Pointer Jonathan S
Optometric Research, 4A Market Square, Higham Ferrers, Northants NN10 8BP, UK.
Ophthalmic Physiol Opt. 2008 Sep;28(5):457-66. doi: 10.1111/j.1475-1313.2008.00584.x.
The maintenance of a good level of vision is desirable for developmental and social reasons; it is also a requirement that should not be overlooked in the clinical research environment. This study set out to quantify and analyse any difference between 'habitual' (pre-sight test) and 'optimal' (post-refraction) distance visual acuity in an optometric population. It is intended that the outcome of this work will inform not only clinicians but also those undertaking vision research.
Binocular logMAR visual acuity was determined at 6 m before and after optometric intervention in patients attending optometric practice for a routine sight test. Cases were recorded seriatim but restricted to the 'core' refraction range representative of typical optometric practice; three further exemption criteria included subject illiteracy, the necessity for a non-standard test distance and contact lens wear. Over a 12-month period, two-thirds of patients examined satisfied the study inclusion criteria; it is the clinical data of these 1288 individuals that are described and analysed here.
These data provide a quantitative demonstration that an optometric intervention will most likely improve the habitual distance visual acuity of subjects, irrespective of gender, age group, time interval since last test, refractive status and whether or not the subject is a habitual spectacle wearer. The improvement found was typically within one logMAR chart line (<5 letters), being greatest in spectacle-wearing teenagers and in individuals beyond retirement age (increasing to eight letters in elderly habitual non-spectacle wearers); also in non-wearers who left an interval of 2 years or more between sight tests.
Clinical and laboratory-based investigators are advised that a current and optimal refractive correction should be worn by subjects of all ages enrolled in vision-related studies. Refractive defocus may introduce or exaggerate test outcome variability.
出于发育和社会原因，保持良好的视力水平是很有必要的；这也是临床研究环境中不应被忽视的一项要求。本研究旨在量化和分析验光人群中“习惯”（视力测试前）和“最佳”（验光后）远视力之间的差异。这项工作的结果不仅旨在为临床医生提供信息，也为从事视力研究的人员提供信息。
对前来验光诊所进行常规视力检查的患者，在验光干预前后分别于6米处测定双眼对数最小分辨角视力（logMAR）。病例按顺序记录，但仅限于代表典型验光实践的“核心”验光范围；另外三个排除标准包括受试者文盲、非标准测试距离的必要性以及佩戴隐形眼镜。在12个月的时间里，接受检查的患者中有三分之二符合研究纳入标准；这里描述和分析的是这1288名个体的临床数据。
这些数据提供了定量证明，即验光干预很可能会提高受试者的习惯远视力，无论性别、年龄组、自上次测试以来的时间间隔、屈光状态以及受试者是否为习惯性眼镜佩戴者。发现的改善通常在一个logMAR视力表行内（<5个字母），在佩戴眼镜的青少年和退休年龄以上的个体中最大（老年习惯性不戴眼镜者增加到8个字母）；在两次视力测试间隔2年或更长时间的不戴眼镜者中也是如此。
建议临床和实验室研究人员，参与视力相关研究的所有年龄段受试者都应佩戴当前的最佳屈光矫正。屈光性散焦可能会引入或夸大测试结果的变异性。
