Effects of Optical Correction Method on the Magnitude and Variability of Accommodative Response: A Test-retest Study

Abstract

SIGNIFICANCE The present study addresses the accommodative response and its dependence on the type of optical correction used. The results are discussed relative to their possible implications for myopia progression and visual fatigue. PURPOSE The accommodative response has been investigated owing to its possible relationship with the onset and progression of myopia and visual fatigue. This study explored the influence of wearing soft contact lenses in comparison with spectacles in terms of magnitude and variability of accommodation. In addition, we analyzed the intersession and intermethod repeatability. METHODS Dynamic accommodative response was recorded during 30-second epochs, at five different distances (50, 40, 33, 25, and 20 cm), in 21 individuals (mean refractive error ± SD, −0.79 ± 1.39 D) while wearing either soft contact lenses or spectacles on two different days. To assess repeatability, a second identical intervention was conducted. RESULTS Higher lags of accommodation were obtained with the use of soft contact lenses in comparison with the spectacle condition (P = .04, partial η2 [ηp 2] = 0.204), and similarly, a higher variability of accommodation at near distances was found during the soft contact lens measurement (P < .001, ηp 2 = 0.647). There was a strong intersession repeatability at all the distances tested for both optical correction methods. CONCLUSIONS The higher accommodative lag and fluctuations found while wearing soft contact lenses in comparison with spectacles may help to understand the mechanisms underlying myopia progression and asthenopia. These findings may be also considered when testing the accommodative response in research settings. Our test-retest design confirmed that there is a very good intersession repeatability for all the distances in both optical correction methods.

Dynamics of the accommodative response after smoking cannabis

“…The dynamics of the accommodative response were then evaluated by means of an open field autorefractor, the Grand Seiko WAM‐5500 (Grand Seiko, http://grandseiko.com), which has been shown to be reliable and valid for assessing accommodation in both static and dynamic modes 41‐43 …”

“…Accommodative lag was obtained in accordance with Poltavski et al ., 51 by subtracting the mean point of focus during testing (WAM‐5500 refraction value) from the target distance (2.25 D or 4.75 D) and adjusting for the baseline static refraction value (taken at 4.5 m). In addition, the standard deviation of the accommodative response corresponded to the variability of accommodation 42,52,53,54 . In order to ensure that the accommodative response had a steady state, its variability was calculated for the 5 central seconds of the 10 s accommodation intervals in each cycle.…”

“…com), which has been shown to be reliable and valid for assessing accommodation in both static and dynamic modes. [41][42][43] We used the dynamic (HI-SPEED) mode, with a sample frequency of 5 Hz and a sensitivity of 0.01 D. The device also registered pupil size with a sensitivity of 0.1 mm. The measurements were taken from one eye (randomly selected), 44 while subjects viewed the target binocularly.…”

“…In addition, the standard deviation of the accommodative response corresponded to the variability of accommodation. 42,52,53,54 In order to ensure that the accommodative response had a steady state, its variability was calculated for the 5 central seconds of the 10 s accommodation intervals in each cycle. Therefore, a total of 15 s of recording was used to obtain the mean accommodation variability in each measurement.…”