Accommodative Lag Research Articles

Effect of a vergence-accommodation conflict induced during a 30-minute Virtual Reality game on vergence-accommodation parameters and related symptoms

PurposeThe aim of the study was to verify the hypotheses that vergence-accommodation conflict (VAC) induced with head-mounted device (HMD) could cause symptoms in relation to changes in the accommodative-vergence system. In order to test this hypothesis, the Virtual Reality (VR) exposures were carried out in two types of VAC: VACsmall and VAClarge. MethodEighteen females, with a mean age of 22.5 ± 2.0 years, participated in two 30-minutes sessions with VR, which were separated by at least one week. Two sessions were differentiated by intensity of VAC presented in the VR system (VACsmall and VAClarge). Visual parameters were measured such as associated and dissociated phoria, accommodative response, the near point of convergence (NPC), fusional vergence ranges (FVR) and subjective complaints were measured using Simulator Sickness Questionnaire (SSQ). The parameters were measured immediately before (Pre-test) and after (Post-test) the VR exposure. ResultsThe subjective symptoms as nausea, oculomotor disorders and disorientation increased significantly after 30-minutes of exposure on VAClarge (P<0.05). The associated and dissociated phoria, lag of accommodation, FVR and the NPC did not significantly change after the VR exposure (P>0.05). ConclusionShort-term use of HMD (30-min) did not significantly affect accommodative-vergence functions regardless of the size of VAC (VACsmall and VAClarge). However, the level of symptoms increased after VR sessions, which was probably related to inappropriate oculo-vestibular relationship.

Effects of Two Vision Therapy Approaches on Accommodative Insufficiency and Post-therapy Stability.

To evaluate the effect of the EYEPORT II vision training system (Bernell) on accommodation in cases of accommodative insufficiency. The experimental study was conducted in a binocular vision clinic. Of 230 patients, 36 were eligible and willing to participate in office-based therapy. Participants were randomly divided into two groups: control and EYEPORT. The control group received conventional therapy and the EYEPORT group received conventional therapy combined with the EYEPORT II vision training device. The therapy lasted for 1 hour daily over 6 days in a week, with 24 sessions administered over 4 weeks. Accommodative parameters were reevaluated 2 weeks, 4 weeks, and 24 months after treatment. The study included 19 men and 17 women, with a median age of 27.50 years. After 24 sessions of vision therapy, accommodative parameters improved significantly, with more pronounced results compared with baseline measurements, as demonstrated by the Wilcoxon signed-rank test (P < .05). The Mann-Whitney U test indicated a significant (P < .05) improvement in treatment outcomes for the EYEPORT group using the EYEPORT device together with conventional therapy. The median accommodation amplitude increased by 6.95 diopters (D), the accommodation lag decreased by -0.25 D, the positive relative accommodation improved by -1.63 D, and the accommodative facility increased by 13 cycles/minute. After 3 months without therapy, the treatment outcome was maintained. Office-based vision therapy can effectively treat accommodative insufficiency. Both groups showed improvement in the accommodative amplitude and other parameters. The EYEPORT group was more stable at 3 months. [J Pediatr Ophthalmol Strabismus. 20XX;XX(X):XXX-XXX.].

Practice patterns in pediatric myopia management: Insights from a 2023 survey among Indian ophthalmologists.

This study investigates the practice patterns related to paediatric myopia among Paediatric Ophthalmologists in India, based on a 2023 survey conducted via Google Forms. The survey aimed to gather insights into physicians' perceptions and experiences concerning the clinical and treatment aspects of myopia in children. The survey reveals several key insights into current practice patterns among Paediatric Ophthalmologists in India regarding paediatric myopia management. The recommended mean age for a child's first eye checkup is 3 years, underscoring the importance of early detection. Refractive error thresholds for prescribing spectacles are set at 3.0 D for infants, 2.0 D for preschool children, and 1.0 D for school-going children older than 3 years. There is a growing trend in using 0.01% Atropine eye drops for myopia management, with a mean prescription age of 4.83 years. Notably, 80.11% of respondents prioritize documenting myopia progression regardless of the child's age. Orthokeratology and Peripheral Defocus spectacle lenses are gaining recognition, and lifestyle modifications such as increasing outdoor activities and reducing near activities are widely acknowledged as effective. While most respondents do not use progressive lenses for myopia, there is significant emphasis on axial length measurements and considering the lag of accommodation. Additionally, under-correction of myopia is favored by a notable proportion of practitioners. These findings indicate a shift towards early intervention and evidence-based strategies in myopia control. The survey highlights a shift towards early intervention and evidence-based myopia control strategies among practitioners. There is, however, room for improvement in standardizing approaches and considering additional factors like axial length and lag of accommodation. Collaborative efforts among policymakers, health regulatory bodies, and industry stakeholders are essential to enhance the accessibility and affordability of myopia control treatments and address the growing health burden associated with paediatric myopia.

