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Cai J, Zhou Y, Chen X, Huang X, Li L, Zhu Y, Cai Q, Huang J, Sun Z. Is refractive error a factor affecting scoliosis? PLoS One 2024; 19:e0303324. [PMID: 38739623 PMCID: PMC11090344 DOI: 10.1371/journal.pone.0303324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 04/24/2024] [Indexed: 05/16/2024] Open
Abstract
BACKGROUND Scoliosis is one of the most common surgical disorders of the pediatric spine. Refractive errors are commonly associated with vision impairment worldwide. However, it is currently unclear whether refractive error correlates directly with the development of scoliosis. METHODS A cross-sectional study was performed in 2023, and a stratified cluster sampling technique was employed among school-aged students in Nantong City, China. Univariate and multivariate logistic regression analyses were used to investigate specific correlations between scoliosis and related parameters; various types of refractive errors were also included in the study. RESULTS The prevalence of scoliosis among school-aged students was 2.2% in Nantong city. Multiple logistic regression analyses showed that myopia, hyperopia, astigmatism, and anisometropia were not correlated with the development of scoliosis (all, p≥0.05). Lower body mass index (BMI) [adjusted odds ratio (aOR) = 0.92; 95% confidence interval (CI): 0.88-0.95; p<0.001], living in rural areas (aOR = 1.40; 95% CI: 1.05-1.86; p = 0.020), and older age (aOR = 1.32; 95% CI: 1.25-1.38; p<0.001) had significantly higher risks of scoliosis. CONCLUSIONS Refractive errors did not correlate with the development of scoliosis. However, BMI, living in rural areas and older age did correlate with the development of scoliosis.
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Affiliation(s)
- Jianru Cai
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Yue Zhou
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Xiaojuan Chen
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Xiaobo Huang
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Lele Li
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Yan Zhu
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Qi Cai
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Jianping Huang
- Nantong Center for Disease Control and Prevention in Jiangsu Province, Jiangsu Province, China
| | - ZhiMin Sun
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
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Harb EN, Sawai ES, Wildsoet CF. Indoor and outdoor human behavior and myopia: an objective and dynamic study. Front Med (Lausanne) 2023; 10:1270454. [PMID: 38020131 PMCID: PMC10643732 DOI: 10.3389/fmed.2023.1270454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/12/2023] [Indexed: 12/01/2023] Open
Abstract
Significance Myopia holds significant public health concern given its social, ocular disease and economic burdens. Although environmental factors are primarily to blame for the rapid rise in prevalence, key risk factors remain unresolved. Purpose The aim of this study was to objectively characterize, using a wearable technology, the temporal indoor and outdoor behavioral patterns and associated environmental lighting characteristics of young myopic and nonmyopic University students. Methods Participants were recruited to continuously wear an Actiwatch for 3 weeks, during either or both academic and non-academic periods. The device allows continuous recording of activity and incident light. Recorded illuminance levels were used as a proxy for outdoors (>1,000 lux), with the dynamics (interval frequency and duration) of indoor and outdoor activities, as well as lighting characteristics derived. In addition, participant input regarding near work was obtained daily. Participants were classified by both myopia and axial length status (based on collected refractive error and biometry data) for the purpose of data analysis. Result A total of 55 students, aged 18 to 25 years of age, participated. Overall, the dosing of indoor and outdoor activities was similar across participants, regardless of myopia status, during the academic period. Nonetheless, an apparent difference in the timing of outdoor activities was noted with myopes going outdoors later in the day, particularly during the weekend (p = 0.03). While a trend was observed between increased lighting levels experienced outdoors and shorter axial lengths, there was no significant relationship with myopia status. Noteworthy, participants generally significantly overestimated time spent outdoors, compared to Actiwatch-derived estimates of the same. Conclusion While the findings from this cohort of young adult students did not reveal substantial myopia-related differences in behavior, the power of a more objective and dynamic approach to quantifying behavior cannot be understated, providing argument for general adoption of wearable technologies in future clinical myopia studies.
