Objective Quantification and Topographic Dioptric Demand of Near-Work.

Purpose: The assessment of myopigenic environmental risk factors such as near-work relies on subjective data. Although diaries and questionnaires on near-work show correlation to some degree, it remains unknown how they may correspond to ground truth. This is an important consideration because valid estimates of near-work have great utility for understanding the mechanisms by which dioptric demand drives excessive eye-growth, which is not yet entirely understood. To this end, we assessed a novel eye-tracking system to quantify near-work. Method: We compared subjective entries from diaries to objective data on accommodative demand acquired with a three-dimensional eye-tracker in 20 participants. Each test involved approximately one-hour exposure to ecological near-work environments. Furthermore, topographical dioptric demand maps were computed in retinal coordinates. Results: Our study suggests a frequent mismatch between objectively and subjectively labeled data of near-work tasks (concordance 74.6%). Objective and subjective estimates of dioptric demand showed a moderate correlation and were not significantly different (R2 = 0.59, P = .35). Instead, accommodative demand with an agreement between objective and subjective near-work labels showed a high correlation and were significantly different (R2 = 0.79, P = .016). The accumulated topographical dioptric demand of ecological near-work environments did not present myopigenic defocus stimuli to the retina periphery. Thus extreme close-up near-work presented peripheral defocus stimuli that have been proposed to curb excessive eye growth. Conclusions: The proposed objective measurement method may provide improvements over subjective methods for estimating near-work parameters. Translational Relevance: The topographic dioptric demand maps highlight a possible conflict of causal mechanisms of the two myopia models: "excessive near-work" and "peripheral optical defocus."

Corneal Electrolysis for Granular Corneal Dystrophy Type 2 (Avellino Corneal Dystrophy) Exacerbation After LASIK.

PURPOSE: To report two cases in which exacerbation of granular corneal dystrophy type 2 (GCD2; Avellino corneal dystrophy) after laser in situ keratomileusis (LASIK) was successfully removed by corneal electrolysis. METHODS: This study involved a 66-year-old man and a 43-year-old man with GCD2 who had undergone bilateral LASIK for myopia 10 or more years prior to presentation. In both patients, GCD2 corneal opacity gradually developed postoperatively at the LASIK flap interface, thus resulting in a decrease of visual acuity. For treatment, the LASIK flaps in both patients were surgically lifted to directly remove the opacity. Corneal electrolysis was then applied to the back of each LASIK flap and stromal bed. RESULTS: Postoperatively, the ocular symptoms and corneal opacities related to GCD exacerbation disappeared, with improvement of corrected and uncorrected distance visual acuity and almost no change of refractive error. CONCLUSIONS: The findings reveal that corneal electrolysis is safe and effective for treating exacerbations of GCD2 following LASIK when applied to a surgically lifted flap, and that it successfully removes GCD2-related LASIK flap interface opacities with almost no change of refractive error postoperatively. [J Refract Surg. 2023;39(1):61-65.].

Association between whole-grain intake and myopia in chinese children: a cross-sectional epidemiological study.

BACKGROUND: Nutritional status influences the growth and development of the eyes. However, there are few studies on the association between diet, especially whole grains (WG) consumption, and myopia. The study aimed to evaluate the association between WG intake and myopia prevalence among primary school-age children in China. METHODS: This cross-sectional epidemiological study conducted between November 2019 and December 2019 included 586 children, aged 6-12 years, attending primary school in Binhai district, Tianjin, China. Ophthalmologic examinations and optometric cycloplegic refraction measurements were conducted. Information was collected on known risks and protective factors for myopia and the consumption of WGs, vegetables, and fruits. This association between the probability of myopia and the proportion of WG consumption (WG proportion was calculated as the mean intake from WG sources divided by total grain intake), adjusted for protective and risk factors, was analysed using crude and multivariable logistic regression. RESULTS: Among the study participants, 226/586 (38.57%) children had myopia in at least one eye. WG intake was inversely correlated with the prevalence of myopia. Furthermore, in the multivariate analysis, WG intake of > 50% was identified as a protective factor against myopia after subsequent adjustment for children's age, sex, parental myopia, near-work activity, screen time, reading and writing habits, visual fatigue, outdoor time, and classroom light environment (all P < 0.05). CONCLUSION: WG intake (> 50%) was an independent protective factor against myopia. Modifying the form of grains consumed (whole versus refined) could be one of the targets of future public health measures.