The role of peripheral retinal defocus in myopia progression

The increasing incidence of myopia has become a global public health concern. Exploring the mechanisms underlying the onset and progression of myopia is crucial for prevention and control. This paper reviews the role of peripheral retinal defocus mechanisms in the development of myopia, with particular emphasis on the interaction between accommodation lag and peripheral retinal defocus, as well as the impact of optical intervention on myopia control effectiveness. In recent years, researchers have developed various optical tools for myopia prevention and control based on the peripheral retinal defocus theory, such as peripheral defocus spectacle lenses, orthokeratology lenses, and peripheral defocus soft contact lenses. This paper aims to provide clinicians with the latest research findings to deepen their understanding of the mechanisms involved in myopia development and to guide the future development and clinical application of myopia prevention and control products.

Accommodative response and visual fatigue following a non-congruent visual task in non-asthenopic and asthenopic individuals.

Asthenopia is related to near vision activities or visual tasks that dissociate accommodation from vergence. Since the results of previous studies using objective measures to diagnose asthenopia are inconsistent, this study compared optometric tests and objective metrics of accommodation in non-asthenopic and asthenopic young adults before and after a visual fatigue task. The accommodative response was recorded objectively for 6 min at a 3.33 D accommodative demand using an autorefractor, before and after a 5-min non-congruent visual task. Accommodation was disassociated from vergence with a ±2.00 D accommodative flipper while reading at the same distance. Optometric tests and subjective evaluations of asthenopia were performed before and after the task. Twenty-six non-presbyopic adults (23.15 ± 2.56 years) were included and identified as asthenopic (n = 14) or non-asthenopic (n = 12) based on their score on the Computer Vision Syndrome Questionnaire. A mixed ANOVA found no significant difference between the groups for objective (accommodative response) or subjective metrics (feeling of fatigue, optometric tests), although all participants reported greater visual fatigue after the task. A significant effect of time (before and after the non-congruent task) was identified for the overall sample for mean accommodative lag (+0.10 D, p = 0.01), subjective visual fatigue (+1.18, p < 0.01), negative relative accommodation (-0.20 D, p = 0.02) and near negative fusional reserve (blur: +2.46Δ, p < 0.01; break: +1.89Δ, p < 0.01; recovery: +3.34Δ, p = 0.02). The task-induced asthenopia, measured both objectively and subjectively, was accompanied by a change in accommodative lag, greater visual fatigue and a decrease in negative relative accommodation. Conversely, near negative fusional reserves seem to adapt to the task. No significant differences were found between the two groups with respect to accommodative metrics (objective) or subjective and optometric tests.

Influence of Blood Glycemia Levels in Refraction, Binocular Vision and Accommodation: A Case Report

This case report provides us with insight on how blood glycemia affects refraction, vergence and accommodation in a single diabetic patient. A 21-year-old type I diabetic woman was the subject studied in this report. Refraction, near and far fusional vergence ranges, near point of convergence, monocular accommodative facility, amplitude of accommodation, lag of accommodation, and near and far phoria, were measured before and after controlled caloric intake and insulin injection. Measurements were taken a total of 10 times, once a week for 10 consecutive weeks. Blood glycemia levels were provided by a measuring device that was attached to the patient’s body at all times. Statistically significant differences were found in the glucose levels before and after lunch, p = 0.041, sphere refraction of the right eye, p = 0.016, but not in the left eye, p = 0.051. Accommodative facility in both right and left eyes, p = 0.019, p = 0.028, respectively, and amplitude of accommodation, p = 0.016, p = 0.019, right and left eyes, respectively were statistically different before and after insulin injection. In a 21-year-old subject with type I diabetes, a diminution in blood glucose levels influences refractive myopic state, and is associated with a decrease in accommodative facility and in amplitude of accommodation.

