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Twenty-four young adults with myopia in both eyes and no anisometropia participated in this study. Observers were instructed to read one A4-sized page of Chinese text at different levels of illuminance and text contrast, while their reading distance, head tilt angle and reading speed were recorded using an electromagnetic motion tracking system. Four illuminances (3, 30, 300 and 600 lx) and two text contrast levels (90% and 45%) were tested in randomised order. Observers tended to shorten their reading distance and increase their head tilt angle when reading at low illuminance. In addition, their reading speed was markedly slower at low illuminance and low contrast. These effects were found for both text contrast conditions but were greater at low contrast. Illuminance and text contrast play a critical role in myope’s reading behaviour. An illuminance of 300 lx or more with high-contrast text allows for good reading posture and rapid reading of Chinese text.

Purpose Spectacle lenses containing multiple small peripheral elements have been developed for myopia control in children. It is important that their effect on vision be quantified by (i) fixation through the peripheral portion, thereby using foveal vision and (ii) by fixation through the central portion and presentation of peripheral targets. Methods The above approaches were used in five studies to evaluate two novel spectacle lens designs: spectacle lenses with Highly Aspherical Lenslets (HAL) and Slightly Aspherical Lenslets (SAL). A single vision lens served as a control. Visually normal adults participated in each study. The first two studies had subjects fixate through the periphery of the lenses. High and low (10%) contrast visual acuity was measured with the Freiburg Vision Test and reading speed for high and low contrast words measured with a sentence generator. The other three studies assessed peripheral vision while subjects fixated through the central portion of the lens. Peripheral contrast sensitivity was measured using two cycles per degree drifting Gabor stimuli. Peripheral motion perception was further evaluated using random dot stimuli. Finally, attention was measured using an established test of useful field of view with three levels of complexity. Results The periphery of the HAL lens significantly reduced low contrast visual acuity, but not high contrast visual acuity, while the effect of the SAL lens was not significant for either. Neither test lens affected reading speed for high contrast words, but the HAL lens significantly affected performance for low contrast words. Neither test lens affected peripheral motion perception or useful field of view. Conclusions Low contrast visual acuity and reading was slightly reduced while high contrast visual acuity was unaffected when fixating through the periphery of the novel lens designs. None of the peripheral measures of vision was affected by the novel lens designs.

This study evaluates the impact of the severity of myopia and the type of visual correction in presbyopia on vision-related quality of life (QOL), using the refractive status and vision profile (RSVP) questionnaire. A total of 149 subjects aged 41–75 years with myopic presbyopia were recruited: 108 had low myopia and 41 had high myopia. The RSVP questionnaire was administered. Rasch analysis was performed on five subscales: perception, expectation, functionality, symptoms, and problems with glasses. Highly myopic subjects had a significantly lower mean QOL score (51.65), compared to low myopes (65.24) (p &lt, 0.001). They also had a significantly lower functionality score with glasses (49.38), compared to low myopes (57.00) (p = 0.018), and they had a worse functionality score without glasses (29.12), compared to low myopes (36.24) (p = 0.045). Those who wore progressive addition lenses (PAL) in the high-myope group (n = 25) scored significantly better, compared to those who wore single-vision distance (SVD) lenses (n = 14), with perception scores of 61.19 and 46.94, respectively (p = 0.029). Highly myopic presbyopes had worse overall QOL and functionality, both with and without glasses, compared to presbyopes with low myopia. High-myopic PAL users had a better perception outcome than SVD lens wearers. Low-myopic PAL wearers had a better QOL than SVD wearers.