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Affiliation(s)
- Elise N. Harb
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, CA, United States
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Zhou Y, Zhang XF, Chen XJ, Wang M, Cai JR, Xiong YJ, Song Y, Sun ZM. Prevalence of anisometropia and influencing factors among school-age children in Nantong, China: a cross-sectional study. Front Public Health 2023; 11:1190285. [PMID: 37397717 PMCID: PMC10307961 DOI: 10.3389/fpubh.2023.1190285] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 05/25/2023] [Indexed: 07/04/2023] Open
Abstract
Objective To investigate the prevalence of anisometropia and associated parameters among school-aged children in Nantong, China. Methods This school-based, cross-sectional study examined students from primary schools, junior high schools, and senior high schools in an urban area of Nantong, China. Univariate and multivariate logistic regression analyses were used to investigate the specific correlations between anisometropia and related parameters. Non-cycloplegic autorefraction was assessed for each student. Anisometropia was defined as the spherical equivalent refraction (SE) difference ≥ 1.0 D between eyes. Results A total of 9,501 participants were validated for analyses, of which 53.2% (n = 5,054) were male, and 46.8% (n = 4,447) were female. The mean of age was 13.32 ± 3.49 years, ranging from 7-19 years. The overall prevalence of anisometropia was 25.6%. Factors such as myopia, scoliosis screening positive, hyperopia, female sex, older age, and higher weight had a significantly higher risk of anisometropia (p < 0.05). Conclusion There was a high prevalence of anisometropia in school-age children. Some physical examination parameters are closely related to children's anisometropia, especially myopia and scoliosis. Preventing myopia and controlling its progression may be the most important ways to reduce the prevalence of anisometropia. Correcting scoliosis may be an important factor in controlling the prevalence of anisometropia, and maintaining good reading and writing posture may be helpful in controlling the prevalence of anisometropia.
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Affiliation(s)
- Yue Zhou
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
| | - Xiao Fang Zhang
- Department of Nantong Fifth People’s Hospital, Nantong, Jiangsu, China
| | - Xiao Juan Chen
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
| | - Min Wang
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
| | - Jian Ru Cai
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
| | - Yao Jia Xiong
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
| | - Yu Song
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
| | - Zhi Min Sun
- Department of Ophthalmology, Second Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
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Chay IW, Lin ST, Lim EWL, Heng WJ, Bin Ismail MA, Tan MCL, Zhao PSB, Nah GKM, Ang BCH. Higher order aberrations and visual function in a young Asian population of high myopes. Heliyon 2023; 9:e14901. [PMID: 37151700 PMCID: PMC10161382 DOI: 10.1016/j.heliyon.2023.e14901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 03/11/2023] [Accepted: 03/21/2023] [Indexed: 05/09/2023] Open
Abstract
Purpose To examine the associations between higher order aberrations (HOAs), visual performance, demographics, and ocular characteristics in a young Asian population with high myopia. Methods This was a retrospective review of military pre-enlistees conducted between March 2014 to September 2018. Visual acuity and contrast sensitivity were tested under photopic, mesopic and simulated night conditions. Ocular, corneal and internal HOAs were measured with a Hartmann-Shack wavefront aberrometer (KR-1W, Topcon Co., Tokyo, Japan). Results 522 eyes of 263 consecutive subjects with severe high myopia (defined as spherical equivalent refraction [SER] ≤ -10.00D) in at least one eye, and high myopia (SER ≤ -6.00D) in the fellow eye, [mean (SD) SER -11.85 (2.03D)] were analysed. The mean (SD) age of subjects was 18.5 (1.6) years. Chinese eyes had significantly greater internal total HOA root-mean-square (RMS) compared to Malay eyes [mean difference (SD) 0.0246 (0.007) μm, p < 0.001). More negative SER was associated with greater ocular total HOA (p = 0.038), primary coma (p = 0.003) and tetrafoil (p = 0.025) RMS, as well as more positive ocular (p = 0.003) and internal primary spherical aberration (p = 0.009). Greater ocular total HOAs was associated with reduced visual acuity in simulated night conditions and low contrast, decreased contrast sensitivity under mesopic and simulated night conditions (all p < 0.05). Conclusions Greater HOAs were associated with Chinese ethnicity and more negative SER in a young Asian population with high myopia. Greater HOAs were associated with poorer visual performance in low luminance and reduced contrast conditions.