Baseline Accommodation and Binocular Vision Measures in Malay Schoolchildren Enrolled in the Myopia Control Study Using Spectacle Lenses in Kuala Lumpur.

Myopia control lenses have been shown to modify visual function; however, it is arguable if these changes are short-term or long-term. We investigated the changes in accommodative behaviour and binocular vision functions of Malay myopic children who participated in a myopia control trial utilising spectacle lenses (n = 40). This article presents baseline accommodation and binocular vision measurements. The mean (± SD) age, spherical equivalent measured by cycloplegic autorefraction, and axial length (AL) for the right eyes were 10.00 ± 1.47 years, -3.02 ± 1.20 D, and 24.42 ± 0.93 mm, respectively. All participants had good distance and near visual acuities with high-contrast charts (100%), which were significantly better than low-contrast charts (10%) (p < 0.001). The mean (± SD) accommodative lag at baseline was 1.14 ± 0.35 D, while monocular and binocular accommodative amplitudes were 15.35 ± 2.07 D and 16.82 ± 2.27 D, respectively. Malay schoolchildren in this study were more esophoric at near compared to distance, with an accommodative-convergence over accommodation (AC/A) ratio of 5.64 ± 0.66 ∆/D. A higher degree of myopia was found to be associated with a longer AL (r = -0.49, p < 0.05) and higher esophoria at near (r = -0.46, p < 0.05). These baseline measures are consistent with data from other studies showing that myopic children have a high accommodative lag, an elevated AC/A ratio, a longer AL, and are more esophoric at near. The measures reported herein will serve as a basis for examining changes that occur within 12 months of wearing myopia control spectacle lenses.

Objective and subjective assessment of accommodative insufficiency.

A variety of subjective and objective procedures are available to measure the amplitude of accommodation. However, it is unclear whether the standard criterion of Hofstetter's minimum minus 2 D can be used to diagnose accommodative insufficiency with each of these techniques. The use of objective dynamic retinoscopy and three subjective techniques to diagnosis accommodative insufficiency was examined. A total of 632 subjects between 8 and 19 years of age were enrolled. Accommodative lag, monocular accommodative facility, and subjective (push-up, modified push-down, and minus lens) and objective (dynamic retinoscopy) amplitude of accommodation were quantified. Accommodative insufficiency was diagnosed based on Hofstetter's minimum minus 2 D for each subjective method, as well as adding an additional subjective criterion (either accommodative lag exceeding 0.75 D or monocular accommodative facility falling below the age-expected norms). The prevalence of accommodative insufficiency was lowest and highest with the push-up (7.9 and 1%) and dynamic retinoscopy (94 and 12%) procedures when measured without and with the additional subjective criteria, respectively. Comparing the validity of dynamic retinoscopy against the traditional criterion, moderate to low sensitivity and high specificity were found. However, adding the additional subjective criteria improved the findings with moderate to high sensitivity and high specificity. Using a cutoff for dynamic retinoscopy of 7.50 D showed moderate diagnostic accuracy based on likelihood ratios. It is clear that a revised definition of accommodative insufficiency is required, which must include the method of assessing accommodation. The various objective and subjective methods for quantifying the amplitude of accommodation are not interchangeable, and subjective assessment does not provide a valid measure of the accommodative response.

Comparing the impact of three-dimensional digital visualization technology versus traditional microscopy on microsurgeons in microsurgery: a prospective self-controlled study.