Myopia and Its Association with Near Work, Outdoor Time, and Housing Type among Schoolchildren in South India.

SIGNIFICANCE: In this comprehensive assessment of environmental associations with refractive status among schoolchildren in India, outdoor time was the key modifiable risk factor associated with myopia rather than time spent on near work. PURPOSE: This study aimed to investigate the environmental risk factors associated with myopia among adolescent schoolchildren in South India. METHODS: Children in grades 8 to 10 from 11 schools in Tamil Nadu, South India, underwent eye examination and risk factor assessments through a modified version of the Sydney myopia questionnaire. Time spent on near work and outdoors was analyzed after division into three groups based on tertiles. Mixed-effects logistic regression was performed to assess the factors associated with myopia. RESULTS: A total of 3429 children (response rate, 78.4%) provided both questionnaire and refraction data. The mean (standard deviation) age was 14 (0.93) years with an equal distribution of sexes. Myopia was present among 867 children (noncycloplegic spherical equivalent refraction, ≤-0.75 D). Refraction was not associated with near work tertiles ( P = .22), whereas less time outdoors was associated with higher myopic refractions ( P = .01). Refraction shifted toward increased myopia with an increase in the near-work/outdoor time ratio ( P = .005). Children living in apartment housing had a higher prevalence of myopia compared with other types of housing ( P < .001). In multivariate analysis, increased time outdoors was a protective factor against myopia (odds ratio, 0.79; 95% confidence interval, 0.63 to 0.99; P = .04), whereas living in apartment housing (odds ratio, 1.27; 95% confidence interval, 1.04 to 1.55; P = .02) was a significant risk factor. CONCLUSIONS: In this cohort of Indian children, outdoor time, increased near-work/outdoor time ratio, and type of housing were the factors associated with myopia. Policies should target implementing a balance between near-work and outdoor time among children.

Compensation for Vitreous Chamber Elongation in Infancy and Childhood.

SIGNIFICANCE: The ratios of diopters of change in refractive error produced per millimeter of eye elongation (D/mm) are rarely those predicted from geometric optics because of changes in other ocular components. Quantifying this optical compensation in millimeters instead of ratios reveals some important principles about eye growth and refractive error. PURPOSE: The study purpose was to sort total vitreous chamber elongation into millimeters that either contributed (uncompensated) or did not contribute to change in refractive error (compensated). METHODS: Participants were infants in the Berkeley Infant Biometry Study (n = 271, ages 3 months to 6 years) or schoolchildren in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (n = 456 emmetropes and 522 myopes, ages 6 to 14 years). Refractive error was measured using cycloplegic retinoscopy in infants (cyclopentolate 1%) and cycloplegic autorefraction in schoolchildren (tropicamide 1% or combined with cyclopentolate 1%). Axial dimensions were assessed using A-scan ultrasonography. Uncompensated millimeters were estimated from ratios of change in refractive error per millimeter of elongation using Gullstrand eye models. Compensated millimeters were the difference between measured elongation and uncompensated millimeters. RESULTS: Compensated millimeters exceeded uncompensated millimeters in emmetropic children across ages, but uncompensated millimeters exceeded compensated millimeters in myopic children. Compensated millimeters were highest in infancy and decreased with age, reaching less than 0.10 mm per year by age 10 years in both myopic and emmetropic children. There were no statistically significant differences in compensated millimeters between myopic and emmetropic children between ages 8 and 14 years ( P values from .17 to .73). CONCLUSIONS: The ability of the ocular components, primarily crystalline lens, to compensate for vitreous elongation is independent of the higher demands of myopic eye growth. The limited compensation after age 10 years suggests the target for elongation in myopia control needed to arrest myopia progression may be that seen in emmetropes or less.

A systematic review of near work and myopia: measurement, relationships, mechanisms and clinical corollaries.

