Frisén Lars
Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Acta Ophthalmol. 2014 Dec;92(8):805-9. doi: 10.1111/aos.12405. Epub 2014 Apr 3.
Diagnosis of functional visual field loss, that is, field loss lacking objective corollaries, has long relied on kinetic visual field examinations using tangent screens or manual perimeters. The modern dominance of automated static perimeters requires the formulation of new diagnostic criteria.
Retrospective review of automated perimetry records from 36 subjects meeting clinical and tangent screen criteria for functional visual field loss. Thirty-three normal eyes and 57 eyes with true lesions, including optic nerve compression, glaucoma, anterior ischaemic optic neuropathy and vigabatrin toxicity, served as controls.
Standard automated perimetry statistics were unable to reliably discriminate organic versus non-organic visual field loss. Subjective evaluation of perimetric maps indicated that functional fields generally could be identified by the presence of severe and irregular contractions and depressions that did not conform to the visual system's neuro-architecture. Further, functional fields generally presented one or more isolated threshold 'spikes', that is, isolated locations showing much better than average sensitivity. On repeated examinations, threshold spikes always changed locations. Visual evaluation for spikes proved superior to an objective computational algorithm. Fairly reliable objective discrimination of functional fields could be achieved by point-wise correlations of repeated examinations: median intertest correlation coefficients equalled 0.47 compared with 0.81 for true lesions.
Functional visual loss can be identified by automated static perimetry. Useful criteria include severe and irregular contractions and depressions, the presence of isolated threshold spikes and poor intertest correlations.
功能性视野缺损，即缺乏客观相应表现的视野缺损，长期以来一直依靠使用切线屏或手动视野计进行的动态视野检查来诊断。自动静态视野计的现代主导地位要求制定新的诊断标准。
回顾性分析36例符合功能性视野缺损临床及切线屏标准的受试者的自动视野检查记录。33只正常眼和57只患有真性病变的眼睛，包括视神经受压、青光眼、前部缺血性视神经病变和氨己烯酸毒性反应，作为对照。
标准自动视野检查统计数据无法可靠地区分器质性与非器质性视野缺损。对视野图的主观评估表明，功能性视野通常可通过存在严重且不规则的收缩和凹陷来识别，这些收缩和凹陷不符合视觉系统的神经结构。此外，功能性视野通常呈现一个或多个孤立的阈值“尖峰”，即孤立的位置显示出远高于平均水平的敏感度。在重复检查时，阈值尖峰总是改变位置。对尖峰的视觉评估证明优于客观计算算法。通过重复检查的逐点相关性可以实现对功能性视野的相当可靠的客观区分：测试间中位数相关系数为0.47，而真性病变为0.81。
功能性视力丧失可通过自动静态视野计识别。有用的标准包括严重且不规则的收缩和凹陷、孤立阈值尖峰的存在以及测试间相关性差。