Emerging three-dimensional digital visualization technology (DVT) provides more advantages than traditional microscopy in microsurgery; however, its impact on microsurgeons' visual and nervous systems and delicate microsurgery is still unclear, which hinders the wider implementation of DVT in digital visualization for microsurgery. Forty-two microsurgeons from the Zhongshan Ophthalmic Center were enrolled in this prospective self-controlled study. Each microsurgeon consecutively performed 30min conjunctival sutures using a three-dimensional digital display and a microscope, respectively. Visual function, autonomic nerve activity, and subjective symptoms were evaluated before and immediately after the operation. Visual functions, including accommodative lag, accommodative amplitude, near point of convergence and contrast sensitivity function (CSF), were measured by an expert optometrist. Heart rate variability was recorded by a wearable device for monitoring autonomic nervous activity. Subjective symptoms were evaluated by questionnaires. Microsurgical performance was assessed by the video-based Objective Structured Assessment of Technical Skill (OSATS) tool. Accommodative lag decreased from 0.63 (0.18) diopters (D) to 0.55 (0.16) D ( P =0.014), area under the log contrast sensitivity function increased from 1.49 (0.15) to 1.52 (0.14) ( P =0.037), and heart rate variability decreased from 36.00 (13.54) milliseconds (ms) to 32.26 (12.35) ms ( P =0.004) after using the DVT, but the changes showed no differences compared to traditional microscopy ( P >0.05). No statistical significance was observed for global OSATS scores between the two rounds of operations [mean difference, 0.05 (95% CI: -1.17 to 1.08) points; P =0.95]. Subjective symptoms were quite mild after using both techniques. The impact of DVT-based procedures on microsurgeons includes enhanced accommodation and sympathetic activity, but the changes and surgical performance are not significantly different from those of microscopy-based microsurgery. Our findings indicate that short-term use of DVT is reliable for microsurgery and the long-term effect of using DVT deserve more consideration.

Poster Session II: The impact of eye's longitudinal chromatic aberration on visual acuity and accommodation response.

Chromatic composition of displays might affect vision and accommodation,possibly influencing myopia development.We investigated differences in visual acuity(VA) and accommodative lag(AccL) for steady accommodative demands (up to 5D,1D steps) with visual stimuli illuminated by monochromatic wavelengths (mono-λ 480,555&630nm,3nm bandwidth) and white light (WL).Data was obtained on 3 young emmetrope using an Adaptive Optics system with a supercontinuum laser,a DMD for stimuli,and a optunable lens to change vergence.Best focus for far was set at 555nm.VA was measured using QUEST(tumbling E).AccL was obtained from the peak shift of through-focus Visual Strehl,calculated from HS aberrometry.All subjects showed myopic shifts in blue consistent with longitudinal chromatic aberration.However,the response to wavelength differed across subjects.S#1 showed a sustained VA across distances(average VA standard deviation 0.054,-0.005logMAR),low AccL(slope:0.3 D/D) and systematic SA negative shift (slope:-0.04um/D),similar across mono-λ and WL.S#2 showed a more sustained VA,lower AccL and higher SA change in blue (0.09logMAR std,0.3D/D,-0.02um/D) than in WL(0.14logMAR std,0.52D/D,-0.013um/D).S#3 showed a steeper decrease in VA at near and higher AccL for mono-λ(0.218logMAR std,0.78D/D,on average)than in WL(0.05logMAR std,0.38D/D).Different subjects use chromatic cues in different ways to accommodate,likely affected by the interplay of chromatic blur,depth-of-focus and defocus sign perception.

Temporal effects of an original myopia song on school children’s myopia and awareness: a 3-year prospective study