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Affiliation(s)
- Isaac W. Chay
- Vision Performance Centre, Military Medicine Institute, Singapore Armed Forces Medical Corps, Singapore
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
| | - Sheng Tong Lin
- DSO National Laboratories, Defence Medical and Environmental Research Institute, Singapore
| | - Edmund WL. Lim
- Vision Performance Centre, Military Medicine Institute, Singapore Armed Forces Medical Corps, Singapore
| | - Wee Jin Heng
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
| | | | | | - Paul SB. Zhao
- Department of Ophthalmology, National University Health System, Singapore
| | - Gerard KM. Nah
- Department of Ophthalmology, National University Health System, Singapore
- W Eye Clinic, Singapore
| | - Bryan CH. Ang
- Vision Performance Centre, Military Medicine Institute, Singapore Armed Forces Medical Corps, Singapore
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
- Department of Ophthalmology, Woodlands Health Campus, Singapore
- Corresponding author. 11 Jln Tan Tock Seng, Singapore 308433.
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Maldoddi R, Thakur S, Verkicharla PK. Near work, light levels and dioptric profile - Which factor dominates and influences the short-term changes in axial length? Ophthalmic Physiol Opt 2023; 43:426-434. [PMID: 36734816 DOI: 10.1111/opo.13103] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 01/14/2023] [Accepted: 01/18/2023] [Indexed: 02/04/2023]
Abstract
PURPOSE Given the agonistic nature of near work to promote axial elongation and the antagonistic nature of time outdoors to prevent myopia, we aimed to investigate the following: (a) how the short-term effect of near work performed outdoors (Experiment 1) influences axial length and (b) how near work performed in two different dioptric profiles (uncluttered and cluttered) alters the changes in central axial length (Experiment 2). METHODS Forty-six adults (age range: 19-32 years) participated in the study. In Experiment 1, 22 participants completed a 15-min distance task and a reading task in both the outdoor (~30,000 lux) and indoor (~70 lux) locations. In Experiment 2, 24 participants performed the same reading task at a study desk in uncluttered and cluttered reading environments. Pre- and post-task ocular biometry measurements were performed for each session using a non-contact biometer. RESULTS In Experiment 1, a significant increase in axial length from baseline was found after performing reading tasks in both outdoor (mean ± SEM: +12.3 ± 3.4 μm, p = 0.001) and indoor locations (+11.9 ± 3.1 μm, p = 0.001). In Experiment 2, axial length increased significantly from baseline to post reading task, in both uncluttered (+17.9 ± 3.5 μm, p < 0.001) and cluttered reading environments (+19.2 ± 2.9 μm, p < 0.001). No significant changes in axial length were observed either between outdoor and indoor locations (p = 0.92) or between the uncluttered and cluttered reading environment (p = 0.75). CONCLUSION Independent of light intensity (outdoor or indoor location) and dioptric profile of the near-work environment (uncluttered or cluttered), a 15-min reading task led to a significant increase in axial length. While the long-term effects of these findings need to be evaluated, practitioners should emphasise how near work can reduce the beneficial effects of time outdoors, while providing recommendations related to time outdoors for myopia control.
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Affiliation(s)
- Rakesh Maldoddi
- Myopia Research Lab, Prof. Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Swapnil Thakur
- Myopia Research Lab, Prof. Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Pavan K Verkicharla
- Myopia Research Lab, Prof. Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, Telangana, India.,Infor Myopia Centre, L V Prasad Eye Institute, Hyderabad, Telangana, India
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Gawne TJ, She Z, Norton TT. Chromatically simulated myopic blur counteracts a myopiagenic environment. Exp Eye Res 2022; 222:109187. [PMID: 35843288 DOI: 10.1016/j.exer.2022.109187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/03/2022] [Accepted: 07/05/2022] [Indexed: 02/09/2023]
Abstract
There is a world-wide epidemic of myopia (nearsightedness), produced largely by human-made environmental visual cues that disrupt the emmetropization feedback mechanism that normally uses defocus cues to produce and maintain eyes in good focus. Previous studies have shown that the wavelength of light affects this process and that myopic defocus can slow the progression of myopia in children. We first asked if continuous exposure to a small cage with restricted viewing distance would produce an environmentally-induced myopia in tree shrews, small diurnal mammals closely related to primates. A group (n = 7) spent 11 days in a small cage with restricted viewing distance; one wall was a video display covered with Maltese crosses that included low-to-high spatial frequencies in the range visible to tree shrews. This group developed myopia (-1.2 ± 0.4 [stderr] D) that was significant relative to a colony group of seven animals (+1.0 ± 0.2 D) raised in mesh cages allowing more distant viewing. We then asked if chromatically-simulated myopic defocus, produced by blurring just the blue channel of the video display, would counteract this environmentally-induced myopia in a group of eight tree shrews. This group instead became significantly hyperopic (+4.0 ± 0.4 D) due to slowed axial elongation. These results demonstrate the high potency of chromatic cues in refractive regulation and may provide the basis for an anti-myopia treatment in humans.
