Rajagopalan Aruna S, Bennett Edward S, Lakshminarayanan Vasudevan
University of Illinois at Chicago, Chicago, IL, USA.
Optom Vis Sci. 2006 Aug;83(8):611-5. doi: 10.1097/01.opx.0000232185.00091.45.
The purpose of this study is to assess the visual performance of subjects wearing gas-permeable (GP) multifocal contact lenses, soft bifocal contact lenses, GP monovision lenses and spectacles.
The study included 32 subjects between the ages of 42 and 65 years wearing GP monovision, the Acuvue Bifocal (Vistakon), the Essentials GP Multifocal (Blanchard), and progressive addition lenses (PAL; spectacles group). There were eight subjects in each of these groups who were already wearing these modalities. Binocular low (18%) and high (95%) contrast acuities were recorded using the Bailey-Lovie chart; binocular contrast sensitivity from 1.5 to 18 cycles per degree (cpd) measured with the Vistech VCTS 6500 system, and monocular glare sensitivity at three luminance settings (400, 100, and 12 foot lamberts) was measured using the brightness acuity tester (BAT). Binocular near visual task performance (a modified version of letter counting method used in previous presbyopic studies) was also assessed.
For the contact lens-wearing groups, subjects wearing GP multifocals provided the best binocular high and low contrast acuity followed by soft bifocal wearers. There was relative parity between the binocular high and low contrast acuity with PAL and GP multifocal wearers. Monovision acuity, measured binocularly, was determined to be lower than the other three groups with this difference being most significant with high contrast acuity. Among contact lens-wearing groups, it was observed that GP multifocal lens wearers experienced the lowest amount of monocular disability glare followed by soft bifocal wearers and monovision wearers. Subjects wearing soft bifocal lenses and monovision demonstrated slightly reduced binocular contrast sensitivity at all spatial frequencies. In the contact lens groups, GP multifocal lens wearers had the highest binocular contrast sensitivity at all spatial frequencies, on parity with PAL wearers, except at the highest spatial frequency (18 cpd) at which PAL wearers had better vision. Error scores for the binocular near visual task performance between the four groups revealed subjects with GP multifocal lenses and PAL wearers to have the least errors, followed by monovision users and then soft bifocal wearers with the most errors.
Subjects wearing GP multifocals, soft bifocals, monovision, and PAL spectacles have good binocular contrast sensitivity, satisfactory binocular low and high contrast acuity, and increased sensitivity to glare. Presbyopic subjects requiring the use of contact lenses under dim light levels could benefit from GP multifocal lenses. Contrast and glare sensitivity evaluations provide significant information regarding the visual performance of the presbyopic contact lenses and should be included in regular presbyopic contact lens fitting.
本研究旨在评估佩戴透气性（GP）多焦点隐形眼镜、软性双焦点隐形眼镜、GP单眼视力隐形眼镜和眼镜的受试者的视觉表现。
该研究纳入了32名年龄在42至65岁之间的受试者，他们分别佩戴GP单眼视力镜片、酷柏双焦点隐形眼镜（视康）、精华GP多焦点隐形眼镜（布兰查德）和渐进多焦点镜片（PAL；眼镜组）。每组有八名受试者已经在佩戴这些矫正方式。使用贝利-洛维视力表记录双眼低对比度（18%）和高对比度（95%）视力；使用伟视德VCTS 6500系统测量1.5至18周/度（cpd）的双眼对比敏感度，并使用亮度视力测试仪（BAT）在三种亮度设置（400、100和12英尺朗伯）下测量单眼眩光敏感度。还评估了双眼近视力任务表现（先前老花眼研究中使用的字母计数法的改良版）。
对于佩戴隐形眼镜的组，佩戴GP多焦点镜片的受试者双眼高对比度和低对比度视力最佳，其次是佩戴软性双焦点镜片的受试者。PAL佩戴者和GP多焦点镜片佩戴者的双眼高对比度和低对比度视力相对相当。双眼测量的单眼视力被确定低于其他三组，这种差异在高对比度视力时最为显著。在佩戴隐形眼镜的组中，观察到佩戴GP多焦点镜片的受试者单眼残疾眩光量最低，其次是佩戴软性双焦点镜片的受试者和单眼视力佩戴者。佩戴软性双焦点镜片和单眼视力的受试者在所有空间频率下的双眼对比敏感度略有降低。在隐形眼镜组中，GP多焦点镜片佩戴者在所有空间频率下的双眼对比敏感度最高，与PAL佩戴者相当，但在最高空间频率（18 cpd）时，PAL佩戴者视力更好。四组之间双眼近视力任务表现的错误分数显示，佩戴GP多焦点镜片的受试者和PAL佩戴者错误最少，其次是单眼视力使用者，然后是软性双焦点镜片佩戴者，错误最多。
佩戴GP多焦点镜片、软性双焦点镜片、单眼视力镜片和PAL眼镜的受试者具有良好的双眼对比敏感度、令人满意的双眼低对比度和高对比度视力，以及对眩光的更高敏感度。在暗光条件下需要使用隐形眼镜的老花眼受试者可能会从GP多焦点镜片中受益。对比度和眩光敏感度评估提供了有关老花眼隐形眼镜视觉表现的重要信息，应纳入常规的老花眼隐形眼镜验配中。