After decades of investigation, the role of near work in myopia remains unresolved, with some studies reporting no relationship and others finding the opposite. This systematic review is intended to summarize classic and recent literature investigating near work and the onset and progression of myopia, potential mechanisms and pertinent clinical recommendations. The impact of electronic device use is considered. PubMed and Medline were used to find peer-reviewed cross-sectional and longitudinal studies related to near work and myopia from 1980 to July 2020 using the PRISMA checklist. Studies were chosen using the Joanna Briggs Institute checklist, with a focus on studies with a sample size greater than 50. Studies were independently evaluated; conclusions were drawn per these evaluations. Numerous cross-sectional studies found increased odds ratio of myopia with increased near work. While early longitudinal studies failed to find this relationship, more recent longitudinal studies have found a relationship between myopia and near work. Rather than daily duration of near work, interest has increased regarding absolute working distance and duration of continuous near viewing. Several reports have found that shorter working distances (<30 cm) and continuous near-work activity (>30 min) are risk factors for myopia onset and progression. Novel objective continuously measuring rangefinding devices have been developed to better address these questions. The literature is conflicting, likely due to the subjective and variable nature in which near work has been quantified and a paucity of longitudinal studies. We conclude that more precise objective measures of near viewing behaviour are necessary to make definitive conclusions regarding the relationship between myopia and near work. Focus should shift to utilizing objective and continuously measuring instruments to quantify near-work behaviours in children, followed longitudinally, to understand the complex factors related to near work. A better understanding of the roles of absolute working distance, temporal properties, viewing breaks and electronic device use on myopia development and progression will aid in the development of evidence-based clinical recommendations for behavioural modifications to prevent and slow myopia.

Visual Outcomes of Photorefractive Keratectomy Enhancement After Primary LASIK.

PURPOSE: To evaluate the safety, efficacy, and predictability of photorefractive keratectomy (PRK) at least 4 years after primary laser in situ keratomileusis (LASIK) and compare it to the United States Food and Drug Administration (FDA) criteria. METHODS: This retrospective, single-site study compared patients who underwent PRK enhancement from 2014 to 2019 after primary LASIK to those who only underwent primary LASIK without re-treatment from the same time period. Patient demographics and clinical information were compared between the two groups. Visual outcomes and postoperative complications were evaluated in the enhancement group. RESULTS: A total of 374 eyes with PRK enhancement were compared to 472 without re-treatment. Age, sex, surgical eye, and preoperative sphere, and spherical equivalent (SE) were significantly different between the enhancement and control groups (P < .05). At 12 months post-enhancement, 67% had uncorrected distance visual acuity (UDVA) of 20/20 or better, 98% had UDVA of 20/40 or better, and 0.4% of eyes lost at least two lines of corrected distance visual acuity (CDVA). A total of 83% and 98% of eyes were within ±0.50 and ±1.00 diopters of the target, respectively. Post-enhancement complications (n = 66) included dryness (6.1%), epithelial ingrowth (2.7%), and haze (2.7%). CONCLUSIONS: Older age at the time of the primary LASIK, female sex, right surgical eye, and more myopic sphere and SE were risk factors for enhancement. Although PRK enhancements are considered off-label procedures, they produce favorable outcomes at 3 and 12 months postoperatively while meeting FDA benchmarks for safety, efficacy, and predictability. [J Refract Surg. 2022;38(11):733-740.].

The relationship between myopia and near work, time outdoors and socioeconomic status in children and adolescents.

BACKGROUND: To investigate environmental and social risk factors for myopia in children and adolescents in Germany. METHODS: 1437 children aged between 3 and 18 inclusive were examined as part of the LIFE Child study based in Leipzig, Germany. Information about leisure time activities and social status was ascertained by parents and children in a questionnaire. Refractive status was attained by measuring noncycloplegic autorefraction. Myopia was defined as spherical equivalent (SE) ≤ - 0.75 D. Risk factors were identified using multiple logistic regression analysis. RESULTS: In multiple logistic regression analysis, myopia was significantly associated with less frequent outdoor activity ("once a week" vs. "twice a week or more": odds ratio (OR) 4.35, 95% confidence interval (CI) 1.89-9.98, p<0.01) and longer near work sessions (1-2 h vs. < 1 h: OR 1.83, CI 1.10-3.04, p=0.02; > 3 h vs. < 1 h: OR 3.71, CI 1.43-9.61, p<0.01) after adjustment for age, sex and socioeconomic status (SES). Duration of outdoor activity, near work frequency and SES showed no significant association with myopia (p > 0.05). Children with a lower SES were involved in longer periods of outdoor and near work activities but on fewer occasions over the course of the week, although this connection was not significant. CONCLUSION: Myopia is associated with environmental factors. The present findings suggest that daily exposure to sunlight and a restriction of long-duration near work activities might protect against pathological eye growth. Prevention strategies should be implemented for children at all ages.