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Affiliation(s)
- Timothy J Gawne
- Department of Optometry and Vision Science, University of Alabama at Birmingham (UAB), USA.
| | - Zhihui She
- Department of Optometry and Vision Science, University of Alabama at Birmingham (UAB), USA
| | - Thomas T Norton
- Department of Optometry and Vision Science, University of Alabama at Birmingham (UAB), USA
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Jiang D, Shi B, Gao H, Guo Y, Zhou S, Zhang Y. Associations between reading and writing postures and myopia among school students in Ningbo, China. Front Public Health 2022; 10:713377. [PMID: 36033776 PMCID: PMC9412161 DOI: 10.3389/fpubh.2022.713377] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 06/24/2022] [Indexed: 01/21/2023] Open
Abstract
Background We conducted this study to investigate the prevalence of myopia among school students in Ningbo and to explore the associations between reading and writing postures and myopia. Methods A population-based and cross-sectional study was conducted, and 3,256 school students aged 8-19 years were recruited. Each enrolled subject was assessed for uncorrected distance visual acuity (UDVA) using a standard logarithmic visual acuity E-chart and a non-cycloplegic autorefraction examination. Self-administered questionnaires were used to investigate myopia-related reading and writing postures and behavioral habits among school students. Results The prevalence of myopia among primary school, middle school, and high school students was 61.49, 81.43, and 89.72%, respectively. Regarding the associations between reading and writing postures and myopia, we identified that a reading distance >33 cm is a protective factor for myopia in female students [odds ratio (OR) = 0.31, 95% confidence interval (CI) = 0.15-0.64], in both primary school (OR = 0.55, 95% CI = 0.30-0.99) and middle school (OR = 0.37, 95% CI = 0.15-0.90). Conclusions A reading distance >33 cm can be used as an additional measure to prevent and control myopia. Proper postural measures for reading and writing may have educational and public health benefits.
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Németh J, Tapasztó B, Aclimandos WA, Kestelyn P, Jonas JB, De Faber JTHN, Januleviciene I, Grzybowski A, Nagy ZZ, Pärssinen O, Guggenheim JA, Allen PM, Baraas RC, Saunders KJ, Flitcroft DI, Gray LS, Polling JR, Haarman AEG, Tideman JWL, Wolffsohn JS, Wahl S, Mulder JA, Smirnova IY, Formenti M, Radhakrishnan H, Resnikoff S. Update and guidance on management of myopia. European Society of Ophthalmology in cooperation with International Myopia Institute. Eur J Ophthalmol 2021; 31:853-883. [PMID: 33673740 PMCID: PMC8369912 DOI: 10.1177/1120672121998960] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/04/2021] [Indexed: 12/13/2022]
Abstract
The prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 is predicted to be 2.6 billion globally, which is expected to rise up to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing substantially and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide and also in Europe. These prevalence estimates indicate the importance of reducing the burden of myopia by means of myopia control interventions to prevent myopia onset and to slow down myopia progression. Due to the urgency of the situation, the European Society of Ophthalmology decided to publish this update of the current information and guidance on management of myopia. The pathogenesis and genetics of myopia are also summarized and epidemiology, risk factors, preventive and treatment options are discussed in details.
