Effects of Blue-light Blocking Lens on Visual Functions
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 80
- 主要终点
- Contrast Sensitivity as Assessed by Mars Contrast Sensitivity Chart
研究概览
简要总结
Working Hypothesis: The blue-light blocking lens has no effect on the contrast sensitivity, accommodative response, color vision, and subjective grading of the quality of life and vision.
Purpose: To determine and compare the visual performances after wearing the blue-light blocking lenses in participants with and without presbyopia.
Methods: One hundred and sixty computer users (computer usage >2 hours/day) with (n=120, aged >40years) and without presbyopia (n=40, aged 18-35 years) will be recruited. Three pairs of ophthalmic lenses will be prescribed for the participants, in which one pair of them will be the blue-light blocking lenses (StressFree, Swisscoat, HK). The lenses will be used for intermediate vision (i.e., computer usage) in presbyopic group, and for distant vision in non-presbyopic group. The adaptation period for each pair of lenses will be 1 month. The pre- and post-treatment contrast sensitivity, accommodative response and color vision will be measured. The participants will also be asked to complete questionnaires about their quality of life and vision, and the performances of these ophthalmic lenses.
Significance: The blue-light blocking lens reflects the short-wavelength lights and protects the retina from "blue-light hazards"; however, blue lights are essential for various visual function and circadian rhythms. This study will evaluate the impact of the blue-light blocking lenses on visual function and quality of life, and determine whether the blue-light blocking lenses are good choices for extra ocular protection.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Other
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 18 Years 至 55 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •age: 18 to 35 years OR 40 to 55 years
- •daily computer usage over over 2 hours per day
排除标准
- •visual acuity worst than 0 logMAR
- •abnormal binocular and color vision
- •previous history of ocular surgeries
研究组 & 干预措施
Young adults
adults without presbyopia who aged 18-35 years
干预措施: clear lens with regular coating (Device)
Young adults
adults without presbyopia who aged 18-35 years
干预措施: regular coating lens with yellow tint (Device)
Young adults
adults without presbyopia who aged 18-35 years
干预措施: clear lens with blue-light blocking coating (Device)
Middle-aged adults
adults with presbyopia who aged over 40 years
干预措施: clear lens with regular coating (Device)
Middle-aged adults
adults with presbyopia who aged over 40 years
干预措施: regular coating lens with yellow tint (Device)
Middle-aged adults
adults with presbyopia who aged over 40 years
干预措施: clear lens with blue-light blocking coating (Device)
结局指标
主要结局
Contrast Sensitivity as Assessed by Mars Contrast Sensitivity Chart
时间窗: Every 1-month interval from the date of randomization, up to 3 months
Contrast sensitivity was measured using the Mars contrast sensitivity letter chart (Mars Perceptrix, Chappaqua, NY). One out of three charts differing in the letter combinations was selected randomly in order to avoid memorization of the charts. The chart was placed at 50 cm with each letter subtended 2° visual angle. We followed the recording procedures as specified by the manufacturer: participants were instructed to read the letters from high to low contrasts and the test ended when two consecutive errors were made. The contrast sensitivity was scored as the log contrast sensitivity of the last correct letter minus 0.04 log unit for every prior error. The test was administered under normal (room illumination, 400 lux) and glare conditions. A brightness acuity tester set at its medium light intensity level (100 foot lamberts) simulated the glaring condition. A higher mean indicates improved contrast sensitivity.
Color Vision as Assessed by the Farnsworth Munsell 100 Hue Test
时间窗: Every 1-month interval from the date of randomization, up to 3 months
The Farnsworth Munsell 100 hue test (X-Rite, USA) was used to evaluate colour vision. Each of the four trays consisted of 21 movable caps. Participants were asked to sort the randomly arranged caps following the hue order from the first to the last fixed caps. The total error score was calculated, as documented in the instruction manual, to quantify the accuracy of color discrimination. There are no defined endpoints to the "total error score" range. A lower score indicates improved color discrimination ability.
次要结局
- Self-assessment of Lens Performance Through Questionnaire(Every 1-month interval from the date of randomization, up to 3 months)