Waldock A, Potts M J, Sparrow J M, Karwatowski W S
Torbay Hospital, Torquay.
Br J Ophthalmol. 1998 Mar;82(3):260-6. doi: 10.1136/bjo.82.3.260.
To devise a method to describe and quantify the shape of polar profiles obtained with the scanning laser polarimeter and to compare this measurement with other polar profile measurements in a series of normal subjects and glaucoma patients.
Scanning laser polarimetry was performed on 54 normal subjects and 74 glaucoma patients. The retardation values obtained from one randomly chosen eye of each subject were analysed using our own methods, including the use of an algorithm to remove blood vessels from the polar profiles, an algorithm to standardise the glaucoma profiles to a normal database, and a further algorithm to evaluate the profile shape. The measurements of profile shape were compared with measurements of the absolute and standardised retinal nerve fibre layer thickness obtained with the scanning laser polarimeter.
There was no significant difference between the mean retardation values for the normal and glaucomatous subjects in either hemiretina. However, standardisation of the glaucoma retardation values to a normal database produced significant differences at p < 1 x 10-8 in the mean retardation values for these two groups in both hemiretinas. Profile shape measurement analysis produced similar significant differences between the mean retardation values for the normal and glaucomatous subjects in both hemiretinas, although the degree of separation was greater following standardisation of the retardation values.
The use of an algorithm to standardise an individual's retardation values in conjunction with a blood vessel removal algorithm enables an improvement in the ability of the scanning laser polarimeter to discriminate between normal and glaucomatous patients. The polar profile shape algorithm is independent of standardisation and significantly improves the discrimination between normal and glaucomatous patients, as well as providing additional information regarding the retinal nerve fibre layer.
设计一种方法来描述和量化用扫描激光偏振仪获得的偏振轮廓形状，并将该测量结果与一系列正常受试者和青光眼患者的其他偏振轮廓测量结果进行比较。
对54名正常受试者和74名青光眼患者进行扫描激光偏振测量。使用我们自己的方法分析从每个受试者一只随机选择的眼睛获得的延迟值，包括使用一种算法从偏振轮廓中去除血管，一种将青光眼轮廓标准化到正常数据库的算法，以及另一种评估轮廓形状的算法。将轮廓形状的测量结果与用扫描激光偏振仪获得的绝对和标准化视网膜神经纤维层厚度的测量结果进行比较。
在任一视网膜半侧，正常受试者和青光眼受试者的平均延迟值之间均无显著差异。然而，将青光眼延迟值标准化到正常数据库后，这两组在两个视网膜半侧的平均延迟值在p < 1 x 10-8时有显著差异。轮廓形状测量分析在两个视网膜半侧的正常受试者和青光眼受试者的平均延迟值之间也产生了类似的显著差异，尽管在延迟值标准化后分离程度更大。
使用一种算法将个体的延迟值标准化并结合血管去除算法能够提高扫描激光偏振仪区分正常和青光眼患者的能力。偏振轮廓形状算法独立于标准化，显著提高了正常和青光眼患者之间的区分能力，并提供了有关视网膜神经纤维层的额外信息。
