Ophthalmology Group, University of Leicester, Faculty of Medicine & Biological Sciences, Leicester Royal Infirmary, Leicester, United Kingdom.
Invest Ophthalmol Vis Sci. 2010 Jul;51(7):3502-8. doi: 10.1167/iovs.09-4236. Epub 2010 Mar 5.
PURPOSE. To investigate oculomotor strategies in strabismic amblyopia and evaluate abnormalities during monocular and binocular reading. METHODS. Eye movements were recorded with a head-mounted infrared video eye-tracker (250 Hz, <0.01 degrees resolution) in 20 strabismic amblyopes (mean age, 44.9 +/- 10.7 years) and 20 normal control subjects (mean age, 42.8 +/- 10.9 years) while they silently read paragraphs of text. Monocular reading comparisons were made between the amblyopic eye and the nondominant eye of control subjects and the nonamblyopic eye and the dominant eye of the control subjects. Binocular reading between the amblyopic and control subjects was also compared. RESULTS. Mean reading speed, number of progressive and regressive saccades per line, saccadic amplitude (of progressive saccades), and fixation duration were estimated. Inter- and intrasubject statistical comparisons were made. Reading speed was significantly slower in amblyopes than in control subjects during monocular reading with amblyopic (13.094 characters/s vs. 22.188 characters/s; P < 0.0001) and nonamblyopic eyes (16.241 characters/s vs. 22.349 characters/s, P < 0.0001), and binocularly (15.698 characters/s vs. 23.425 characters/s, P < 0.0001). In amblyopes, reading was significantly slower with the amblyopic eye than with the nonamblyopic eye in binocular viewing (P < 0.05). These differences were associated with significantly more regressive saccades and longer fixation durations, but not with changes in saccadic amplitudes. CONCLUSIONS. In strabismic amblyopia, reading is impaired, not only during monocular viewing with the amblyopic eye, but also with the nonamblyopic eye and binocularly, even though normal visual acuity pertains to the latter two conditions. The impaired reading performance is associated with differences in both the saccadic and fixational patterns, most likely as adaptation strategies to abnormal sensory experiences such as crowding and suppression.
目的。研究斜视性弱视的眼球运动策略，并评估单眼和双眼阅读时的异常情况。
方法。使用头戴式红外视频眼动追踪器（250 Hz，<0.01 度分辨率）记录 20 名斜视性弱视患者（平均年龄 44.9±10.7 岁）和 20 名正常对照者（平均年龄 42.8±10.9 岁）在安静阅读段落文本时的眼动。将弱视眼与对照组的非主导眼以及对照组的非弱视眼与主导眼进行单眼阅读比较。还比较了弱视眼和对照组之间的双眼阅读。
结果。估计平均阅读速度、每行的进展性和退行性扫视次数、扫视幅度（进展性扫视）和注视持续时间。进行了组内和组间的统计比较。
在单眼阅读时，弱视者的阅读速度明显慢于对照组，无论是弱视眼（13.094 个字符/s 比 22.188 个字符/s；P<0.0001）还是非弱视眼（16.241 个字符/s 比 22.349 个字符/s，P<0.0001），以及双眼阅读时（15.698 个字符/s 比 23.425 个字符/s，P<0.0001）。在斜视性弱视患者中，双眼阅读时，弱视眼的阅读速度明显慢于非弱视眼（P<0.05）。这些差异与退行性扫视次数增加和注视持续时间延长有关，但与扫视幅度变化无关。
结论。在斜视性弱视中，阅读受损，不仅在单眼使用弱视眼时，而且在使用非弱视眼和双眼时也会受损，尽管后两种情况的视力正常。受损的阅读表现与扫视和注视模式的差异有关，这很可能是对拥挤和抑制等异常感觉体验的适应策略。
