Wills Jocelyn, Gillett Robyn, Eastwell Emmeline, Abraham Rachel, Coffey Kristin, Webber Ann, Wood Joanne
School of Optometry and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
Optom Vis Sci. 2012 Mar;89(3):271-6. doi: 10.1097/OPX.0b013e3182429c6b.
Few studies have specifically investigated the functional effects of uncorrected astigmatism on measures of reading fluency. This information is important to provide evidence for the development of clinical guidelines for the correction of astigmatism.
Participants included 30 visually normal, young adults (mean age, 21.7 ± 3.4 years). Distance and near visual acuity and reading fluency were assessed with optimal spectacle correction (baseline) and for two levels of astigmatism, 1.00 diopter cylinder (DC) and 2.00 DC, at two axes (90 and 180°) to induce both against-the-rule (ATR) and with-the-rule (WTR) astigmatism. Reading and eye movement fluency were assessed using standardized clinical measures including the test of Discrete Reading Rate (DRR), the Developmental Eye Movement test (DEM), and by recording eye movement patterns with the Visagraph (III) during reading for comprehension.
Both distance and near acuity were significantly decreased compared with baseline for all the astigmatic lens conditions (p < 0.001). Reading speed with the DRR for N16 print size was significantly reduced for the 2.00 DC ATR condition (a reduction of 10%), whereas for smaller text sizes, reading speed was reduced by up to 24% for the 1.00 DC ATR and 2.00 DC condition in both axis directions (p < 0.05). For the DEM, subtest completion speeds were significantly impaired, with the 2.00 DC condition affecting both vertical and horizontal times and the 1.00 DC ATR condition affecting only horizontal times (p < 0.05). Visagraph reading eye movements were not significantly affected by the induced astigmatism.
Induced astigmatism impaired performance on selected tests of reading fluency, with ATR astigmatism having significantly greater effects on performance than did WTR, even for relatively small amounts of astigmatic blur of 1.00 DC. These findings have implications for the minimal prescribing criteria for astigmatic refractive errors.
很少有研究专门调查未矫正散光对阅读流畅性测量的功能影响。这些信息对于为散光矫正临床指南的制定提供证据很重要。
参与者包括30名视力正常的年轻成年人（平均年龄21.7±3.4岁）。使用最佳眼镜矫正（基线）以及在两个轴（90°和180°）上的两个散光度数水平，即1.00屈光度柱镜（DC）和2.00 DC，来评估远视力和近视力以及阅读流畅性，以诱导逆规（ATR）和顺规（WTR）散光。使用标准化临床测量方法评估阅读和眼动流畅性，包括离散阅读速度测试（DRR）、发育性眼动测试（DEM），并在阅读以理解内容时使用Visagraph（III）记录眼动模式。
与基线相比，所有散光镜片条件下的远视力和近视力均显著下降（p < 0.001）。对于2.00 DC ATR条件，N16字体大小的DRR阅读速度显著降低（降低10%），而对于较小字体大小，在两个轴向上，1.00 DC ATR和2.00 DC条件下的阅读速度降低高达24%（p < 0.05）。对于DEM，子测试完成速度显著受损，2.00 DC条件影响垂直和水平时间，1.00 DC ATR条件仅影响水平时间（p < 0.05）。Visagraph阅读眼动未受到诱导散光的显著影响。
诱导散光会损害所选阅读流畅性测试的表现，即使对于1.00 DC相对较小的散光模糊量，ATR散光对表现的影响也明显大于WTR。这些发现对散光屈光不正的最小处方标准具有启示意义。