ABSTRACT Clinical Relevance Raising children’s myopia prevention awareness and behaviour tends to exhibits a protective effect against myopia among schoolchildren. Background To investigate the effect of an original myopia song in raising school children’s awareness of healthier eye use behaviour and on myopia prevention. Methods In this prospective randomised control study, two groups of students from one primary schools in Jiangxi, China, were enrolled and monitored from grade 3 to grade 6 (2016–2019). The primary outcome was the change in axial length (AL) after the intervention. Secondary outcomes included changes in spherical equivalent refraction (SER), near work and outdoor time, corrected near and distant visual acuity, visual discomfort score (VDS) and accommodative lag. Results Four hundred students (193 females, 48.25%) aged 9.3 (range 8–10) years with emmetropia to moderate myopia were enrolled. Children in the myopia song group had a significantly shorter AL and less myopic refractive change than those in the control group (p = 0.04 and 0.02, respectively). Compared with the control group, children in the myopia song group spent less time on near work and more time outdoors (p = 0.04 and 0.04, respectively). At the final follow-up, the proportion of children with myopia was significantly lower in the myopia song group (30.5%) than in the control group (41%) (p = 0.03). No significant differences were found for the secondary outcomes, including corrected near and distant visual acuity, VDS and accommodative lag. Conclusions An original myopia song performed twice daily in primary schools appeared to have a modest effect on myopia control among school-aged children by changing their lifestyles in the long term.

How Do Most Young Moderate Hyperopes Avoid Strabismus?

Uncorrected hyperopic children must overcome an apparent conflict between accommodation and vergence demands to focus and align their retinal images. This study tested hypotheses about simultaneous accommodation and vergence performance of young hyperopes to gain insight into ocular motor strategies used to maintain eye alignment. Simultaneous eccentric photorefraction and Purkinje image tracking were used to assess accommodative and vergence responses of 26 adult emmetropes (AE) and 94 children (0-13 years) viewing cartoons. Children were habitually uncorrected (CU) (spherical equivalent refractive error [SE] -0.5 to +4 D), corrected and aligned (CCA), or corrected with a history of refractive esotropia (CCS). Accommodative and vergence accuracy, dissociated heterophoria, and vergence/accommodation ratios in the absence of retinal disparity cues were measured for 33- and 80-cm viewing distances. In binocular viewing, median accommodative lags for 33 cm were 1.0 D (AE), 1.33 D (CU), 1.25 D (CCA), and 1.0 D (CCS). Median exophorias at 80 and 33 cm were 1.2 and 4.5 pd (AE), 0.8 and 2.5 pd (CU), and 0 and 1.2 pd (CCA), respectively. Without disparity cues, most response vergence/accommodation ratios were between 1 and 2 meter angle/D (∼5-10 pd/D) (69% of AE, 44% of CU, 60% of CCA, and 50% of CCS). Despite apparent conflict in motor coupling, uncorrected hyperopes were typically exophoric and achieved adultlike accuracy of both vergence and accommodation simultaneously, indicating ability to compensate for conflicting demands rather than bias to accurate vergence while tolerating inaccurate accommodation. Large lags and esophoria are therefore atypical. This analysis provides normative guidelines for clinicians and a deeper mechanistic understanding of how hyperopes avoid strabismus.

Immediate Effects of Vergence Exercises Using Automatic Dual Rotational Risley Prisms on Accommodative Lag and Facility.

This study evaluated novel automatic dual rotational Risley prisms (ADRRPs) as a vergence exercise tool for patients with myopia to improve accommodative lag and accommodative facility. Participants with myopia aged 20-24years were recruited. After vergence exercises with prisms (treatment group) or plano lenses (control group) using ADRRPs for 10min, measurements were taken using an open-field autorefractor (Grand Seiko WAM-5500) at viewing distances of 0.4m and 6.0m. We measured accommodative facility using a ± 2.00D accommodative flipper. A total of 56 participants (treatment group, 39; control group, 17) performed vergence exercises using ADRRPs. Participants in the treatment group showed improvements in accommodative lag at a 0.4m viewing distance, with measurements of 0.57D (right eye; OD) and 0.53D (left eye; OS) and 0.21D (OD) and 0.27D (OS) before and after the exercises, respectively (p < 0.001). Over-refractions using an open-field autorefractor with spherical equivalent contact lenses at a 6.0m viewing distance were - 0.01 ± 0.30D (OD) and 0.03 ± 0.34D (OS) and 0.15 ± 0.32D (OD) and 0.19 ± 0.28D (OS) before and after the exercises, respectively (difference + 0.16D; p < 0.001). Accommodative facility values before and after exercises were 14.88 ± 3.36 and 15.59 ± 3.60cpm, respectively (p < 0.01). No significant differences in accommodative lag, relaxation, and accommodative facility before and after exercise were observed in the control group. Using ADRRPs in vergence exercises can improve accommodative lag, accommodative facility, and accommodative relaxation in adults with myopia. Further research to evaluate persistent and long-term effects is needed.

