Bullimore Mark A, Reuter Kathleen S, Jones Lisa A, Mitchell G Lynn, Zoz Jessica, Rah Marjorie J
The Ohio State University College of Optometry, Columbus, OH 43210, USA.
Optom Vis Sci. 2006 Aug;83(8):594-604. doi: 10.1097/01.opx.0000230274.42843.28.
The Study of Progression of Adult Nearsightedness (SPAN) is a 5-year observational study to determine the risk factors associated with adult myopia progression. Candidate risk factors include: a high proportion of time spent performing near tasks, performing near tasks at a close distance, high accommodative convergence/accommodation (AC/A) ratio, and high accommodative lag.
Subjects between 25 and 35 years of age, with at least -0.50 D spherical equivalent of myopia (cycloplegic autorefraction), were recruited from the faculty and staff of The Ohio State University. Progression is defined as an increase in myopia of at least -0.75 D spherical equivalent as determined by cycloplegic autorefraction. Annual testing includes visual acuity, noncycloplegic autorefraction and autokeratometry, phoria, accommodative lag, response AC/A ratio, cycloplegic autorefraction, videophakometry, ultrasound, and partial coherence interferometry (IOLMaster). Participants' near activities were assessed using the experience sampling method (ESM). Subjects carried a pager for two 1-week periods and were paged randomly throughout the day. Each time they were paged, they dialed into an automated telephone survey and reported their visual activity at that time. From these responses, the proportion of time spent performing near work was estimated.
Three-hundred ninety-six subjects were enrolled in SPAN. The mean (+/- standard deviation) age at baseline was 30.7 +/- 3.5 years, 66% were female, 80% were white, 11% were black, and 8% were Asian/Pacific Islander. The mean level of myopia (spherical equivalent) was -3.54 +/- 1.77 D, the mean axial length by IOLMaster was 24.6 +/- 1.1 mm, and subjects were 1.7 +/- 4.0 Delta exophoric. Refractive error was associated with the number of myopic parents (F = 3.83, p = 0.023), and the number of myopic parents was associated with the age of myopia onset (chi2 = 13.78, p = 0.001). In a multivariate analysis, onset of myopia (early vs. late) still had a significant effect on degree of myopia (F = 115.1, p < 0.001), but the number of myopic parents was no longer significant (F = 0.65, p = 0.52). For the ESM, the most frequently reported visual task was computer use (mean, 18.9%; range, 0-60.0%) and, overall, subjects reported near work activity 34.1% of the time (range, 0-67.3%).
The design of SPAN and the baseline characteristics of the cohort have been described. Parental history of myopia is related to the degree of myopia at baseline, but this effect is mediated by the age of onset of myopia.
成人近视进展研究（SPAN）是一项为期5年的观察性研究，旨在确定与成人近视进展相关的风险因素。候选风险因素包括：进行近距离任务的时间占比高、在近距离进行近距离任务、高调节性集合/调节（AC/A）比率以及高调节滞后。
从俄亥俄州立大学的教职员工中招募年龄在25至35岁之间、等效球镜度至少为-0.50 D近视（睫状肌麻痹验光）的受试者。进展定义为通过睫状肌麻痹验光确定等效球镜度近视增加至少-0.75 D。年度检查包括视力、非睫状肌麻痹验光和自动角膜曲率测量、隐斜视、调节滞后、反应性AC/A比率、睫状肌麻痹验光、视频晶状体测量、超声和部分相干干涉测量法（IOLMaster）。使用经验抽样法（ESM）评估参与者的近距离活动。受试者携带传呼机两周，每天随机传呼。每次传呼时，他们拨打自动电话调查并报告当时的视觉活动。根据这些回答，估计进行近距离工作的时间占比。
396名受试者纳入SPAN。基线时的平均（±标准差）年龄为30.7±3.5岁，66%为女性，80%为白人，11%为黑人，8%为亚洲/太平洋岛民。平均近视水平（等效球镜度）为-3.54±1.77 D，IOLMaster测量的平均眼轴长度为24.6±1.1 mm，受试者有1.7±4.0棱镜度外隐斜。屈光不正与近视父母的数量相关（F = 3.83，p = 0.023），近视父母的数量与近视发病年龄相关（χ2 = 13.78，p = 0.001）。在多变量分析中，近视发病（早发与晚发）对近视度数仍有显著影响（F = 115.1，p < 0.001），但近视父母的数量不再显著（F = 0.65，p = 0.52）。对于ESM，最常报告的视觉任务是使用电脑（平均，18.9%；范围，0 - 60.0%），总体而言，受试者报告近距离工作活动时间占34.1%（范围，0 - 67.3%）。
已描述SPAN的设计和队列的基线特征。近视的家族史与基线时的近视程度相关，但这种影响由近视发病年龄介导。