AimsTo evaluate the 1-year efficacy of two new myopia control spectacle lenses with lenslets of different asphericity.MethodsOne hundred seventy schoolchildren aged 8–13 years with myopia of −0.75 D to −4.75 D were randomised to receive spectacle lenses with highly aspherical lenslets (HAL), spectacle lenses with slightly aspherical lenslets (SAL), or single-vision spectacle lenses (SVL). Cycloplegic autorefraction (spherical equivalent refraction (SER)), axial length (AL) and best-corrected visual acuity (BCVA) were measured at baseline and 6-month intervals. Adaptation and compliance questionnaires were administered during all visits.ResultsAfter 1 year, the mean changes in the SER (±SE) and AL (±SE) in the SVL group were −0.81±0.06 D and 0.36±0.02 mm. Compared with SVL, the myopia control efficacy measured using SER was 67% (difference of 0.53 D) for HAL and 41% (difference of 0.33 D) for SAL, and the efficacy measured using AL was 64% (difference of 0.23 mm) for HAL and 31% (difference of 0.11 mm) for SAL (all pConclusionsSpectacle lenses with aspherical lenslets effectively slow myopia progression and axial elongation compared with SVL. Myopia control efficacy increased with lenslet asphericity.Trial registration numberChiCTR1800017683.

This study shows accommodative accuracy and distance accommodation facility in myopic children do not play a role in myopia progression. In 144 subjects, the monocular distance accommodative facility (DAF) and continuous accommodative stimulus–response curves (ASRCs) were measured at the enrolment. Retrospective and prospective refraction with regard to the enrolment visit were obtained from the outpatient database system based on noncycloplegic subjective spherical equivalent refraction (SER). The rate of myopic progression at enrolment was the first derivative of the Gompertz function, which was fitted with each subject's longitudinal refractive error data, including at least four records of SER with an interval of more than 6 months between each visit. A mixed linear model for multilevel repeated-measures data was used to explore the associations between the rate of myopia progression and accommodative parameters. The mean rate of myopia progression at enrolment was -0.61 ± 0.31 D/y with a mean age of 12.27 ± 1.61 years. By adjusting for age and SER, it was shown that the myopic progression rate was not associated with the accommodative lag (F = 0.269, P = 0.604), accommodative lag area (F = 0.086, P = 0.354), slope of ASRC (F = 0.711, P = 0.399), and DAF (F = 0.619, P = 0.432).

Background/aimsTo evaluate the predictive performance of various predictors, including non-cycloplegic refractive error, for risk of myopia onset under pragmatic settings.MethodsThe Wenzhou Medical University Essilor Progression and Onset of Myopia Study is a prospective cohort study of schoolchildren aged 6–10 years from two elementary schools in Wenzhou, China. Non-cycloplegic refraction, ocular biometry and accommodation measurements were performed. Myopia was defined as spherical equivalent (SE) ≤−0.5 diopter (D). ORs using multivariable logistic regression were determined. Area under the curve (AUC) evaluation for predictors was performed.ResultsSchoolchildren who attended both baseline and 2-year follow-up were analysed (N=1022). Of 830 non-myopic children at baseline, the 2-year incidence of myopia was 27.6% (95% CI, 24.2% to 31.3%). Female gender (OR=2.2), more advanced study grades (OR=1.5), less hyperopic SE (OR=11.5 per D), longer axial length (AL; OR=2.3 per mm), worse presenting visual acuity (OR=2.3 per decimal), longer near work time (OR=1.1 per hour/day) and lower magnitude of positive relative accommodation (PRA; OR=1.4 per D) were associated with myopia onset. PRA (AUC=0.66), SE (AUC=0.64) and AL (AUC=0.62) had the highest AUC values. The combination of age, gender, parental myopia, SE, AL and PRA achieved an AUC of 0.74.ConclusionApproximately one in four schoolchildren had myopia onset over a 2-year period. The predictors of myopia onset include lower magnitude of PRA, less hyperopic SE, longer AL and female gender. Of these, non-cycloplegic SE and PRA were the top single predictors, which can facilitate risk profiling for myopia onset.

