Rolando M, Macri A, Altieri M, Iester M
Department of Ophthalmology, University of Genoa, Italy.
Int Ophthalmol. 1996;20(1-3):15-20. doi: 10.1007/BF00212939.
Since the glaucomatous loss of nerve fibers changes the appearance of the optic disc, we evaluated the morphology of the surface of the optic disc in normal and glaucomatous eyes by using a computerized system to provide the reciprocal position of a large number of points placed on its surface in order to study the clinical significance of differences in the 'smoothness' of optic disc surface.
The morphology of the optic disc surface was evaluated by means of simultaneous stereoscopic videographic pictures (IMAGEnet X Rev-3.51b-Topcon Europe, The Netherlands): the reciprocal distribution of a large number of points located on the surface of one eye of 100 subjects randomly chosen (45 normal and 55 glaucoma patients) was studied. In order to define the level of 'smoothness' of the optic disc surface, the differences of the relative position of each surface point were studied by measuring the standard deviation (SD) from the average heights of the points (n. ranging from 623 to 1916 depending on the size of the disc area) that identify the optic disc surface.
The coefficient of variation of the reciprocal location of the points, placed on the optic disc surface at the different measurements performed by a single operator was 10.4%. The differences in Optic Disc Surface Smoothness (ODSS) between glaucoma and normal group were statistically significant (p < 0.0001 using Mann-Whitney U test). No correlation was detectable between age and standard deviation. The best threshold value, calculated using ROC methodology, able to separate the two groups was: normal group: SD < or = 17.79 (-1 x 10(-2) mm); glaucoma group: SD > -17.79 (-1 x 10(-2) mm). Such threshold value had a sensitivity of 82.1%, a specificity of 92.2% and a diagnostic precision (DP) of 86.5% in dividing the glaucoma group from the normal group.
ODSS is a global index of optic disc conditions based on quantitative measurements of the morphology of the optic disc surface. As such it does not provide information about the location and the characteristics of optic disc damage. Nevertheless, ODSS measurement is able to separate normal from glaucomatous optic disc with a rather interesting sensitivity, specificity and diagnostic precision (DP). As such it could be useful both for research and clinical applications.
由于青光眼导致的神经纤维缺失会改变视盘外观，我们使用计算机系统评估正常眼和青光眼眼中视盘表面的形态，以确定视盘表面大量点的相对位置，从而研究视盘表面“平滑度”差异的临床意义。
通过同步立体视频图像（IMAGEnet X Rev-3.51b-Topcon Europe，荷兰）评估视盘表面形态：研究随机选取的100名受试者（45名正常人和55名青光眼患者）一只眼睛视盘表面大量点的相对分布。为了确定视盘表面的“平滑度”水平，通过测量确定视盘表面的各表面点相对于平均高度的标准差（SD）（根据视盘区域大小，点数范围为623至1916），研究各表面点相对位置的差异。
由单个操作者在不同测量中放置在视盘表面的点的相对位置的变异系数为10.4%。青光眼组和正常组之间的视盘表面平滑度（ODSS）差异具有统计学意义（使用Mann-Whitney U检验，p < 0.0001）。年龄与标准差之间未检测到相关性。使用ROC方法计算得出的能够区分两组的最佳阈值为：正常组：SD ≤ 17.79（-1×10⁻²mm）；青光眼组：SD > -17.79（-1×10⁻²mm）。该阈值在区分青光眼组和正常组时的灵敏度为82.1%，特异性为92.2%，诊断精度（DP）为86.5%。
ODSS是基于对视盘表面形态进行定量测量的视盘状况的整体指标。因此，它不提供视盘损伤的位置和特征信息。然而，ODSS测量能够以相当可观的灵敏度、特异性和诊断精度（DP）区分正常视盘和青光眼视盘。因此，它在研究和临床应用中可能都很有用。
