To evaluate the peripapillary distribution of retinal nerve fiber layer thickness (RNFLT) in normal eyes using spectral-domain optical coherence tomography and to study potentially related factors. Methods: In 7 institutes in Japan, RNFLT in 7 concentric peripapillary circles with diameters ranging from 2.2 to 4.0 mm were measured using spectral-domain optical coherence tomography in 251 ophthalmologically normal subjects. Multiple regression analysis for the association of RNFLT with sex, age, axial length, and disc area was performed. Results: Retinal nerve fiber layer thickness decreased linearly from 125 to 89 µm as the measurement diameter increased (PϽ.001, mixed linear model). Retinal nerve fiber layer thickness correlated with age in all diameters (partial correlation coefficient [PCC] = −0.40 to −0.32; PϽ .001) and negatively correlated with disc area in the 2 innermost circles but positively correlated in the 3 outermost circles (PCC=−0.30 to −0.22 and 0.17 to 0.20; P Յ .005). Sex and axial length did not correlate with RNFLT (PϾ.08). The decay slope was smallest in the temporal and largest in the nasal and inferior quadrants (PϽ.001); positively correlated with disc area (PCC=0.13 to 0.51; PՅ .04); and negatively correlated with RNFLT (PCC=−0.51 to −0.15; P Յ.01). Conclusions: In normal Japanese eyes, RNFLT significantly correlated with age and disc area, but not with sex or axial length. Retinal nerve fiber layer thickness decreased linearly as the measurement diameter increased. The decay slope of RNFLT was steepest in the nasal and inferior quadrants and steeper in eyes with increased RNFLT or smaller optic discs.

PPA bed configurations detected by SD-OCT were classified into three types. The lack of BM on the PPA bed was closely associated with myopia. The downward-curved appearance of BM may be related to the anatomic changes associated with glaucoma.

The cross-sectional anatomic configurations of the peripapillary atrophy were evaluated by using SD-OCT. The termination of the retinal layers and configurations of the scleral bed in the peripapillary area varied among normal subjects.

Ferromagnetism and accompanying large negative magnetoresistance in Pb-substituted Bi-Sr-Co-O misfit-layer compound are investigated in detail. Recent structural analysis of (Bi,Pb)2Sr3Co2O9, which has been believed to be a Co analogue of Bi2Sr2CaCu2O 8+δ , revealed that it has a more complex structure including a CoO2 hexagonal layer [T. Yamamoto et al., Jpn. J. Appl. Phys. 39 (2000) L747]. Pb substitution for Bi not only introduces holes into the conducting CoO2 layers but also creates a certain amount of localized spins. Ferromagnetic transition appears at T = 3.2 K with small spontaneous magnetization along the c axis, and around the transition temperature large and anisotropic negative magnetoresistance was observed. This compound is the first example which shows ferromagnetic long-range order in a two-dimensional metallic hexagnonal CoO2 layer.

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