Purpose The aim was to evaluate the repeatability of dynamic measurement of the accommodative stimulus–response curve (ASRC) at three different dioptric speeds using a modified instrument and its agreement with two other methods. Methods Twenty‐nine adults (23.5 ± 2.0 years) were enrolled in the study. ASRC was measured monocularly using three methods: dynamic and static measurement using a motorised Badal system mounted on an open‐field auto‐refractor (WAM‐5500, Grand Seiko Co., Ltd, Japan) and the minus lens technique. Dynamic measurements were conducted at three dioptric stimulus speeds to simulate continuous stimuli for ASRC (0.25, 0.40 and 0.55 D/s), with three repetitions for each speed. All three types of ASRCs were fitted with third‐degree polynomial equations. The slope and objective accommodative amplitude of the ASRC were analysed. Results The repeatability of objective accommodative amplitude worsened as the speed of the stimuli increased. The repeatability of the slope was best at a speed of 0.40 D/s and worst at 0.55 D/s. The measurement method significantly influenced the objective accommodative amplitude values and slope (both, p 0.05) and the slope was lowest at 0.55 D/s. Conclusion The accommodative stimulus–response curve values are method‐dependent and the significant differences between three methods used to determine the ASRC based on slope and accommodative amplitude indicate that these methods are non‐interchangeable. Using dynamic measurements, accommodative behaviour varies with the speed of dioptric‐change of the stimulus. A speed of 0.40 D/s appears to be the best compromise in terms of time, results and repeatability for dynamic ASRC measurement.

Purpose To discuss guidelines and ethical considerations associated with the development and prescription of treatments intended for myopia control (MC). Methods Critical review of published papers and guidance documents was undertaken, with a view to carefully considering the ethical standards associated with the investigation, development, registration, marketing, prescription, and use of MC treatments. Results The roles and responsibilities of regulatory bodies, manufacturers, academics, eye care practitioners, and patients in the use of MC treatments are explored. Particular attention is given to the ethical considerations for deciding whether to implement a MC strategy and how to implement this within a clinical trial or practice setting. Finally, the responsibilities in marketing, support, and education required to transfer required knowledge and skills to eye care practitioners and academics are discussed. Conclusions Undertaking MC treatment in minors creates an ethical challenge for a wide variety of stakeholders. Regulatory bodies, manufacturers, academics, and clinicians all share an ethical responsibility to ensure that the products used for MC are safe and efficacious and that patients understand the benefits and potential risks of such products. This International Myopia Institute report highlights these ethical challenges and provides stakeholders with recommendations and guidelines in the development, financial support, prescribing, and advertising of such treatments.

PURPOSE To compare personalized near addition values for myopic children that induce a reasonable phoria (Ph) (meeting Sheard's criterion) and induce a null lag of accommodation at near and to evaluate changes in these metrics after lens adaptation. METHODS Fifty-three myopic children participated in this study. Accommodative response, Ph, and fusional amplitudes (FAs) were measured at 33 cm through multiple addition lenses (0D, +1.00D, +1.50D, +2.00D, +2.50D, +3.00D). The adaptation effect on measured parameters was evaluated after 6 min of near work with each addition. The FA/Ph ratios were calculated for each addition and fitted using a rational function to obtain the optimal addition value satisfying Sheard's criterion (FA/Ph ≥ 2). Lag of accommodation change in association with addition value was assessed using linear regressions to obtain the addition values inducing a null lag. RESULTS Lag of accommodation (r = -0.987, p < 0.001) and Ph (r = -0.999, p < 0.001) decreased linearly with addition value. The 6-min adaptation induced a small but significant increase in accommodative lag and an exophoric shift (p < 0.05). Three FA/Ph patterns with respect to addition lenses were observed based on the near Ph: orthophoria/exophoria, low esophoria, and large esophoria. Addition values based on Sheard's criterion (mean ± SD, +2.16 ± 0.79D) were significantly lower than those based on null lag (+2.83 ± 0.44D, t = 19.86, p < 0.001). The FA/Ph ratio was less than 2.0 in 75.5% of subjects with additions determined through null accommodative lag. Additions determined through FA/Ph ≥ 2 induced a lag of accommodation of 0.38 ± 0.42D. CONCLUSIONS Personalized near addition values using Sheard's criterion were lower than those obtained through null lag of accommodation. These values should allow a better binocular balance especially for exophoric children.

