標準色覚検査表第1部の表の類別と各表の検査能力

Grouping and abilities of individual plates in "Standard Pseudoisochromatic Plates Part 1"

　標準色覚検査表第1部先天異常用（SPP-1）の個々の表を評価する際の便のために，表を構成する色が同じであるものをまとめて，6群に類別する．1群から4群までが検出表，5群と6群は分類表である．

　先天性赤緑色覚異常者431例を対象としてSPP-1の検出，分類能力と，個々の表の特徴を検討した．検出は二色型色覚100％，異常三色型色覚95.8％，全体で97.7％可能であった．分類は二色型色覚は全例，異常三色型色覚は97.3％，全体で98.4％が正しく分類された．

　各表ごとにみると，検出表では，検出力の優劣がひとつの群に共通であるとは限らない．4群は2表とも検出力がよいが，1群は非常に検出のよいものと非常に悪いものがある．分類表では5群は極めて高い分類能力を示すが，6群は分類不明となるものが特に第二異常に多い．

　検出にしても分類にしても，個人差をカバーするためには種類の違う表を併用する必要がある．それにより，一表ずつの検査能力は必ずしもよくなくても全体として優れた成績を得ることができる．

"The Standard Pseudoisochromatic Plates Part 1 (SPP-1)" is comprised of 10 screening and 5 clas-sification plates. These 15 plates were divided into 6 groups according to the colors composing each plate.

Group 1, or GY plates, are of green background (2.5GY and 7.5GY Munsell). Plates 5, 10 and 12 belong to this group. Group 2, or B Plates, are of blue background (5B Munsell). Plates 6, 8 and 14 belong to this group. Group 3, or YR plates, are of brown background (7.5YR Munsell) Plates 7 and 13 belong to this group. Group 4, or Pplates, are of purple background (5P Munsell). Plates 9 and 11 belong to this group. Group 5, or PR plates, are of red-purple background (2.5 RP Munsell). Plates 15, 17 and 19 belong to this group. Group 6, or N plates, are of grey background. Plates 16 and 18 belong to this group.

We examined 431 cases with congenital red-green defect using SPP-1. Using the 10 screening plates, 97.7% of the cases were diagnosed to be color defective. Using the 5 classification plates, 98.4% were correctly classified.

Plates from a same group in the screening series did not always give similar scores. No satisfactory explanation has been found for this phenomenon.

Plates belonging to group 5 in the classification series gave the best results in classifying the cases into protan or deutan. Plates of group 6 gave significantly poorer results in classification. There were occasionally cases with mild color defects, though, who were classified by plates of group 6 exclusively. It appeared that plates in different groups were interdependent and produced good results when used as a whole. The same seemed to apply to plates of the screening series.