[Association of beverages intake with myopia among 11-14-year-old Chinese children in 2019-2021].

OBJECTIVE: To describe beverages intake and its association with myopia among 11-14-year-old children in China. METHODS: Multi-stage stratified cluster random sampling was used and children aged 11 to 14 years were selected from 28 cities and rural areas in 14 provinces in China, and a total of 12 397 children were included in this study. Information including demographic characteristics, myopia status, dietary intake, physical activity, screen time, sleep duration were collected from questionnaire survey. RESULTS: During 2019-2021, the prevalence of myopia among children aged 11 to 14 in China was 45.0%. The median beverages intake was 42.7 g/d. Children who did not drink beverages and whose beverages intake was <150 g/d and ≥150 g/d accounted for 42.8%, 44.8% and 48.4%, respectively. Multivariate Logistic regression analysis showed that girls' beverages intake ≥150 g/d was still a risk factor for the prevalence of myopia after controlling for confounding factors such as age, area, physical activity, screen time, sleep duration and intake of sugary food(OR=1.24, 95%CI 1.08-1.42, P<0.05). Among children with myopia, mild myopia, moderate and above myopia accounted for 71.6% and 28.4% among boys and 73.8% and 26.3% among girls, respectively. There was no statistically significant regression between beverages intake and myopia in boys and girls regardless of whether confounding factors were adjusted(P >0.05). CONCLUSION: Children's beverages intake was generally common in China in 2019-2021. Children who consumed higher beverages were more likely to have myopia than that did not consume beverages.

[Relationship between sugary food intake and myopia in 11-14 years old Chinese children in 2019-2021].

OBJECTIVE: To investigate the relationship between the intake of sugary foods and the occurrence and development of myopia in children aged 11-14 in China. METHODS: In the 28 urban and rural survey sites in 14 provinces that implemented the "China Children's Nutrition and Health System Survey and Application for 0-18 Years Old" project, a multi-stage stratified random cluster sampling method was adopted, and finally 12 397 adolescent children aged 11 to 14 were selected in the analysis. Demographic characteristics, myopia information and the intake of sugary food(cakes, preserved fruits, candies, chocolates and ice cream) were collected through questionnaires. Multifactor Logistic regression was used to analyze the relationship between sugary food intake and myopia in children. RESULTS: The median daily intake of sugary foods(cakes, preserved fruits, candies, chocolates and ice cream)of 11-14 year old boys and girls in China was 11.4 g and 11.2 g respectively, 33.9% of boys and 34.2% of girls consumed ≥22 g of sugary food every day. The myopia rates of boys with intakes of <2 g, 2-21 g and ≥22 g were 36.0%, 39.2% and 41.6%, and girls' myopia rates were 45.9%, 51.8% and 55.1%. The result of Logistic regression analysis showed that after controlling for confounding factors such as age, gender, region, weekly high-intensity physical activity time, daily screen time, daily sleep time and daily intake of sugary beverages, compared with boys whose daily intake of sugary food was less than 2 g, the risk of myopia for boys whose daily intake of sugary food reached 2-21 g and ≥22 g was 1.18 and 1.23 times, for girls whose daily intake was less than 2 g, the risk of myopia was 1.27 times and 1.38 times for girls whose intake reached 2-21 g and ≥22 g(P<0.05). No matter whether confounding factors were controlled or not, there was no correlation between the intake of sugary foods and the degree of myopia(P>0.05). CONCLUSION: The consumption of sugary food such as cakes, preserved fruits, candies, chocolates and ice cream among children aged 11 to 14 in China is common, and there is a certain degree of positive correlation with the prevalence of myopia, but no correlation is observed with the degree of myopia.

