Heidelberg Retina Tomographおよび光干渉断層計による視神経乳頭形状測定の比較

Morphometry of optic nerve head by Heidelberg Retina Tomograph and optical coherence tomography

　Heidelberg Retina Tomograph（以下，HRT）および光干渉断層計（以下，OCT）を用い，健常眼での測定値，再現性に関して比較検討した。対象は健常者50名50眼で，年齢は19～42歳（25.1±4.6歳）。HRT，OCTの測定値は乳頭面積2.00±0.57mm²，2.44±0.43mm²，陥凹面積0.50±0.46mm²，0.60±0.43mm²，陥凹面積/乳頭面積比0.23±0.15，0.24±0.15，リム面積1.54±0.45mm²，1.91±0.43mm²，リム体積0.43±0.25mm³，0.68±0.53mm³であり，陥凹面積/乳頭面積比を除くパラメータでHRT測定値が有意に低値で，全パラメータで有意な相関があった。変動係数は，全パラメータでHRTのほうが有意に低値であったが，両者とも10％未満の良好な再現性を示した。

　Purpose：To compare optic nerve head measurements obtained by optical coherence tomography（OCT）and scanning laser tomography. Methods：We measured disc area,cup area,cup/disc area ratio,rim area,rim volume using OCT3000（Humphrey）and Heidelberg Retina Tomograph（HRT）in 50 eyes of 50 normal volunteers. Results：Mean disc area,cup area,cup/disc area ratio,rim area and rim volume was 2.00±0.57mm²,0.50±0.46mm²,0.23±0.15,1.54±0.45mm²and 0.43±0.25mm³with HRT and 2.44±0.43mm²,0.60±0.43mm²,0.24±0.15,1.91±0.43mm²and 0.68±0.53mm³with OCT. There were significant differences in the mean values of all parameter without cup/disc area ratio. A significant correlation coefficients was found in all parameters measured by both systems. The mean coefficients of variation（CV）of disc area,cup area,cup/disc area ratio,rim area,rim volume was 2.60％,5.15％,6.05％,4.75％,and 6.68％in HRT and 4.60％,9.25％,9.77％,6.14％,and 9.02％in HRT. Each system showed good reproducibility. A significant difference was found in the CVs of all parameters. Conclusions：The parameters measured by both systems showed good correlation coefficients. The HRT showed better reproducibility than the OCT. Both systems showed high reproducibility.