Day Mhairi, Strang Niall C, Seidel Dirk, Gray Lyle S
Department of Vision Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, UK.
Ophthalmic Physiol Opt. 2008 Jan;28(1):91-5. doi: 10.1111/j.1475-1313.2007.00522.x.
Dynamic measurement of accommodation in subjects with myopia usually involves recording through soft contact lenses (CLs) to correct the refractive error. Conversely, dynamic accommodation measurement in emmetropic control subjects is generally undertaken without any corrective lenses. The aim of this experiment was to determine whether CL correction affects the measurement of accommodation microfluctuations using infrared refractometry, and whether this needs to be considered in studies which attempt to compare accommodation responses between the two groups.
Ten young emmetropic subjects viewed a high contrast Maltese cross target monocularly using the right eye at a target vergence of 0 D. The subjects viewed the target under two conditions: with CL condition and without CL condition, where the subjects viewed the target with the eye only. Accommodation responses of the right eye were recorded continuously for 2 min at a sampling rate of 52 Hz using the Shin-Nippon SRW-5000 autorefractor.
No significant difference (two-tailed paired t-test, t(9) = -1.499, p = 0.168) was found in mean accommodation response between the with CL (mean +/- S.D. = -0.02 +/- 0.24 D) and without CL conditions (mean +/- S.D. = +0.01 +/- 0.25 D). No significant (two-tailed paired t-test, t(9) = 0.151, p = 0.883) difference in the magnitude of the accommodation microfluctuations was found between the with CL (mean +/- S.D. = 0.162 +/- 0.04 D) and without CL condition (mean +/- S.D. = 0.169 +/- 0.04 D). Power spectrum analysis revealed no differences in the characteristics of the microfluctuations waveform between the two conditions. A control experiment carried out on a subgroup of five subjects using a negative (-3 D) CL demonstrated that there was no significant effect of the dioptric power of the CL on the magnitude of the accommodation microfluctuations (anova: F(3,15) = 0.254, p = 0.782).
Thin soft CLs do not affect the magnitude or frequency characteristics of accommodation microfluctuations when measured using the Shin-Nippon SRW-5000.
近视患者调节功能的动态测量通常需要通过软性接触镜（CL）进行记录以矫正屈光不正。相反，正视对照受试者的动态调节测量一般在不使用任何矫正镜片的情况下进行。本实验的目的是确定CL矫正是否会影响使用红外验光法测量的调节微波动，以及在试图比较两组间调节反应的研究中是否需要考虑这一点。
10名年轻正视受试者单眼使用右眼以0 D的目标聚散度观察高对比度马耳他十字视标。受试者在两种条件下观察视标：戴CL条件和不戴CL条件，即受试者仅用眼睛观察视标。使用日本新日本SRW-5000自动验光仪以52 Hz的采样率连续记录右眼2分钟的调节反应。
戴CL条件下（平均值±标准差=-0.02±0.24 D）和不戴CL条件下（平均值±标准差=+0.01±0.25 D）的平均调节反应之间未发现显著差异（双侧配对t检验，t(9)=-1.499，p=0.168）。戴CL条件下（平均值±标准差=0.162±0.04 D）和不戴CL条件下（平均值±标准差=0.169±0.04 D）的调节微波动幅度未发现显著差异（双侧配对t检验，t(9)=0.151，p=0.883）。功率谱分析显示两种条件下微波动波形特征无差异。对5名受试者的亚组使用负度数（-3 D）CL进行的对照实验表明，CL的屈光度对调节微波动幅度无显著影响（方差分析：F(3,15)=0.254，p=0.782）。
使用日本新日本SRW-5000测量时，薄软性CL不会影响调节微波动的幅度或频率特征。