Influence of a long-distance optical imaging workbench on accommodation and choroidal response in myopic children

ABSTRACT Clinical relevance Optical approaches to modulating near work may be beneficial in arresting the progression of myopia Background To explore whether a long-distance optical image workbench (LOIW) can replace traditional near-distance reading and has beneficial influences on accommodation and choroidal parameters. Methods This self-control study included two sessions. In session 1, an open-field autorefractor measured sustained accommodative response and pupil diameter when participants viewed virtual images from 3.42 m away through LOIW with + 0.50 D over-correction lenses (3.42 m/+0.50 D), LOIW with full-correction lenses (3.42 m/FC), or the visual target at a given distance of 0.33 m with + 0.50 D over-correction lenses (0.33 m/+0.50 D), with full-correction lenses (0.33 m/FC). In session 2, swept-source optical coherence tomography angiography assessed subfoveal choroidal thickness (SFChT), choroidal volume (CV), and choriocapillaris flow void percentage (FV%) at baseline and before and after reading via LOIW with + 0.50 D over-correction lenses (Far/+0.50 D) or in habitual near distance with full-correction (Near/FC) for a sustained 30-min period. Results Thirty-five myopic (mean spherical equivalent refraction: −1.11 ± 0.78 D) children (median [range] age: 8.36 [8–10] years) were analysed. Children viewing virtual images in 3.42 m/+0.50 D exhibited mild-degree accommodative leads (−0.54 ± 0.17 D), much smaller pupil diameter (3.39 ± 0.63 mm) and microfluctuations (0.13 ± 0.04 D); accommodative lags (0.88 ± 0.04 D), larger pupil diameter (5.05 ± 0.75 mm) and microfluctuations (0.88 ± 0.16 D) were observed in 0.33 m/+0.50 D, and the microfluctuations were unstable (F = 2.185, p = 0.038). Compared with baseline data, SFChT, CV, and FV% changed by 13.40 ± 4.71 μm, 0.26 ± 0.21 mm3, and − 0.14%±3.66% in Far/+0.50 D, respectively, while changes under Near/FC were − 10.19 ± 7.48 μm, −0.15 ± 0.22 mm3 and 1.95%±2.92%, respectively. All changes differed significantly between these two conditions (all p < 0.001). Conclusion The long-distance working mode may exert beneficial effects on accommodative and choroidal parameters in myopic children compared with traditional near work.

Accommodation in Children after 4.7 Years of Multifocal Contact Lens Wear in the BLINK Study Randomized Clinical Trial.

When worn for myopia control in children, soft multifocal contact lenses with a +2.50 D add reduced the accommodative response over a 3-year period, but wearing them for more than 4 years did not affect accommodative amplitudes, lag, or facility. This study aimed to compare the accommodative response to a 3D stimulus between single-vision, +1.50-D add, and +2.50-D add multifocal contact lens wearers during 3 years of contact lens wear and then to compare accommodative amplitude, lag, and facility between the three groups after an average of 4.7 years of wear. Bifocal Lenses In Nearsighted Kids study participants aged 7 to 11 years old were randomly assigned to wear single-vision, +1.50-D add, or +2.50-D add soft contact lenses (CooperVision, Pleasanton, CA). The accommodative response to a 3D stimulus was measured at baseline and annually for 3 years. After 4.7 years, we measured objective accommodative amplitudes, lead/lag, and binocular facility with ±2.00-D flippers. We compared the three accommodative measures using multivariate analysis of variance (MANOVA), adjusting for clinic site, sex, and age group (7 to 9 or 10 to 11 years). The +2.50-D add contact lens wearers exhibited lower accommodative response than the single-vision contact lens wearers for 3 years, but the +1.50-D add contact lens wearers exhibited only lower accommodative response than did the single-vision contact lens wearers for 2 years. After adjustment for clinic site, sex, and age group, there were no statistically significant or clinically meaningful differences between the three treatment groups for accommodative amplitude (MANOVA, P = .49), accommodative lag (MANOVA, P = .41), or accommodative facility (MANOVA, P = .87) after an average of 4.7 years of contact lens wear. Almost 5 years of multifocal contact lens wear did not affect the accommodative amplitude, lag, or facility of children.