Fallopia Japonica and Prunella vulgaris inhibit myopia progression by suppressing AKT and NFκB mediated inflammatory reactions.

BACKGROUND: The increased global incidence of myopia requires the establishment of therapeutic approaches. This study aimed to investigate the effect of Fallopia Japonica (FJ) and Prunella vulgaris (PV) extract on myopia caused by monocular form deprivation (MFD). METHODS: We used human retinal pigment epithelial cell to study the molecular mechanisms on how FJ extract (FJE) and PV extract (PVE) lowering the inflammation of the eye. The effect of FJE and PVE in MFD induced hamster model and explore the role of inflammation cytokines in myopia. RESULTS: FJE + PVE reduced IL-6, IL-8, and TNF-α expression in RPE cells. Furthermore, FJE and PVE inhibited inflammation by attenuating the phosphorylation of protein kinase B (AKT), and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) pathway. In addition, we report two resveratrol + ursolic acid compounds from FJ and PV and their inhibitory activities against IL-6, IL-8, and TNF-α expression levels in RPE cells treated with IL-6 and TNF-α. FJE, PVE, and FJE + PVE were applied to MFD hamsters and their axial length was measured after 21 days. The axial length showed statistically significant differences between phosphate-buffered saline- and FJE-, PVE-, and FJE + PVE-treated MFD eyes. FJE + PVE suppressed expressions of IL-6, IL-8, and TNF-α. They also inhibited myopia-related transforming growth factor-beta (TGF)-ß1, matrix metalloproteinase (MMP)-2, and NF-κB expression while increasing type I collagen expression. CONCLUSIONS: Overall, these results suggest that FJE + PVE may have a therapeutic effect on myopia and be used as a potential treatment option.

ANATOMIC AND TOPOGRAPHIC CHANGES OF ANTERIOR SEGMENT STRUCTURES IN EHLERS-DANLOS SYNDROME PATIENTS WITH MYOPIA.

OBJECTIVE: The aim: Determination of anatomical and topographical relationships of the eyeball anterior segment structures to assess possible glaucoma development risk factors in SED patients with myopic refraction. PATIENTS AND METHODS: Materials and methods: Patients, aged from 10 to 34, have been examined since 2009. All the patients have undergone required medic and genetic examination as well as generally accepted ophthalmological one. Ultrasound biomicroscopy (UBM) has been performed using the VuMax II apparatus (Sonomed, USA) with a sensor frequency of 50 MHz. RESULTS: Results: Biomicroscopy found no symptoms such as pigment dispersion on the iris stroma, in the chamber anterior angle, iris transillumination and "Krukenberg's Spindle", which are characteristic for the ultrasound picture in pigment dispersion syndrome. CONCLUSION: Conclusions: 1. Clinical and functional study with the eyeballs mandatory ultrasound biomicroscopy have revealed functional space limitations for the structures of the iridociliary zone in patients with myopic type of eye structure in SED. 2. Detected congenital changes in the anterior segment structures (iridociliary cystic formations and residual mesodermal tissue) can lead to the emergence of intraocular blocks. 3. The research has identified conducive anatomical and topographic changes, which are likely to induce pigment dispersion syndrome or lead to the development of pigmentary glaucoma. 4. In our opinion, the UBM role in the early diagnosing and monitoring patients with SED syndrome is quite significant in terms of assessing the stability or dynamics of the changes received and possible complications. Ultrasound biomicroscopic scanning should be added to the list of necessary early diagnostic examinations to determine the markers and features of structures in SED.

Near work induces myopia in Guinea pigs.

