B C Jiang1. 1. College of Optometry, University of Houston, TX 77204-6052, USA.
Abstract
PURPOSE: To evaluate whether the characteristics of the oculomotor system are related to the development of late-onset myopia. METHODS: Forty-four college students were followed for 2 to 3 years. When recruited, 33 of the 44 subjects had emmetropia whereas the remainder (N = 11) had late-onset myopia (LOM). For each subject, dark-focus, dark-vergence, response AC/A, and CA/C ratios, and manifest refraction were measured at 6-month intervals. RESULTS: The mean dark-focus and AC/A ratios for the subjects (N = 6) who started with emmetropia and became myopic were higher than for the subjects (N = 25) who remained emmetropic. These higher values presented before the refractions exceeded -0.50 D. Interestingly, 7 of 11 subjects with LOM whose myopia increased displayed higher mean AC/A and dark-vergence values and lower mean dark-focus values than the subjects who remained emmetropic. CONCLUSION: The lower dark-focus values found among subjects with LOM seems to be a consequence of the development of myopia. However, myopia might eventually develop in a person with emmetropia with a relatively high AC/A and/or dark-focus values. Therefore, AC/A and dark-focus values may be predictors of the development of myopia.
PURPOSE: To evaluate whether the characteristics of the oculomotor system are related to the development of late-onset myopia. METHODS: Forty-four college students were followed for 2 to 3 years. When recruited, 33 of the 44 subjects had emmetropia whereas the remainder (N = 11) had late-onset myopia (LOM). For each subject, dark-focus, dark-vergence, response AC/A, and CA/C ratios, and manifest refraction were measured at 6-month intervals. RESULTS: The mean dark-focus and AC/A ratios for the subjects (N = 6) who started with emmetropia and became myopic were higher than for the subjects (N = 25) who remained emmetropic. These higher values presented before the refractions exceeded -0.50 D. Interestingly, 7 of 11 subjects with LOM whose myopia increased displayed higher mean AC/A and dark-vergence values and lower mean dark-focus values than the subjects who remained emmetropic. CONCLUSION: The lower dark-focus values found among subjects with LOM seems to be a consequence of the development of myopia. However, myopia might eventually develop in a person with emmetropia with a relatively high AC/A and/or dark-focus values. Therefore, AC/A and dark-focus values may be predictors of the development of myopia.
Authors: Mark A Bullimore; Kathleen S Reuter; Lisa A Jones; G Lynn Mitchell; Jessica Zoz; Marjorie J Rah Journal: Optom Vis Sci Date: 2006-08 Impact factor: 1.973
Authors: Donald O Mutti; G Lynn Mitchell; Lisa A Jones-Jordan; Susan A Cotter; Robert N Kleinstein; Ruth E Manny; J Daniel Twelker; Karla Zadnik Journal: Invest Ophthalmol Vis Sci Date: 2017-03-01 Impact factor: 4.799