Comparison of the effects of different chromatic lights on accommodative response and microfluctuation in myopes and emmetropes / 中华实验眼科杂志

Objective:To explore the effects of conflicting stimuli generated by different chromatic lights on visual display terminal (VDT) on accommodative response and microfluctuation of myopes and emmetropes, and to investigate the possible relationship between chromatic light, accommodation and the development and progression of myopia.Methods:A non-randomized controlled trial was conducted.Forty-one subjects aged 22 to 30 years old were enrolled, including 19 emmetropes in emmetropic group and 22 myopes in myopic group.The subjects had the normal color vision and no ocular organic diseases.The interventions were screens of different colors.There were 7 chromatic light conditions, including 3 monochromatic lights (red, green, blue), 3 bichromatic lights (red+ green, red+ blue, green+ blue) and 1 polychromatic light (white=red+ green+ blue). Subjects were asked to look at a black E target on a VDT at a distance of 33 cm for more than 20 seconds.The background color of the VDT was changed randomly in the 7 chromatic light conditions.The accommodative responses were recorded with the Grand Seiko WAM-5500 automatic infrared refractor every 0.2 seconds and the accommodative microfluctuation was calculated as the standard deviation of the accommodative response.Accommodative response and accommodative microfluctuation under different chromatic light conditions were compared.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the First Affiliated Hospital, Zhejiang University School of Medicine (No.2019-1564). Written informed consent was obtained from each subject.Results:No statistically significant difference was found in the accommodative response between the two groups ( Fgroup=2.626, P=0.113). There was a statistically significant difference under different chromatic light conditions between the two groups ( Flight=39.070, P<0.01). There were similar trends in the effects of various color lights in both groups, with the largest accommodative response under monochromatic red light, followed by the bichromatic light containing red light, and then the smallest accommodative response under monochromatic blue light, and the differences were statistically significant (all at P<0.05). The accommodative microfluctuations under red, green, blue, red+ blue, red+ green, blue+ green and white light conditions were (0.142±0.033), (0.128±0.038), (0.131±0.043), (0.139±0.039), (0.127±0.034), (0.131±0.043) and (0.139±0.042)D in emmetropic group, and (0.178±0.043), (0.164±0.043), (0.159±0.039), (0.174±0.042), (0.166±0.036), (0.159±0.031) and (0.174±0.035)D in myopic group, respectively, showing statistically significant differences between them ( Fgroup=12.146, P<0.01; Flight=2.782, P<0.05). The accommodative microfluctuations under the 7 light conditions were higher in myopic group than in emmetropic group, and the differences were statistically significant (all at P<0.05). In myopes, the accommodative microfluctuation was the largest under red light, which was significantly larger than that under blue light, and was the smallest under blue+ green light (all at P<0.05). There was no significant difference in the accommodative microfluctuation between bichromatic light and its two monochromatic lights, or between the polychromatic light (white light) and its three monochromatic lights (all at P>0.05). There was no significant effect of various chromatic lights on the accommodative microfluctuation in emmetropic group (all at P>0.05). Conclusions:The accommodative microfluctuation is greater in myopes than in emmetropes.The stimuli produced by long-wavelength light cause larger accommodative microfluctuation, while conflicting stimuli generated by different chromatic lights do not increase accommodative microfluctuation.

The Relationship between the High-Frequency Component of Accommodative Microfluctuation, Accommodative Lag and Accommodative Amplitude in Presbyopic Eyes

PURPOSE: To determine the relationship between the high-frequency component of accommodative microfluctuation (HFC) and accommodative lag in presbyopic eyes and how they affect the subjective accommodation power with other ophthalmic factors, such as pupil diameter and corneal multifocality. METHODS: Forty subjects (80 eyes) were included in this study, and the non-corrected distance and near visual acuity was measured and then converted to log MAR vision. The addition power for 33 cm near visual work was also measured and the accommodative power was measured by the push-up method. The HFC, accommodative lag and pupil size according to accommodative stimuli (-1.0 to -3.0 D) was measured by Speedy-i Autorefractor (Right Mfg Co., Tokyo). The corneal multifocality and corneal astigmatism was measured by corneal topography (TMS-4; Tomey, Erlangen, Germany). RESULTS: The mean age was 60.0 +/- 4.66 years (51-68) and there were 23 male and 17 female subjects (1.35:1). The HFC and pupil size showed no significant change according to accommodation demand, however, the accommodative lag showed a statistically significant increase (p < 0.001 by one-way ANOVA). Accommodative lag (-2.0 D) showed a statistically significant negative correlation with the subjective accommodative power, and the pupil size (0 D) showed a positive correlation with the subjective accommodative power. CONCLUSIONS: In presbyopia patients, the objective accommodative lag and initial pupil size showed a statistically significant relationship with subjective accommodative power. On the other hand, HFC, pupil size and corneal multifocality, alone may not be indicators to predict accommodative power, but these are important components to explain the dynamic aspect of accommodation.

The influence of the presents of target and watching ways on the level and amplitude of accommodative fluctuation / 中华实验眼科杂志

Background Researches showed that as the non-optical factors,cognitive has certain influence on the regulating system.So accurately experimental design is one of the key steps that evaluates the non-optical factors on regulating system.Objective The present study was to investigate the influence of presenting pattern of target and watching way on the level and amplitude of accommodative fluctuate and to analyze the effect of focus gaze of cognitive on regulating system and the relationship between focus gaze condition under near work and the development of myopia.Methods This study complied with Declaration of Helsinki,and the permission of Ethic Committee and written informed consent was obtained before entering in this trial.Thirty healthy volunteers were included with the mean age (24.80 ± 1.98) years old,equivalent refractive diopter (-1.92 ± 2.02) D and mean cylinder (-0.19±0.58) D.The presenting pattern of the targets was designed as focus gaze and relaxed gaze.The accommodative response and accommodative fluctuation in the complete corrected right eyes for the different targets at the 40 cm under the gazing state was recorded with Grand Seiko WAM 5500 automatic infrared refractor in the experiment.Results The mean accommodative response value was (1.86±0.26) D under the focus gaze and (1.27±0.39) D under the relax gaze,showing a statistically significant difference (t=-8.052,P=0.000).The mean fluctuate value was(0.17±0.06) D under the focus gaze,with a significant lowing in comparison with (0.28±0.17) D under the relax gaze (t =3.600,P =0.001).Conclusions These results demonstrate that the different presenting patterns of sighting target and watching ways of the subjects affect accommodation system.The accommodative response was relatively more accurate with a smaller microwavc moving under the focus gaze condition.