Evidence of the Amplitude of Accommodation of School-Going Children in the 21st Century.

The study sought to compare the normative amplitude of accommodation (AoA) in school-going children from studies in the 21st century, based on pooled estimates from meta-analyses, to assess their agreement to Hofstetter's average formula. A PRISMA checklist was used to conduct the review. PubMed, EBSCOHOST and Medline electronic databases were employed, and hand searching resulting in 259 studies up to July 2021. After title and abstract screening, 12 studies underwent full-text screening, resulting in five studies for data extraction. The pooled effect size was determined using meta-analyses for sub-groups by age. A one-sample t-test was used to compare the pool-effect size estimates (monocular) to the expected AoA from Hofstetter's average formula. The comparison of pool estimates of AoA with the expected Hofstetter's average formula for the age sub-groups showed significant mean differences for: six-year olds: mean difference of -3.4 D (95% CI: -5.85; -1.04; p = 0.025); nine-year olds: mean difference of -4.1D (95% CI: -7.95; -0.20; p = 0.043); ten-year olds: mean difference of -4.6D (95% CI: -8.57; -0.54; p = 0.035) and 11-year olds: mean difference of -5.2 D (95% CI: -8.06; -2.40; p = 0.005). According to the quality assessment tool used, overall, the body of evidence was of good quality. Hofstetter's prediction of normative amplitude of accommodation today may over-estimate for children aged six, nine, 10 and 11. The observed under-accommodation estimates from these comparisons may warrant consideration in assessing for a larger lag of accommodation in these age groups with myopia or pre-myopia, as part of the surveillance for progression.

Myopia Control Dose Delivered to Treated Eyes by a Dual-focus Myopia-control Contact Lens.

This study examined the optical impact of a DF contact lens during near viewing in a sample of habitual DF lens wearing children. Seventeen myopic children aged 14 to 18 years who had completed 3 or 6 years of treatment with a DF contact lens (MiSight 1 Day; CooperVision, Inc., San Ramon, CA) were recruited and fit bilaterally with the DF and a single-vision (Proclear 1 Day; CooperVision, Inc.) contact lens. Right eye wavefronts were measured using a pyramidal aberrometer (Osiris; CSO, Florence, Italy) while children accommodated binocularly to high-contrast letter stimuli at five target vergences. Wavefront error data were used to compute pupil maps of refractive state. During near viewing, children wearing single-vision lenses accommodated on average to achieve approximate focus in the pupil center but, because of combined accommodative lag and negative spherical aberration, experienced up to 2.00 D of hyperopic defocus in the pupil margins. With DF lenses, children accommodated similarly achieving approximate focus in the pupil center. When viewing three near distances (0.48, 0.31, and 0.23 m), the added +2.00 D within the DF lens treatment optics shifted the mean defocus from +0.75 to -1.00 D. The DF lens reduced the percentage of hyperopic defocus (≥+0.75 D) in the retinal image from 52 to 25% over these target distances, leading to an increase in myopic defocus (≤-0.50 D) from 17 to 42%. The DF contact lens did not alter the accommodative behavior of children. The treatment optics introduced myopic defocus and decreased the amount of hyperopically defocused light in the retinal image.

Prediction of spherical equivalent difference before and after cycloplegia in school-age children with machine learning algorithms.

