Impact of Children's Postural Variation on Viewing Distance and Estimated Visual Acuity

Evaluation of Lag of Accommodation with Full-Field Diffusion Optics Technology™ (DOT) Contrast Management Spectacle Lenses in Emmetropic Children

Purpose

To evaluate the impact on the lag of accommodation (LOA) in emmetropic children after short-term wear of full-field Diffusion Optics TechnologyTM (DOT) spectacle lenses, designed to modulate retinal contrast to control myopia progression.

Patients and Methods

This was a single-visit, prospective, randomized, subject-masked study of emmetropes (ametropes ±1.00D or less in each meridian) with no history of myopia control treatment. Unaided logMAR visual acuity was measured, and ocular dominance was determined using the sighting method. In a randomized order, participants wore plano full-field contrast management (DOT) spectacles (no clear central aperture) or control spectacles (standard single vision spectacle lenses). Each participant was given 5 minutes for adaptation to the respective lenses before open field autorefraction measurements were taken at 6 meters and 40 cm. Ten measurements were taken for each eye. Data were evaluated from the right eye and the dominant eye separately.

Results

A total of 30 participants (20 females and 10 males) with a mean age of 10.4 ± 2.8 (7 to 17) years completed the study. There was no significant difference in right eye mean LOA with contrast management spectacles 0.57 ± 0.39D versus control spectacles 0.62 ± 0.34D; Wilcoxon test, p = 0.37. For dominant eyes, LOA values were 0.60 ± 0.40D and 0.68 ± 0.33D with contrast management spectacles and control spectacles, respectively (p = 0.14). Additionally, no significant difference was observed in mean LOA between males and females or between age groups (7-11 years vs 12-17 years) for either right or dominant eyes with contrast management or control spectacles (all p > 0.05).

Conclusion

Full-field contrast management spectacle lenses had no significant effect on LOA compared to standard single vision spectacle lenses, indicating no differential impact on accommodative response over the short period of lens wear tested.

Effect of reading with a mobile phone and text on accommodation in young adults

Purpose

To investigate the effects of reading with mobile phone versus text on accommodation accuracy and near work-induced transient myopia (NITM) and its subsequent decay during near reading in young adults with mild to moderate myopia.

Methods

The refractions of 31 young adults were measured with an open-field autorefractor (WAM-5500, Grand Seiko) for two reading tasks with a mobile phone and text at 33 cm. The mean age of the young adults was 24.35 ± 1.80 years. The baseline refractive aspects were determined clinically with full distance refractive correction in place. The initial NITM and its decay time and accommodative lag were assessed objectively immediately after binocularly viewing a mobile phone or text for 40 min.

Results

The mean ± standard deviation (SD) initial NITM magnitude was greater for reading with text (0.23 ± 0.26 D) than for reading with mobile phone (0.12 ± 0.17 D), but there was no significant difference between the two reading tasks (p = 0.082). The decay time (median, first quartile, and third quartile) was 60 s (16, 154) and 70 s (32, 180) in the phone task and text task groups, respectively. There was also no significant difference in the decay time between the two reading types in general (p = 0.294). The accommodative lags of text tasks and mobile phones tasks were equivalent (1.27 ± 0.52 D vs 1.31 ± 0.64 D, p = 0.792).

Conclusion

There were no significant differences in accommodative lags and the initial NITM and its decay time between reading with a mobile phone and text in young adults.

Can Psychophysics Be Fun? Exploring the Feasibility of a Gamified Contrast Sensitivity Function Measure in Amblyopic Children Aged 4-9 Years

Routine assessments of the Contrast Sensitivity Function [CSF] could be useful for the diagnosis and monitoring of amblyopia. However, current CSF measures are not clinically practical, as they are too slow, too boring, and too uncomfortable to sustain a young child's interest. Here we assess the feasibility of a more gamified approach to CSF testing, in which a maximum likelihood psychophysical algorithm (QUEST+) is combined with a largely unconstrained user interface (no fixation target, head restraints, or discrete trials). Twenty-five amblyopes (strabismic, anisometropic, or mixed) aged 4.0–9.2 years performed the gamified CSF assessment monocularly (once per eye). The test required the child to “pop” (press) grating stimuli as they “bounced” around a tablet screen. Head tracking via the tablet's front-facing camera was used to adjust for variations in viewing distance post hoc. CSFs were fitted for each eye, and Area Under the CSF (AUCSF) computed as a summary measure of sensitivity. The results showed that AUCSF measurements were able to separate moderately and severely amblyopic eyes from fellow eyes (case-control effect), and to distinguish individuals with varying degrees of vision loss (dose effect). Even the youngest children exhibited no difficulties completing the test or comprehending what to do, and most children appeared to find the test genuinely enjoyable. Informal feedback from a focus group of older children was also positive, although potential shortcomings with the present design were identified. This feasibility study indicates that gamified, child-friendly vision assessments have promise as a future means of pediatric clinical assessment. Such measures could be particularly valuable for assessing children outside of conventional eye-care facilities (e.g., home-monitoring, school screening).