Aims To determine the influence of single-vision lenses (SVLs) and progressive addition lenses (PALs) on the near vision posture of myopic children based on their near phoria. Methods Sixty-two myopic children were assigned to wear SVLs followed by PALs. Eighteen children were esophoric (greater than +1), 18 were orthophoric (−1 to 1) and 26 were exophoric (less than −1) at near. Reading distance, head tilt and ocular gaze angles were measured using an electromagnetic system after adaptation to each lens type. Results The lens type did not influence reading distance or head tilt angle (p>0.05 for both), but ocular gaze angle decreased significantly with the PALs (F=9.25, p=0.004). With the PALs, exophoric children exhibited significantly increased head tilt angle (p=0.003) and reduced ocular gaze angle (p=0.004) compared with esophoric children. Near non-exophoric children exhibited similar eye and head postures when wearing SVLs and PALs, whereas exophoric children exhibited reduced ocular gaze angle (t=−3.18, p=0.04) with PALs compared with SVLs. Using PALs for reading, the mean addition power employed by esophoric children was significantly greater than exophoric children (p=0.04). Conclusions The lens type and the near phoria state affected near vision posture. During reading, myopic esophoric children used a lower portion of their PALs compared with exophoric children, resulting in greater addition power. These results may partially explain why myopic children with near esophoria exhibited superior treatment effects in myopia control trials using PALs.

The dependence of spatial frequency on accommodation has been investigated extensively. Recently, differences between myopes and emmetropes with respect to accommodative microfluctuations for high spatial frequency targets have been reported. Considering the diversity of accommodative responses (ARs) to sinusoidal gratings among subjects, this experiment was designed to analyze the contrast dependence of ARs to targets with various spatial frequencies (SFs). Here, we continuously measured ARs, microfluctuations, and pupil diameter while emmetropic and myopic adult subjects fixated on sinusoidal grating targets of various SFs under standard and near-detection threshold contrast conditions. We first evaluated the detection contrast thresholds at six SFs (2–16cpd) using a near-contrast sensitivity function test that simulated the CSV-1000 test with a tablet computer. We found no difference in contrast threshold between emmetropes and myopes. We then measured the dynamic ARs to 24 grating targets: six SFs and four contrasts (standard, detection threshold, subthreshold and suprathreshold) were recorded for 30s. Under standard contrast conditions, we observed a decrease in AR with increasing spatial frequency. Variations in pupil diameter and accommodation were the smallest at 6cpd. Both the ARs and microfluctuations were higher under near-threshold contrast conditions than under standard contrast conditions, and no variations were found across SFs under near-threshold contrast conditions. No differences in ARs or microfluctuations were found between the two refractive groups at any spatial frequency. These findings provided detailed information on accommodative behavior to spatial frequency targets under normal and high-detection demand conditions.

Purpose To investigate near-vision posture in Chinese myopic schoolchildren and compare near-vision posture during different near-vision tasks (i.e., playing video games, reading, and writing). Methods The study investigated 120 myopic children (grades 1 through 6 and aged 6 to 13 years). An electromagnetic motion-tracking system was used for continuous measurements of the working distance and head declination of the subjects while they were playing video games or reading or writing at a desk. The reading and writing documents were adjusted by grade level (i.e., grades 1 to 2, 3 to 4, and 5 to 6). For analysis, the subjects were grouped in two refractive groups according to their median spherical equivalent refractive error (−1.50D). Results The myopic schoolchildren used close working distances for all tasks: 21.3 ± 5.2 cm (video games), 27.2 ± 6.4 cm (reading), and 24.9 ± 5.8 cm (writing). The mean head declinations were 63.5 ± 12.2 deg (video games), 37.1 ± 12.8 deg (reading), and 44.5 ± 14.1 deg (writing). Working distance decreased significantly across time for the reading and writing tasks (p < 0.001). Head declination increased significantly across time only for the reading task (p < 0.001). Grade level significantly influenced working distance, but the difference was not significant when working distance was adjusted by the subject’s size. No differences were observed within the refractive or the accommodative lag groups in terms of the posture data (p > 0.05). Working distance was negatively correlated with head declination (r = −0.53, p < 0.001). Conclusions Close working distances were observed for Chinese myopic schoolchildren. The attention dedicated to each task, the task difficulty, and the page/screen size may affect near working distance and head declination. Handheld video games were associated with the closest working distance, which may be a risk factor for myopia progression, according to previous studies.

