Abstract
Purpose :
To investigate the association between myopic progression and myopia risk factors such as refractive status and accommodative functions in Chinese children and young adults.
Methods :
159 children and young adults (age 12.52±1.97 years, from 8 to 19 years) were enrolled in the study. The mean of spherical equivalent refraction (SER) was -3.16±1.17D, ranging from -0.75 to -6.88DS, and astigmatism was less than 1.50DC. Refractive errors were corrected by trial frames. Continuous accommodative stimulus-response curves were measured by a Grand Seiko WAM-5500 autorefractor with a motorized Badal system mounted on, and were fitted with a 3-degree polynomial equation. Accommodative error area, defined as the area between the stimulus-response curve and 1:1 line, was calculated between 1 and 6 D stimulus proximity. The slope of the accommodative response was defined as the steepest slope of the polynomial function. Objective accommodative amplitude (AA) was defined as the difference between maximum and the minimum accommodative response. Monocular distance accommodative facility (DAF) was measured using a Plano/-2.00 D lens combination mounted in a flipper with the subject viewing 20/30 letters placed at 4.5m. The average of myopic progression per year was calculated according to the history of refractive results of the last two visits.
Results :
Myopic progression was -0.86±0.41D per year, accommodative error area was 6.10 ± 1.66 D2, DAF was 17.82 ± 7.14 cpm, slope was 0.92 ± 0.06, and objective AA was 7.65 ± 1.68D. Myopic progression was associated with age (t = 5.14, p < 0.001), SER (t = 2.45, p = 0.02) and DAF (t = 2.23, p = 0.03) (Progression per year = 0.082*AGE + 0.067*SER+ 0.009*DAF -1.840, R2 = 0.18). Accommodative error area (t = -1.43, p = 0.15), slope (t = 0.82, p = 0.42) and objective AA (t = -1.14, p = 0.26) were not linked to myopic progression.
Conclusions :
Younger age, higher myopia and less flexible distance accommodative facility were associated with higher myopic progression. However, age, SER and distance accommodative facility explained only 18% of variance of myopic progression. Accommodative error area, slope and objective accommodative amplitude did not impact myopic progression, suggesting that accommodation weakly affected myopia progression in our sample.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.