopsia. Method of evaluation

　種々の網膜疾患において小視症，大視症を含め変視症を訴える症例は非常に多い。今回我々は変視症の定量化の新しい試みとしてパーソナルコンピューターを用いたCRT上での測定方法を検討した。同一眼において，黄斑部に配置した2度間隔の計48点の各測定点に順次呈示される視角1度の視標と，基準となる固視点の視標を比較し大きさを合わせることにより変視量を定量的に算出した。正常者や種々の網膜疾患に応用した結果，浮腫の部位では小視症が，また陳旧性，瘢痕性病変では大視症が測定され，これらの所見は自覚症状とも一致した。今回の方法は，変視症の定量的測定法として有用であると考えられた。

We developed a new method to quantitate metamorphopsia with the use of personal computer and cathode-ray tube (CRT). A series of 48 targets were consecutively presented on the CRT within the field of 6 degrees from the fixating point. Each target was compared with the reference target presented at the point of fixation. The examine was asked to change the size of the target until the twotargets were recognized as equal in size. The ratio of projected versus fixed target was defined to express the value for metamorphopsia, or microp-sia ratio.

We applied this method to 30 normal eyes and to eyes with macular lesions. The observed values in pathologic eyes tended to micropsia when the affected retinal area was edematous. The tended to macropsia where the retina was cicatricial. Our present method seemed to be of value for quantita-tive mapping of metamorphopsia.