Supplemental Digital Content is available in the text, Background: The aim of this study was to describe the design, methods, and baseline characteristics of children enrolled in the Personalized Addition lenses Clinical Trial (PACT). PACT aims to test the myopia control efficacy of progressive addition lenses (PALs) with personalized addition values compared with standard (+2.00 D) addition PALs and single vision lenses (SVLs). Methods: PACT is a randomized, controlled, double-masked clinical trial. Two hundred eleven myopic Chinese children (7–12 years) were enrolled and randomized into 1 of the 3 following groups: personalized addition PALs; +2.00 addition PALs; and SVLs. Personalized addition values were determined based on the highest addition that satisfied Sheard criterion. Axial length and other biometric data were also recorded. Results: At baseline, no differences were found between the right and left eyes for any of the main parameters. The enrolled children were 9.7 ± 1.1 years’ old with cycloplegic autorefraction (right eye [OD]: −2.36 ± 0.64 D), near phoria (1.0 ± 5.0 prism diopter esophoria), lag of accommodation (1.40 ± 0.50 D) and axial length (OD: 24.58 ± 0.74 mm). The personalized addition values ranged from +0.75 to +3.00 (average ± SD: 2.19 ± 0.73 D). Conclusion: PACT is a clinical trial evaluating whether myopia progression in children can be slowed by wearing personalized addition PALs compared with fixed addition PALs and SVLs as measured by cycloplegic autorefraction and axial length. Baseline data were comparable with those of previous myopia control studies in children. Subjects will be followed up every 6 months for 2 years.

Purpose The spatial frequency (SF) characteristics of accommodation in children are not well understood. In this study, we measured accommodative responses to grating targets to investigate the SF dependence of accommodation in children. Methods The effects of SF and contrast on the accommodative system were evaluated in two groups of children, including 22 with emmetropia and 20 with myopia. The contrast detection thresholds at five SFs were measured using a near-contrast sensitivity function test. The accommodative responses to grating targets with low (1.5 cycles per degree [cpd]), medium (6 cpd), and high (18 cpd) SFs were measured with a Grand Seiko WAM-5500 in dynamic mode for 30 seconds under standard and detection threshold contrast conditions. The accommodative lag and accommodative microfluctuations (AMFs) were compared between the two groups. Results Under standard contrast conditions, no significant difference was found in the accommodative lag across SFs (F = 2.03, P = 0.14) or between the two groups (F = 3.57, P = 0.07). The AMFs were lowest at 6 cpd in emmetropia group (F = 6.51, P = 0.003) and in total (F = 10.82, P < 0.001). Children in emmetropia group showed greater AMFs at high SFs under detection threshold contrast conditions than under standard contrast conditions (P < 0.05). Conclusions This study demonstrated that the instability of accommodation was SF dependent in children. The AMFs in children were smallest at the medium SF for standard contrast grating targets. Myopic children are less sensitive to the low-contrast-induced blur for high SFs than emmetropic children. Translational Relevance This study provides a possibility to stabilize accommodative response of children by transforming SF components of fixation targets.

PURPOSE To investigate the effects of different near addition lenses and prisms on accommodative microfluctuations (AMFs) in Chinese early-onset myopic (EOM) and emmetropic (EMM) children. METHODS Twenty-one EMM and 27 EOM children aged between 9 and 14years participated in the study. At near, 23 children were exophoric (exo