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Affiliation(s)
- János Németh
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Beáta Tapasztó
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
- Faculty of Health Sciences, Semmelweis University, Budapest, Hungary
| | | | | | - Jost B Jonas
- Department of Ophthalmology, Heidelberg University, Mannheim, Germany
| | | | | | - Andrzej Grzybowski
- Department of Ophthalmology, University of Warmia and Mazury, Olsztyn, Poland
- Institute for Research in Ophthalmology, Foundation for Ophthalmology Development, Poznan, Poland
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Olavi Pärssinen
- Gerontology Research Centre and Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | | | - Peter M Allen
- Vision and Hearing Sciences Research Centre, Anglia Ruskin University, Cambridge, UK
| | - Rigmor C Baraas
- National Centre for Optics, Vision and Eye Care, University of South-Eastern Norway, Kongsberg, Norway
| | - Kathryn J Saunders
- Centre for Optometry and Vision Science research, Ulster University, Coleraine, UK
| | - Daniel Ian Flitcroft
- Temple Street Children’s Hospital, Dublin, Ireland
- Centre for Eye Research Ireland (CERI) Technological University Dublin, Ireland
| | | | - Jan Roelof Polling
- Department of Ophthalmology and Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Optometry and Orthoptics, Hogeschool Utrecht, University of Applied Science, Utrecht, The Netherlands
| | - Annechien EG Haarman
- Department of Ophthalmology and Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - J Willem L Tideman
- Department of Ophthalmology and Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - James Stuart Wolffsohn
- Optometry and Vision Science, College of Health and Life Sciences, Aston University, Birmingham, UK
| | - Siegfried Wahl
- Institute for Ophthalmic Research, University Tübingen, Tübingen, Germany
- Carl Zeiss Vision International GmbH, Tübingen, Germany
| | - Jeroen A Mulder
- Department of Optometry and Orthoptics, Hogeschool Utrecht, University of Applied Science, Utrecht, The Netherlands
| | | | - Marino Formenti
- Department of Physics, School of Science, University of Padova, Padova, Italy
| | | | - Serge Resnikoff
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
- Brien Holden Vision Institute, Sydney, Australia
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Vyas SA, Kee CS. Early Astigmatism Can Alter Myopia Development in Chickens. Invest Ophthalmol Vis Sci 2021; 62:27. [PMID: 33605983 PMCID: PMC7900885 DOI: 10.1167/iovs.62.2.27] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 01/25/2021] [Indexed: 12/17/2022] Open
Abstract
Purpose To determine the effects of optically imposed astigmatism on myopia development in chickens. Methods Chicks were randomly assigned to wear either spherical (-10D, "LIM", n = 14) or sphero-cylindrical lenses (n ≥ 19 in each group) monocularly for a week from 5 days of age. All lenses imposed the same magnitude of spherical-equivalent hyperopic defocus (-10D), with the two astigmatic magnitudes (-8D or -4D) and four axes (45°, 90°, 135°, or 180°) altered to simulate four subtypes of clinical astigmatism. At the end of the treatment, refractive state was measured for all birds, whereas ocular axial dimensions and corneal curvature were measured for subsets of birds. Results Sphero-cylindrical lens wear produced significant impacts on nearly all refractive parameters (P < 0.001), resulting in myopic-astigmatic errors in the treated eyes. Compared to LIM, the presence of astigmatic blur induced lower myopic error (all except L180 group, P < 0.001) but with higher refractive astigmatism (all P < 0.001) in birds treated with sphero-cylindrical lenses. Distributions of the refractive, axial, and corneal shape parameters in the sphero-cylindrical lens-wear groups indicated that the astigmatic blur had directed the eye growth toward the least hyperopic image plane, with against-the-rule (ATR) and with-the-rule (WTR) astigmatisms typically inducing differential biometric changes. Conclusions The presence of early astigmatism predictably altered myopia development in chicks. Furthermore, the differential effects of WTR and ATR astigmatisms on anterior and posterior segment changes suggest that the eye growth mechanism is sensitive to the optical properties of astigmatism.
