ISO-ORIENTATION AREAS IN THE FOVEAL CONE MOSAIC
ISO-ORIENTATION AREAS IN THE FOVEAL CONE MOSAIC
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DOI：
10.1017/s0952523800000687
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发表时间：
1990-12-01
影响因子：
1.9
通讯作者：
GRASL, M
中科院分区：
文献类型：
--
作者：
PUM, D;AHNELT, PK;GRASL, M
人类和灵长类动物视网膜中央凹锥嵌合质量是空间视觉功能的一个基本参数。本研究使用数字纹理分析程序来分析包含中央凹锥体马赛克的无杆部分的内部片段的结晶顺序。通过充分的预处理，圆锥截面中心的定义可以精确映射晶格顶点，并通过直接邻居识别程序区分六边形位置。在进一步的步骤中，通过轴向的确定揭示了六边形区域内亚基的存在。亚基晶格具有取向相似和六边形单元位置相关性高的特点。这些区域的轴向与邻近亚单元的轴向不同，角位移为10-15度，边界由非六边形不规则的线性序列划定。虽然在周围无杆状体的区域出现了较大的连续六边形秩序斑块，但在中央凹中心（约300个锥体）发现了高度混乱（30%）。对显示标记B锥的马赛克的分析（Szel et al., 1988）表明，晶格紊乱部分与蓝色锥亚群有关。青光眼的中央凹镶嵌图显示整个无杆状体区的晶格严重退化，可能是由于广泛的受体丧失。低频上部结构导致具有不同取向偏差的采样网格局部集（5'-8'）。除了在水平/垂直方向上的马赛克压缩差异（约1:1.15）外，本分析没有提示在受体马赛克水平上存在系统的子向各向异性。该研究揭示了中央凹镶嵌的不连续组织，并指出了晶格紊乱的诱导和定位的可能来源。
The quality of the foveal cone mosaic in human and primate retinas is a basic parameter of spatial vision function. The present study uses digital-texture analysis procedures to analyze the crystalline order of inner segment sections containing the rod-free portions of foveal cone mosaics. Definition of the cone crosssectional centers made possible by adequate preprocessing allows precise mapping of lattice vertices and differentiation of hexagonal positions by procedures for direct neighbor recognition.In a further step, the existence of subunits within the hexagonal areas is revealed by the determination of axial orientation. The lattice of the subunits is characterized by similar orientation and high positional correlation of its hexagonal units.The axial orientation of the areas differs from that of neighboring subunits by angular shifts of 10-15 deg and linear series of nonhexagonal irregularities demarcate the borders. Although larger patches with continuous hexagonal order occur in the surrounding rod-free regions, elevated degrees of disorder (30%) are found within the foveolar center (ca. 300 cones). Analysis of a mosaic showing labeled B cones (Szel et al., 1988) demonstrates that lattice disorder is in part associated with the blue cone subpopulation. The foveal mosaic from a glaucomatuous eye reveals severe lattice degradation throughout the rod-free zone, presumably due to extensive receptor loss.The low-frequency superstructure results in local sets of sampling grids (5'-8') with differing orientational bias. Besides a horizontal/vertical difference of mosaic compression (ca. 1:1.15), the present analysis gives no hints for the existence of systematic meridional anisotropies at the receptor mosaic level. The study reveals a discontinuous organization of the foveal mosaic and points to possible sources for the induction and location of lattice disorder.