PURPOSE. Peripheral hyperopia was hypothesized to stimulate axial elongation. This study describes peripheral refraction and its associations with central refractive error in young Singapore Chinese children.METHODS. Two hundred fifty children aged 40 months or older recruited from the Strabismus, Amblyopia, and Refractive Error in Young Singapore Children study were included in this analysis. Peripheral refraction was measured after pupil dilation using an infrared autorefractor. A total of five measurements were captured: central visual axis and 15 and 30 eccentricities in the nasal and temporal visual fields.RESULTS. The mean age of the participants recruited was 83 +/- 36 months. There were 37 children with high and moderate myopia ( 1.0 D; 18.8%). Compared with the central axis, children with high and moderate myopia had relative hyperopia at all peripheral eccentricities (P < 0.001), whereas children with low myopia had relative hyperopia only at the temporal and nasal 30 degrees (P < 0.001), but not at the nasal and temporal 15 degrees. Children with emmetropia and hyperopia had peripheral relative myopia at all eccentricities (P < 0.001). A significant correlation between the nasal and temporal refractive error at 30 degrees was noted (Spearson's correlation coefficient = 0.85, P < 0.001).CONCLUSIONS. Young myopic Singapore Chinese children had relative hyperopia in the periphery. This study substantiates previous studies in older children and in Caucasian subjects. (Invest Ophthalmol Vis Sci. 2011; 52:1181-1190) DOI:10.1167/iovs.10-5601

Objective To determine whether bifocal and prismatic bifocal spectacles could control myopia in children with high rates of myopic progression. Methods This was a randomized controlled clinical trial. One hundred thirty-five (73 girls and 62 boys) myopic Chinese Canadian children (myopia of ≥1.00 diopters [D]) with myopic progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments: (1) single-vision lenses (n = 41), (2) +1.50-D executive bifocals (n = 48), or (3) +1.50-D executive bifocals with a 3–prism diopters base-in prism in the near segment of each lens (n = 46). Main Outcome Measures Myopic progression measured by an automated refractor under cycloplegia and increase in axial length (secondary) measured by ultrasonography at 6-month intervals for 24 months. Only the data of the right eye were used. Results Of the 135 children (mean age, 10.29 years [SE, 0.15 years]; mean visual acuity, −3.08 D [SE, 0.10 D]), 131 (97%) completed the trial after 24 months. Myopic progression averaged −1.55 D (SE, 0.12 D) for those who wore single-vision lenses, −0.96 D (SE, 0.09 D) for those who wore bifocals, and −0.70 D (SE, 0.10 D) for those who wore prismatic bifocals. Axial length increased an average of 0.62 mm (SE, 0.04 mm), 0.41 mm (SE, 0.04 mm), and 0.41 mm (SE, 0.05 mm), respectively. The treatment effect of bifocals (0.59 D) and prismatic bifocals (0.85 D) was significant (P Conclusions Bifocal lenses can moderately slow myopic progression in children with high rates of progression after 24 months. Applications to Clinical Practice Bifocal spectacles may be considered for slowing myopic progression in children with an annual progression rate of at least 0.50 D. Trial Registration clinicaltrials.gov Identifier:NCT00787579

International audience; This study investigated how the visual system detects a surface deviation from planar, induced by, crossed or uncrossed, horizontal disparities continuously increasing with eccentricity. Binocular disparities increased linearly and concentrically, between two given eccentricities. The thresholds of deformation detection were gathered using a method in which observers halted a dynamic stimulus. The thresholds were substantially higher than those measured by the control experiment using a method of constant stimuli. Results, using the adjustment method, highlighted lower discrimination thresholds for uncrossed disparities than for crossed disparities. For all the directions of disparity, thresholds varied similarly as a function of eccentricity, however two observations could be pointed out: thresholds of peripheral start depended on disparity gradient and starting eccentricity; fovea start thresholds did not depend on disparity gradient alone. Data suggests that, in peripheral field, the visual system was more sensitive to uncrossed disparities than crossed disparities, relative to the frontoparallel plane. According to a verbal report from observers, the reference used for the perceptive judgment appears not to be the screen plane but rather the peripheral stimulus. Moreover, in the deformation detection of planar surfaces, horizontal disparities processing depends on the eccentric location of the disparities. It could be global for the peripheral locations and could be based more on depth contrast for the central locations.