The association between near work activities and myopia has not been clearly established. This study establishes a model for near work myopia (NWM) induced by short viewing distance in guinea pigs with a carefully controlled visual environment, and evaluates the effect of viewing distance in myopia development. Pigmented guinea pigs (3 weeks old) were randomly assigned to 3 groups: near work (NW)-, form-deprivation (FD)-, and -4D hyperopic-defocus (HD)-induced myopia. Animals in NW groups were kept in cylindrical cages with vertical square-wave gratings, providing short- (S, d = 18 cm), middle- (M, d = 44 cm), and long- (L, d = 88 cm) mean viewing distances, all at the same illuminance, during daily treatment for 14 days. Biometric parameters, including refraction, anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD), and axial length (AL), were measured at the beginning and end of 14 days' treatment. Choroidal thickness (ChT) and choroidal blood perfusion (ChBP) were measured by optical coherence tomography (OCT) and OCT-angiography (OCTA), respectively, at the end of treatment. Refraction was shifted towards myopia in the S-cage group, compared with the M- and L-cage groups; refractions in the L-, M- and S-cage groups were 5.19 ± 0.65 D, 4.30 ± 0.64 D, and 0.53 ± 0.61 D, respectively (p < 0.001). VCD and AL in the S-cage group increased in parallel with the myopic shift (L vs M vs S: VCD: 3.15 ± 0.02 mm vs 3.17 ± 0.02 mm vs 3.26 ± 0.02 mm, p < 0.001; AL: 7.99 ± 0.03 mm vs 8.03 ± 0.03 mm vs 8.15 ± 0.02 mm, p = 0.001). In FD and HD eyes, changes similar to those in the S-cage group (near-work group, NW) were seen in refraction (NW vs FD vs HD: 5.36 ± 0.82 D vs -5.78 ± 0.44 D vs -4.96 ± 0.54 D, p = 0.734), ACD, LT, VCD and AL. Also, ChT and ChBP were significantly less in the S-cage group than in the M- and L-cage groups after 14 days' treatment (L vs M vs S: ChT: 74.84 ± 3.27 vs 76.07 ± 3.49 vs 61.95 ± 3.31, P = 0.002; ChBP: 48.32 ± 2.23 vs 48.66 ± 2.30 vs 38.14 ± 2.06, p = 0.002). Rearing in S-cages induced myopia in guinea pigs and correspondingly decreased ChBP and ChT. The present study provides objective evidence that short viewing distance could be a risk factor for myopia, and describes a useful model for studying the underlying mechanisms.

Flap-making patterns and corneal characteristics influence opaque bubble layer occurrence in femtosecond laser-assisted laser in situ keratomileusis.

BACKGROUND: Opaque bubble layer (OBL), which generates from photo-disruptive procedures on the cornea, has been a common phenomenon during femtosecond laser-assisted refractive surgeries and it would potentially impact eye tracking and flap lifting. And we have observed that an updated flap-making pattern could form less OBL clinically than the traditional pattern, which needed further approval. Thus, the purpose of this study is to prove our observation and investigate the possible risk factors related to the occurrence and type of OBL in laser in situ keratomileusis (LASIK) flaps using the Visumax laser system. METHODS: This prospective study included 167 eyes of 86 patients (mean age: 27.5 ± 6.1 years) undergoing bilateral femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for myopia/myopic astigmatism by the same surgeon from April 2020 to August 2020. Preoperative data on refraction, central corneal thickness (CCT), and keratometry as well as intraoperative data were included for analysis. A new flap-making pattern creating an offset between flap-cut and side-cut was adopted to compare with the traditional pattern. The operation video of flap formation was analyzed to identify the existence and type of OBL. The area covered by OBL and the ratio of OBL to flap were calculated using Image J software. RESULTS: Among 167 eyes, 54 eyes (32.3%) developed OBLs, consisting of 31 as hard OBL coexisting with soft OBL, and 23 as soft OBL alone. The OBL incidence was significantly reduced in eyes with the new flap-making pattern compared with the traditional pattern (13.8% vs. 52.5%, P < 0.001). Hard OBLs had larger area ratios than soft OBLs (14.3 ± 8.3% vs. 1.1 ± 1.8%, P < 0.001). Univariate analyses revealed that eyes with more myopia, thicker CCT, and traditional flap-making patterns were more likely to develop OBLs. Multivariate analysis further confirmed that more myopia, thicker CCT, and traditional flap-making pattern were risk factors for OBLs. A Larger corneal diameter was associated with a higher incidence of hard OBL when applying the traditional flap-making process. CONCLUSION: More myopia, thicker CCT, and larger corneal diameter were risk factors for OBL development during flap creation, whereas a flap-making pattern with an offset between flap-cut and side-cut could reduce the incidence of OBL.

