Université Aix-Marseille II, Institut de Neurosciences Cognitives de la Méditerranée, CNRS, Marseille, France.
Invest Ophthalmol Vis Sci. 2010 Feb;51(2):1247-54. doi: 10.1167/iovs.09-3682. Epub 2009 Oct 15.
It has been suggested that crowding, the adverse low-level effect due to the proximity of adjacent stimuli, explains slow reading in low-vision patients with absolute macular scotomas. According to this hypothesis, crowding in the vertical dimension should be released by increasing the vertical spacing between lines of text. However, studies with different experimental paradigms and only a few observers have given discrepant results on this question. The purpose of this study was to investigate this issue with a large number of patients whose macular function was carefully assessed.
MP1 microperimetry examination was performed for each low-vision patient. Only eyes with an absolute macular scotoma and no foveal sparing (61 patients with AMD, 90 eyes; four patients with Stargardt disease, eight eyes) were included. Maximal reading speed was assessed for each eye with French sentences designed on the MNREAD test principles.
The effect of interline spacing on maximal reading speed (MRS) was significant although small; average MRS increased by 7.1 words/min from standard to double interline spacing. The effect was weak irrespective of PRL distance from the fovea and scotoma area and regardless of whether an eccentric island of functional vision was present within the scotoma.
Increasing interline spacing is advisable only for very slow readers (<20 words/min) who want to read a few words (spot reading). Vertical crowding does not seem to be a major determinant of maximal reading speed for patients with central scotomas.
有人认为拥挤是由于相邻刺激物的接近而产生的不利低水平效应，这可以解释绝对黄斑暗点的低视力患者阅读速度缓慢的原因。根据这一假设，通过增加文本行之间的垂直间距，可以释放垂直方向上的拥挤。然而，具有不同实验范式和仅少数观察者的研究对这一问题给出了不一致的结果。本研究的目的是用大量仔细评估黄斑功能的患者来研究这个问题。
对每个低视力患者进行 MP1 微视野检查。仅包括具有绝对黄斑暗点且无黄斑中心凹保留的眼（61 例 AMD 患者，90 只眼；4 例 Stargardt 病患者，8 只眼）。使用基于 MNREAD 测试原理设计的法国句子评估每只眼的最大阅读速度。
尽管间隔大小对最大阅读速度（MRS）的影响较小，但增加行间距可使 MRS 平均提高 7.1 个单词/分钟，从标准行间距到双倍行间距。该效果与 PRL 距黄斑中心凹和暗点区域的距离以及暗点内是否存在功能视觉的偏心岛无关，均较弱。
对于想要阅读少量单词（点读）的非常缓慢的阅读者（<20 个单词/分钟），增加行间距是可取的。垂直拥挤似乎不是中心暗点患者最大阅读速度的主要决定因素。
