Measuring accommodative facility

在附近评估住宿功能是理解患者的近视概况的重要组成部分。儿童和成人的近视进展可能受双目视觉功能的影响。与Emmetropes相比，据报道，近视儿童和年轻成年人的近期近期的食电镜和住宿滞后之间的关联。^1-5Myopic children and young adults also show insufficient accommodative responses to lens-induced blur,^1,6-8greater variability in accommodative response⁹，减少宽敞的容纳设施^{4, 8}与年龄匹配的Emmetropes相比，增强了增强的容纳收敛（升高的AC /比率）。^10-12There is speculation in the literature regarding accommodative lag prior to onset of myopia – evidence shows higher accommodative lag in progressing myopes, regardless of their starting point of refraction as an emmetrope or myope,⁴however other studies do not match this significance.¹³Myopia development and progression is multifactorial, though, so it’s important to assess all contributory factors – the myopia profile is designed to guide you through this clinical decision making and communication process.

A recent study from China has shown that children with a lower amplitude of accommodation showed a better myopia control response to orthokeratology over two years, indicating that improving accommodative function may be part of the mechanism.¹⁴Measuring accommodative amplitude through facility gives you a dynamic picture of how well your patient can cope with their accommodative lag – how much stamina they have to maintain near point focus.

用n6或更小的字母向您的患者提供近点卡 - 我使用封闭桨的顶部与下降的字母尺寸，或豪威尔豪洛里亚卡的背面。这应该持有33-40厘米的习惯性工作距离。（在您的较短武装患者的下端！）抓住±1.50和±2.00脚蹼，并将负面边合并为-3.50。如果您没有脚蹼（并且您应该订购一些！）使用每只眼睛持有的松动试镜。您可以在每只手中保存+2.00和-2.00，以便在它们之间快速切换以进行下面描述的设施测试。

您的儿科或年轻的成人近视患者与他们的全距离更正，应该能够清除这种功率，就像你期望他们的正相关住宿/ B-Test（响应减去）结果达到类似的水平。这是迅速测量部分容纳幅度响应。然后放下±1.50并将±2.00脚蹼切换到加侧。再次，近距离清除+2.00是预期的负相关住宿/ B +测试结果。¹⁵翻转几次+2.00和-2.00以观察结果，观察一个或两侧的疲劳，或者在整个方面保持迅速清算。

通常商定的用于测量容纳设施的临床方案包括观察响应时间，如果按时测量将包括临床医生和患者的反应时间。⁴Your result can be qualitative and quantitative. I prefer to record qualitative observations rather than a number of cycles per minute for enhanced clinical detail – for example:

1. “Acc fac normal” – if both -3.50, +2.00 and -2.00 are cleared swiftly and consistently
2. “Acc fac normal on plus, slow on -3.50, fatigues to fail on -2”
3. “Acc fac normal on plus, failed -3.50, cleared -2 on cycles”

If patient 2 or 3 above has a lag of accommodation over +1.00, their results on accommodative facility testing indicate how much ‘petrol in the tank’ they have to account for the lag. Patient 2 is in bigger trouble than patient 3, because they showed an initial response to minus which fatigued to fail, whereas patient 3 consistently maintained lower levels of accommodative function (clearing -2.00). The old adage that there is many ways to skin a cat holds for many clinical techniques as well as record keeping – ultimately we need to know how our patient will functionally cope with accommodative demand through their day and you can adapt facility testing to evaluate this.

Click on thislink to read how to measure accommodative lag at near， 和这个link for advice on prescribing for accommodative dysfunctions.

要将更多信息化为我的BV诊断和管理的简化的双系统方法，您可以观看此视频题为Binocular Vision - easier than you think. This one hour lecture includes cases; details easy use of prism correction for vergence disorders; changes to BV in contact lens wear; and why BV matters - for reading and learning in kids, clinical problem solving, and myopia management. You can alsodownload my lecture notes here.