Wiecek Emily, Lashkari Kameran, Dakin Steven C, Bex Peter
Schepens Eye Research Institute/Mass. Eye and Ear, Boston, Massachusetts, United States.
Schepens Eye Research Institute/Mass. Eye and Ear, Boston, Massachusetts, United States Harvard Medical School, Department of Ophthalmology, Boston, Massachusetts, United States.
Invest Ophthalmol Vis Sci. 2014 Nov 18;56(1):494-504. doi: 10.1167/iovs.14-15394.
Patients with macular disease often report experiencing metamorphopsia (visual distortion). Although typically measured with Amsler charts, more quantitative assessments of perceived distortion are desirable to effectively monitor the presence, progression, and remediation of visual impairment.
Participants with binocular (n = 33) and monocular (n = 50) maculopathy across seven disease groups, and control participants (n = 10) with no identifiable retinal disease completed a modified Amsler grid assessment (presented on a computer screen with eye tracking to ensure fixation compliance) and two novel assessments to measure metamorphopsia in the central 5° of visual field. A total of 81% (67/83) of participants completed a hyperacuity task where they aligned eight dots in the shape of a square, and 64% (32/50) of participants with monocular distortion completed a spatial alignment task using dichoptic stimuli. Ten controls completed all tasks.
Horizontal and vertical distortion magnitudes were calculated for each of the three assessments. Distortion magnitudes were significantly higher in patients than controls in all assessments. There was no significant difference in magnitude of distortion across different macular diseases. There were no significant correlations between overall magnitude of distortion among any of the three measures and no significant correlations in localized measures of distortion.
Three alternative quantifications of monocular spatial distortion in the central visual field generated uncorrelated estimates of visual distortion. It is therefore unlikely that metamorphopsia is caused solely by retinal displacement, but instead involves additional top-down information, knowledge about the scene, and perhaps, cortical reorganization.
黄斑疾病患者常报告有视物变形（视觉扭曲）的经历。尽管通常使用阿姆斯勒表进行测量，但为了有效监测视力损害的存在、进展和恢复情况，需要对感知到的扭曲进行更定量的评估。
来自七个疾病组的双眼黄斑病变患者（n = 33）和单眼黄斑病变患者（n = 50），以及无明显视网膜疾病的对照参与者（n = 10）完成了一项改良的阿姆斯勒网格评估（在电脑屏幕上呈现并进行眼动追踪以确保注视依从性），以及两项用于测量中央5°视野视物变形的新评估。共有81%（67/83）的参与者完成了一项超敏锐度任务，即他们将八个点排列成正方形，64%（32/50）有单眼扭曲的参与者使用双眼分视刺激完成了一项空间对齐任务。十名对照者完成了所有任务。
对三项评估中的每一项都计算了水平和垂直扭曲程度。在所有评估中，患者的扭曲程度均显著高于对照者。不同黄斑疾病之间的扭曲程度没有显著差异。三项测量中的任何一项的总体扭曲程度之间均无显著相关性，局部扭曲测量也无显著相关性。
对中央视野单眼空间扭曲的三种替代量化方法得出了不相关的视觉扭曲估计值。因此，视物变形不太可能仅由视网膜移位引起，而是涉及额外的自上而下的信息、关于场景的知识，或许还涉及皮质重组。