Time Outdoors in Reducing Myopia: A School-Based Cluster Randomized Trial with Objective Monitoring of Outdoor Time and Light Intensity.

PURPOSE: To evaluate the efficacy of time outdoors per school day over 2 years on myopia onset and shift. DESIGN: A prospective, cluster-randomized, examiner-masked, 3-arm trial. PARTICIPANTS: A total of 6295 students aged 6 to 9 years from 24 primary schools in Shanghai, China, stratified and randomized by school in a 1:1:1 ratio to control (n = 2037), test I (n = 2329), or test II (n = 1929) group. METHODS: An additional 40 or 80 minutes of outdoor time was allocated to each school day for test I and II groups. Children in the control group continued their habitual outdoor time. Objective monitoring of outdoor and indoor time and light intensity each day was measured with a wrist-worn wearable during the second-year follow-up. MAIN OUTCOME MEASURES: The 2-year cumulative incidence of myopia (defined as cycloplegic spherical equivalent [SE] of ≤-0.5 diopters [D] in the right eye) among the students without myopia at baseline and changes in SE and axial length (AL) after 2 years. RESULTS: The unadjusted 2-year cumulative incidence of myopia was 24.9%, 20.6%, and 23.8% for control, test I, and II groups, respectively. The adjusted incidence decreased by 16% (incidence risk ratio [IRR], 0.84; 95% confidence interval [CI], 0.72-0.99; P = 0.035) in test I and 11% (IRR = 0.89; 95% CI, 0.79-0.99; P = 0.041) in test II when compared with the control group. The test groups showed less myopic shift and axial elongation compared with the control group (test I: -0.84 D and 0.55 mm, test II: -0.91 D and 0.57 mm, control: -1.04 D and 0.65 mm). There was no significant difference in the adjusted incidence of myopia and myopic shift between the 2 test groups. The test groups had similar outdoor time and light intensity (test I: 127 ± 30 minutes/day and 3557 ± 970 lux/minute; test II: 127 ± 26 minutes/day and 3662 ± 803 lux/minute) but significantly more outdoor time and higher light intensity compared with the control group (106 ± 27 minutes/day and 2984 ± 806 lux/minute). Daily outdoor time of 120 to 150 minutes at 5000 lux/minutes or cumulative outdoor light intensity of 600 000 to 750 000 lux significantly reduced the IRR by 15%～ 24%. CONCLUSIONS: Increasing outdoor time reduced the risk of myopia onset and myopic shifts, especially in nonmyopic children. The protective effect of outdoor time was related to the duration of exposure and light intensity. The dose-response effect between test I and test II was not observed probably because of insufficient outdoor time achieved in the test groups, which suggests that proper monitoring on the compliance on outdoor intervention is critical if one wants to see the protective effect.

Biometric and refractive changes following the monocular application of peripheral myopic defocus using a novel augmented-reality optical system in adults.

The prevalence of myopia is growing at an alarming rate and is associated with axial elongation of the eye. The cause of this undesirable physiological change involves multiple factors. When the magnitude of myopia approaches high levels, this accompanying mechanical effect increases the risk of developing other clinical conditions associated with permanent vision loss. Prior work has investigated how we may halt or reverse this process of axial elongation associated with myopic progression when we expose the eye to a peripheral myopic defocus stimulus. Specifically, the known, short-term response to myopic defocus stimulation is promising and demonstrates the possibility of establishing more permanent effects by regulating the axial length of the eye with specific defocus stimulation. However, how to directly convert these known, short-term effects into more long-term, permanent changes to effectively prevent these unfavourable physiological and refractive changes over time is yet to be understood. Here, we show for the first time that we can produce sustained, long-term reductions in axial length and refractive endpoints with cumulative short-term exposure to specific myopic defocus stimuli using a novel optical design that incorporates an augmented reality optical system. We believe that this technology will have the potential to improve the quality of vision in mankind.

Outdoor exposure in children from Buenos Aires Province, Argentina.

