Abstract
Abstract: :
Purpose: We are conducting a five-year cohort study to determine the risk factors associated with adult myopia progression. Progression is defined as an increase in myopia of at least -0.75 D spherical equivalent as determined by cycloplegic auto-refraction. The risk factors to be evaluated include: a high proportion of time spent performing near tasks, performing near tasks at a closer distance, high AC/A ratio, and high accommodative lag. Here we present two-year follow-up data from the pilot study. Methods: Subjects between 25 and 35 years of age, with at least -0.50 D of myopia, were recruited from the faculty and staff of The Ohio State University. Annual testing included 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. Participants’ near work is assessed using the Experience Sampling Method. 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. From these responses, the proportion of time spent performing near work can be estimated. Results: Sixty-five subjects with mean age of 33.8 1.69 years were recruited for the pilot study (60% female, 81.5% Caucasian, 10.8% African-American). Thirty-two (49.2%) wore contact lenses. At baseline, the mean refractive error was -3.87 1.62 D. Twenty-eight subjects have completed 2 years of follow-up. The mean 2-year change in refractive error was -0.03 0.28 D. The mean 2-year change in axial length was -0.03 0.31mm. Response rates for the Experience Sampling Method have been excellent: in year 2, the mean response rate was 89.6%. Conclusion: Recruitment of a larger group of subjects is currently underway. To date 153 subjects have been recruited. The high response rate for the Experience Sampling Method should allow accurate characterization of near work activities in the cohort and the evaluation of near work as a risk factor for adult myopia progression.
Keywords: 481 myopia • 355 clinical (human) or epidemiologic studies: risk factor assessment • 304 accommodation