Altoaimi Basal H, Kollbaum Pete, Meyer Dawn, Bradley Arthur
School of Optometry, Indiana University, Bloomington, USA.
Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
Ophthalmic Physiol Opt. 2018 Mar;38(2):152-163. doi: 10.1111/opo.12438. Epub 2018 Jan 8.
Multifocal or multi-zone contact lenses are increasingly being fit to young eyes in an attempt to control myopia progression. However, success in achieving this aim may depend on how much the eye accommodates. The purpose of the current work was to evaluate the ability of an open-field clinical autorefractor to measure on-axis refractive state and accommodation in eyes fit with multifocal contact lenses (CLs).
Refractive state was measured with a Grand Seiko WAM-5500 autorefractor (www.grandseiko.com) and a clinical Shack-Hartmann Complete Ophthalmic Analysis System (COAS) aberrometer (www.wfsci.com) in subjects fit bilaterally with single vision aspheric contact lenses, centre distance, and centre near zonal multifocal CLs, and an experimental myopia control multi-zone bifocal CLs (MiSight). Autorefractor measurements were obtained when aligned with the pupil centre, pupil margin, and mid-periphery. Accuracy of refractive state measurements was evaluated using a fully presbyopic (62-year-old) dilated (pupil diameter = 7.1 mm) eye measured through known added spherical powers (trial lenses) of +1.00 D to +6.00 D. Refractive state and accommodation were measured for seven young myopic eyes (23.71 ± 2.87 years) with six target vergences ranging from -0.33 D to -5.00 D.
Irrespective of the CL fitted, measured changes in refractive state of the calibration eye were within ≤0.25 D of the added sphere power and the slope (measured refractive state/trial lens power) was approximately -1.0 D/D for both Shack-Hartmann (COAS) aberrometer and Grand Seiko instruments. Also, the Grand Seiko data were highly repeatable (mean measurement standard deviation = 0.04 D) as long as measurements occurred at the same pupil location, but exhibited a hyperopic bias that increased to +1.00 D when eyes were fit with CLs containing significant negative spherical aberration. Centre and marginal refractive states could differ by >3.00 D due to the combined spherical aberration contained in the eye plus the different CL designs. Measured refractive states of young accommodating eyes also varied with measurement location in the pupil. The accommodation gains were similar at each pupil location, irrespective of contact lens design.
With consistent sampling at the same pupil location, the open field Grand Seiko clinical autorefractor proved an effective tool for assessing the on-axis refractive state and accommodative responses of eyes fit with multi-zone bifocal and multifocal CLs.
多焦点或多区域隐形眼镜越来越多地被用于年轻眼睛，试图控制近视进展。然而，实现这一目标的成功与否可能取决于眼睛的调节程度。当前研究的目的是评估开放式临床自动验光仪测量佩戴多焦点隐形眼镜（CL）的眼睛的轴上屈光状态和调节的能力。
使用Grand Seiko WAM - 5500自动验光仪（www.grandseiko.com）和临床Shack - Hartmann全眼分析系统（COAS）像差仪（www.wfsci.com）测量屈光状态，受试者双侧佩戴单焦点非球面隐形眼镜、中心距离和中心近区多焦点CL，以及一种实验性近视控制多区域双焦点CL（MiSight）。当与瞳孔中心、瞳孔边缘和中周边对齐时获取自动验光仪测量值。使用通过 +1.00 D至 +6.00 D的已知附加球镜度（试验镜片）测量的一只完全老花眼（62岁）散瞳（瞳孔直径 = 7.1 mm）眼睛评估屈光状态测量的准确性。测量了七只年轻近视眼睛（23.71 ± 2.87岁）在六个从 -0.33 D至 -5.00 D的目标屈光参差下的屈光状态和调节。
无论佩戴何种CL，校准眼睛测量的屈光状态变化在附加球镜度的≤0.25 D范围内，并且对于Shack - Hartmann（COAS）像差仪和Grand Seiko仪器，斜率（测量的屈光状态/试验镜片度数）均约为 -1.0 D/D。此外，只要测量在相同瞳孔位置进行，Grand Seiko数据具有高度可重复性（平均测量标准差 = 0.04 D），但当眼睛佩戴含有显著负球差的CL时，表现出远视偏差，偏差增加到 +1.00 D。由于眼睛中包含的组合球差加上不同的CL设计，中心和边缘屈光状态可能相差>3.00 D。年轻调节眼睛测量的屈光状态也随瞳孔中的测量位置而变化。无论隐形眼镜设计如何，每个瞳孔位置的调节增益相似。
在相同瞳孔位置进行一致采样时，开放式Grand Seiko临床自动验光仪被证明是评估佩戴多区域双焦点和多焦点CL的眼睛的轴上屈光状态和调节反应的有效工具。
