Brady Christopher J, Eghrari Allen O, Labrique Alain B
Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Department of International Health and Department of Epidemiology, Bloomberg School of Public Health, Baltimore, Maryland.
JAMA. 2015;314(24):2682-3. doi: 10.1001/jama.2015.15855.
Visual acuity is the most frequently performed measure of visual function in clinical practice and most people worldwide living with visual impairment are living in low- and middle-income countries.
To design and validate a smartphone-based visual acuity test that is not dependent on familiarity with symbols or letters commonly used in the English language.
DESIGN, SETTING, AND PARTICIPANTS: Validation study conducted from December 11, 2013, to March 4, 2014, comparing results from smartphone-based Peek Acuity to Snellen acuity (clinical normal) charts and the Early Treatment Diabetic Retinopathy Study (ETDRS) logMAR chart (reference standard). This study was nested within the 6-year follow-up of the Nakuru Eye Disease Cohort in central Kenya and included 300 adults aged 55 years and older recruited consecutively.
Outcome measures were monocular logMAR visual acuity scores for each test: ETDRS chart logMAR, Snellen acuity, and Peek Acuity. Peek Acuity was compared, in terms of test-retest variability and measurement time, with the Snellen acuity and ETDRS logMAR charts in participants’ homes and temporary clinic settings in rural Kenya in 2013 and 2014.
The 95%CI limits for test-retest variability of smartphone acuity data were ±0.029 logMAR. The mean differences between the smartphone-based test and the ETDRS chart and the smartphone-based test and Snellen acuity data were 0.07 (95%CI, 0.05–0.09) and 0.08 (95%CI, 0.06–0.10) logMAR, respectively, indicating that smartphone-based test acuities agreed well with those of the ETDRS and Snellen charts. The agreement of Peek Acuity and the ETDRS chart was greater than the Snellen chart with the ETDRS chart (95%CI, 0.05–0.10; = .08). The local Kenyan community health care workers readily accepted the Peek Acuity smartphone test; it required minimal training and took no longer than the Snellen test (77 seconds vs 82 seconds; 95%CI, 71–84 seconds vs 73–91 seconds, respectively; = .13).
The study demonstrated that the Peek Acuity smartphone test is capable of accurate and repeatable acuity measurements consistent with published data on the test-retest variability of acuities measured using 5-letter-per-line retroilluminated logMAR charts.
视力是临床实践中最常进行的视觉功能测量指标，全球大多数视力受损者生活在低收入和中等收入国家。
设计并验证一种不依赖于对英语中常用符号或字母熟悉程度的基于智能手机的视力测试。
设计、背景和参与者：2013年12月11日至2014年3月4日进行的验证研究，比较基于智能手机的Peek视力测试结果与斯内伦视力表（临床标准）以及早期糖尿病视网膜病变研究（ETDRS）对数视力表（参考标准）。该研究嵌套于肯尼亚中部纳库鲁眼病队列的6年随访中，连续招募了300名55岁及以上的成年人。
每个测试的结局指标为单眼对数视力表视力得分：ETDRS视力表对数视力、斯内伦视力和Peek视力。2013年和2014年，在肯尼亚农村参与者家中和临时诊所环境中，就重测变异性和测量时间而言，将Peek视力与斯内伦视力和ETDRS对数视力表进行比较。
智能手机视力数据重测变异性的95%CI范围为±0.029对数视力。基于智能手机的测试与ETDRS视力表以及基于智能手机的测试与斯内伦视力数据之间的平均差异分别为0.07（95%CI，0.05 - 0.09）和0.08（95%CI，0.06 - 0.10）对数视力，表明基于智能手机的测试视力与ETDRS和斯内伦视力表的视力高度一致。Peek视力与ETDRS视力表的一致性大于斯内伦视力表与ETDRS视力表的一致性（95%CI，0.05 - 0.10；P = 0.08）。肯尼亚当地社区卫生工作者很容易接受Peek视力智能手机测试；它所需培训极少，且所用时间不超过斯内伦测试（分别为77秒对82秒；95%CI，71 - 84秒对73 - 91秒；P = 0.13）。
该研究表明，Peek视力智能手机测试能够进行准确且可重复的视力测量，与使用每行5个字母的反光对数视力表测量的视力重测变异性的已发表数据一致。