To predict the need for cycloplegic assessment, as well as refractive state under cycloplegia, based on non-cycloplegic ocular parameters in school-age children. Random cluster sampling. The cross-sectional study was conducted from December 2018 to January 2019. Random cluster sampling was used to select 2,467 students aged 6-18 years. All participants were from primary school, middle school and high school. Visual acuity, optical biometry, intraocular pressure, accommodation lag, gaze deviation in primary position, non-cycloplegic and cycloplegic autorefraction were conducted. A binary classification model and a three-way classification model were established to predict the necessity of cycloplegia and the refractive status, respectively. A regression model was also developed to predict the refractive error using machine learning algorithms. The accuracy of the model recognizing requirement of cycloplegia was 68.5-77.0% and the AUC was 0.762-0.833. The model for prediction of SE had performances of R^2 0.889-0.927, MSE 0.250-0.380, MAE 0.372-0.436 and r 0.943-0.963. As the prediction of refractive error status, the accuracy and F1 score was 80.3-81.7% and 0.757-0.775, respectively. There was no statistical difference between the distribution of refractive status predicted by the machine learning models and the one obtained under cycloplegic conditions in school-age students. Based on big data acquisition and machine learning techniques, the difference before and after cycloplegia can be effectively predicted in school-age children. This study provides a theoretical basis and supporting evidence for the epidemiological study of myopia and the accurate analysis of vision screening data and optometry services.

Comparison of the influence of alcohol and cannabis on the dynamics of the accommodative response.

To assess and compare the changes produced by the two most commonly used substances, alcohol and cannabis, on accommodation dynamics. A total of 38 young participants (19 females) were enrolled in the study. They were assigned to two groups: a cannabis group (N = 19) and an alcohol group. Participants in the cannabis group underwent two randomized sessions: a baseline session and a session after smoking a cigarette. Participants in the alcohol group underwent three randomized sessions: a baseline session, a session after the intake of 300ml of red wine (Alcohol 1), and other after the ingestion of 450ml of wine (Alcohol 2). For the accommodation assessment, the open-field autorefractor WAM-5500 was used. The decrease of the mean velocity of the accommodative response produced by Alcohol 2 condition was significantly greater than that observed for Alcohol 1 and Cannabis (p = 0.046). The direction of the accommodation (near-distance and distance-near) had no effect on the deterioration of the accommodation dynamics following substance use. The target distance had a significant effect on the decrease of the mean velocity following substance use (p = 0.002). The decrease of the amplitude of the accommodative response was associated with a decrease of the peak velocity (p = 0.004) and the increase of the accommodative lag (p < 0.001). A moderate-high dose of alcohol impairs accommodation dynamics to a greater extent that lower dose of alcohol or smoked cannabis. The deterioration of the accommodation mean speed was higher for a shorter target distance.

Addition of Auricular Acupoint Stimulation to 0.01% Atropine for Myopia: 12-Month Results from a Randomized Trial.

Introduction: A previous 6-month report showed that adjunctive auricular acupoint stimulation (AAS) slowed myopia progression compared with 0.01% atropine (0.01% A) alone. This 12-month report was to determine whether the antimyopic effect of AAS, when added to 0.01% A, continued beyond treatment cessation, and explore the mode of action of AAS from the accommodative response. Design and Interventions: One hundred four children were randomly assigned to either a 0.01% A group or a 0.01% A + AAS group. Participants in the 0.01% A + AAS group received AAS in addition to 0.01% A for 6 months, and then kept using 0.01% A for the following 6 months. Participants in the 0.01% A group only used 0.01% A. The primary outcome was the difference in the mean cycloplegic spherical equivalent refraction (SER) from the baseline to the 12-month visit. Secondary outcomes included axial length (AL) and accommodative lag assessments. Results: The adjusted mean change from baseline to month 12 in the SER was -0.62 D for 0.01% A and -0.46 D for 0.01% A + AAS (difference, 0.16 D; p = 0.01), with a respective mean increase of 0.37 and 0.31 mm in AL (difference, -0.05 mm; p = 0.05). For the 5D near target, there was a reduction in the accommodative lag in children receiving add-on AAS relative to 0.01% A alone at 1 and 6 months (both p = 0.002). Conclusions: AAS treatment produced additional benefits >0.01% A in slowing myopia progression over the 12-month period, where the efficacy was sustained after the cessation of AAS. An effect of add-on AAS on reducing accommodative lag in response to 5D stimulus was found, but its role in mediating therapeutic response remained unclear. Chinese Clinical Trial Registry, ChiCTR1900021316.