Abstract
Abstract: :
Purpose:The Study of Progression of Adult Nearsightedness (SPAN) is a five–year cohort study to determine the risk factors associated with adult myopia progression, particularly the amount of near activities undertaken. Methods:Subjects were recruited from the faculty and staff of the Ohio State University and attended for a baseline examination. Subjects will attend for five annual follow–up visits. Progression is defined as increase in myopia of at least –0.75 D spherical equivalent as determined by cycloplegic auto–refraction. Annual testing includes visual acuity, non–cycloplegic auto–refraction and auto–keratometry, phoria, accommodative lag, response AC/A ratio, cycloplegic auto–refraction, videophakometry, ultrasound, and partial coherence interferometry (IOLMaster). Participants’ near activities are assessed using the Experience Sampling Method (ESM). Subjects carry a pager for two one–week periods and are paged randomly throughout the day. Each time they are paged, they dial into an automated telephone survey and report their activity at that time. Results:Three–hundred ninety–six employees of the Ohio State University were enrolled in SPAN. The mean age is 30.7±3.5 years, 68% are female, 80% are Caucasian, and 77% have worn contact lenses. The mean level of myopia (MSE) is –3.50 ± 1.8 D, the mean axial length by IOL Master is 24.6 ± 1.1 mm, and subjects 1.6 ± 4.0 Δ exophoric. The mean subject response rate for the first week of ESM was 90.3% (range: 7.1% to 100%). Thirty–five percent of the subjects responded to all 56 pages. The most frequently reported visual task was computer use (mean, 18.2%; range, 0 to 59.2%). On average subjects reported reading 10.4% of the time (range, 0% to 37.7%). Other common tasks included distance tasks such as driving (14.2%), social interactions (12.0%), and TV (10.4%). Overall, subjects reported near work activity 43.8% of the time (range, 12.5% to 87.3%). Conclusions:Subjects are being followed for five years. The ESM response rates and variation in near work should allow us to evaluate near work as a risk factor for adult myopia progression.
Keywords: myopia • clinical (human) or epidemiologic studies: risk factor assessment • refractive error development