OBJECTIVES: To evaluate myopia risk factors, mainly outdoor exposure and reading habits, in a country with low prevalence of myopia (Buenos Aires Province, Argentina). METHODS: Consecutive children interviewed in a clinical private practice setting were autorefracted under cycloplegia with cyclopentolate 1%. Their parents consented to fill a questionnaire about schooling, tutorial classes, outdoor exposure, reading habits, and cellphone use, both on weekdays and weekends. The Spanish questionnaire was based on past English questionnaires of myopia clinical trials. The spherical equivalent of the right eye was used for the refractive distribution. The average daily hours spent for each activity were calculated. RESULTS: This study involved 115 children aged 10.48 ±â€¯3.65 years (range 5-18 years), with 56.5% being girls. Children had 8 h of schooling per day in 62.6% of cases, and only 14.8 % had tutorial classes after school. There were 38.3% myopes (<-0.50 D), 24.3% hyperopes (>+2.00 D) and the rest were emmetropes. The mean time that these children spent outdoors per day was 3.94 ±â€¯1.45 h (27.60 ±â€¯10.16 h per week). The total mean time spent reading and writing per day was 1.50 ±â€¯0.98 h, and that spent using cellphones and tablets was 2.43 ±â€¯1.66 h. CONCLUSION: In an environment with low myopia prevalence, children spend almoast 4 h per day outdoors, much more than the usual recommendation of 2 h a day for myopia prevention.

The role of ipRGCs in ocular growth and myopia development.

The increasing global prevalence of myopia calls for elaboration of the pathogenesis of this disease. Here, we show that selective ablation and activation of intrinsically photosensitive retinal ganglion cells (ipRGCs) in developing mice induced myopic and hyperopic refractive shifts by modulating the corneal radius of curvature (CRC) and axial length (AL) in an opposite way. Melanopsin- and rod/cone-driven signals of ipRGCs were found to influence refractive development by affecting the AL and CRC, respectively. The role of ipRGCs in myopia progression is evidenced by attenuated form-deprivation myopia magnitudes in ipRGC-ablated and melanopsin-deficient animals and by enhanced melanopsin expression/photoresponses in form-deprived eyes. Cell subtype-specific ablation showed that M1 subtype cells, and probably M2/M3 subtype cells, are involved in ocular development. Thus, ipRGCs contribute substantially to mouse eye growth and myopia development, which may inspire novel strategies for myopia intervention.

Prevalence and Risk Factors of Myopia in Young Adults: Review of Findings From the Raine Study.

Myopia tends to develop and progress fastest during childhood, and the age of stabilization has been reported to be 15-16 years old. Thus, most studies on myopia have centered on children. Data on the refractive error profile in young adulthood - a time in life when myopia is thought to have stabilized and refractive error is unaffected by age-related pathology such as cataract - are limited. The Raine Study has been following a community-based cohort of young adults representative of the general Western Australia population since their prenatal periods in 1989-1991, with eye examinations performed when participants were 20 and 28 years old. At 20 years old, prevalence of myopia in the cohort was 25.8%. Using long-term trajectory of serum vitamin D levels and conjunctival ultraviolet autofluorescence (CUVAF) area to objectively quantify sun exposure, the Raine Study confirmed a negative relationship between time spent outdoors and myopia prevalence. However, prospective studies are required to determine the amount of CUVAF area or serum vitamin D levels associated with time duration. Combining data from the Raine Study and several other cohorts, Mendelian randomization studies have confirmed a link between myopia and a genetic predisposition toward higher education. Several novel potential associations of myopia or ocular biometry were investigated, including fetal growth trajectory, which was found to be significantly associated with corneal curvature at 20 years. By age 28, myopia prevalence had increased to 33.2%. Between 20 and 28 years old, myopia progressed and axial length elongated, on average, by -0.041D/year and 0.02 mm/year, respectively. Smaller CUVAF area at follow-up, female sex, and parental myopia were significant risk factors for myopia incidence and progression between 20 and 28 years. Given the limited research in young adults, further investigations are warranted to confirm the Raine Study findings, as well as identify novel genetic or environmental factors of myopia incidence and progression in this age group.