Myopia is a significant public health problem, making it important to determine whether a bifocal spectacle treatment involving near prism slows myopia progression in children.To determine whether bifocal and prismatic bifocal spectacles control myopia in children with high rates of myopia progression and to assess whether the treatment effect is dependent on the lag of accommodation and/or near phoria status.This 3-year randomized clinical trial was conducted in a private practice. A total of 135 (73 female and 62 male) Chinese-Canadian children (aged 8-13 years; mean [SE] age, 10.29 [0.15] years; mean [SE] myopia, -3.08 [0.10] D) with myopia progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments. A total of 128 (94.8%) completed the trial.Single-vision lenses (control, n = 41), +1.50-D executive bifocals (n = 48), and +1.50-D executive bifocals with 3-Δ base-in prism in the near segment of each lens (n = 46). MAIN OUTCOMES AND MEASURES Myopia progression (primary) measured using an automated refractor following cycloplegia and increase in axial length (secondary) measured using ultrasonography at intervals of 6 months for 36 months. RESULTS Myopia progression over 3 years was an average (SE) of -2.06 (0.13) D for the single-vision lens group, -1.25 (0.10) D for the bifocal group, and -1.01 (0.13) D for the prismatic bifocal group. Axial length increased an average (SE) of 0.82 (0.05) mm, 0.57 (0.07) mm, and 0.54 (0.06) mm, respectively. The treatment effect of bifocals (0.81 D) and prismatic bifocals (1.05 D) was significant (P .001). Both bifocal groups had less axial elongation (0.25 mm and 0.28 mm, respectively) than the single-vision lens group (P .001). For children with high lags of accommodation (≥ 1.01 D), the treatment effect of both bifocals and prismatic bifocals was similar (1.1 D) (P .001). For children with low lags (1.01 D), the treatment effect of prismatic bifocals (0.99 D) was greater than of bifocals (0.50 D) (P = .03). The treatment effect of both bifocals and prismatic bifocals was independent of the near phoria status.Bifocal spectacles can slow myopia progression in children with an annual progression rate of at least 0.50 D after 3 years. These results suggest that prismatic bifocals are more effective for myopic children with low lags of accommodation. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00787579.

The size of sensory fusional and refusional areas of seven observers were measured for three fixation distances and eight retinal eccentricities. Results show that sensory fusion is affected by fixation distance and retinal eccentricity.

PURPOSE. Relative peripheral hyperopia has been associated with central myopia. This study was conducted to determine whether baseline relative peripheral hyperopia is associated with an increased risk of developing myopia or myopia progression in young Singapore Chinese children. METHODS. One hundred eighty-seven children who participated in the Peripheral Refraction in Preschool Children (PREP) Study at baseline underwent a follow-up examination. Autorefraction was performed at five eccentricities with an infrared autorefractor after cycloplegia: central axis and 15° and 30° eccentricities in the nasal and temporal visual fields. The primary outcomes were development of myopia among children who were nonmyopic at baseline, and myopia progression in those who were myopic at baseline. RESULTS. The mean age of the children at baseline was 7.2 ± 3.0 years, and the mean duration of follow-up was 1.26 years. At baseline, 96 children were myopic (mean central spherical equivalent [SE] -2.75 ± 1.72 D) and 91 were nonmyopic (mean central SE 0.76 ± 0.81 D). Baseline relative peripheral hyperopia was not associated with a greater likelihood of becoming myopic or myopia progression. At follow-up, children who remained nonmyopic (n = 24) retained relative peripheral myopia at all eccentricities, whereas those who became myopic (n = 67) developed relative peripheral hyperopia at the nasal (+0.44 ± 0.72 D) and temporal 30° (+0.13 ± 0.74 D). The mean change in central SE was -1.51 ± 0.63 D/y for children who developed myopia, -0.82 ± 0.76 D/y for children who were myopic at baseline, and -1.05 ± 0.80 D/y for all children. CONCLUSIONS. Baseline peripheral refraction did not predict the subsequent onset of myopia or influence the progression of myopia.

Sizes of fusional and refusional areas were measured at various eccentricities between ±12° for a 40 cm fixation distance. It is shown that the size of fusional areas (SFA) may increase or stay quasi-constant with eccentricity, depending on the observer. For all observers, the size of refusional areas is within the limits of SFA and remains quasiconstant with eccentricity.