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Affiliation(s)
- Sonal Aswin Vyas
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Chea-su Kee
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
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Abstract
Refractive errors are the product of a mismatch between the axial length of the eye and its optical power, creating blurred vision. Uncorrected refractive errors are the second leading cause of worldwide blindness. One refractive error currently attracting significant scientific interest is myopia, mostly owing to the recent rise in its prevalence worldwide and associated ocular disease burden. This increase in myopia prevalence has also been rapid, suggesting environmental influences in addition to any genetic influences on eye growth. This review defines refractive errors, describes their prevalence, and presents evidence for the influence of genetic and environmental factors related to refractive error development.
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Affiliation(s)
- Elise N. Harb
- School of Optometry, University of California, Berkeley, California 94720, USA;,
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Wildsoet CF, Chia A, Cho P, Guggenheim JA, Polling JR, Read S, Sankaridurg P, Saw SM, Trier K, Walline JJ, Wu PC, Wolffsohn JS. IMI - Interventions Myopia Institute: Interventions for Controlling Myopia Onset and Progression Report. Invest Ophthalmol Vis Sci 2019; 60:M106-M131. [PMID: 30817829 DOI: 10.1167/iovs.18-25958] [Citation(s) in RCA: 203] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Myopia has been predicted to affect approximately 50% of the world's population based on trending myopia prevalence figures. Critical to minimizing the associated adverse visual consequences of complicating ocular pathologies are interventions to prevent or delay the onset of myopia, slow its progression, and to address the problem of mechanical instability of highly myopic eyes. Although treatment approaches are growing in number, evidence of treatment efficacy is variable. This article reviews research behind such interventions under four categories: optical, pharmacological, environmental (behavioral), and surgical. In summarizing the evidence of efficacy, results from randomized controlled trials have been given most weight, although such data are very limited for some treatments. The overall conclusion of this review is that there are multiple avenues for intervention worthy of exploration in all categories, although in the case of optical, pharmacological, and behavioral interventions for preventing or slowing progression of myopia, treatment efficacy at an individual level appears quite variable, with no one treatment being 100% effective in all patients. Further research is critical to understanding the factors underlying such variability and underlying mechanisms, to guide recommendations for combined treatments. There is also room for research into novel treatment options.
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Affiliation(s)
- Christine F Wildsoet
- Berkeley Myopia Research Group, School of Optometry and Vision Science Program, University of California Berkeley, Berkeley, California, United States
| | - Audrey Chia
- Singapore Eye Research Institute and Singapore National Eye Center, Singapore
| | - Pauline Cho
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong
| | - Jeremy A Guggenheim
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Jan Roelof Polling
- Erasmus MC Department of Ophthalmology, Rotterdam, The Netherlands.,HU University of Applied Sciences, Optometry and Orthoptics, Utrecht, The Netherlands
| | - Scott Read
- School of Optometry and Vision Science and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Padmaja Sankaridurg
- Brien Holden Vision Institute and School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Seang-Mei Saw
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Klaus Trier
- Trier Research Laboratories, Hellerup, Denmark
| | - Jeffrey J Walline
- The Ohio State University College of Optometry, Columbus, Ohio, United States
| | - Pei-Chang Wu
- Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - James S Wolffsohn
- Ophthalmic Research Group, Aston University, Birmingham, United Kingdom
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Holton V, Hinterlong JE, Tsai CY, Tsai JC, Wu JS, Liou YM. A Nationwide Study of Myopia in Taiwanese School Children: Family, Activity, and School-Related Factors. J Sch Nurs 2019; 37:117-127. [PMID: 31195919 DOI: 10.1177/1059840519850619] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The purpose of the study was to explore how fixed and modifiable family, activity, and school factors affect a student's myopia risk and severity. We used national cross-sectional data from Taiwanese children in Grades 4-6. Bivariate and multivariate analyses, including logistic and ordinary least squares regression, examined factors related to children's myopia status and severity. Age, parent myopia, and school district were associated with risk of myopia. One hour or more per day of near work (OR = 1.26) increased the odds of myopia. The same amount of time in outdoor activities (OR = 0.85) or moderate or vigorous physical activities (OR = 0.82) was associated with lower risk. Near work (β = 0.06), outdoor activity (β = -0.04), and outdoor recess (β = -0.03) predicted myopia severity. To promote healthy vision, nurses should advocate for and implement interventions that increase school children's time outdoors and in physical activities and reduce their time on near work.
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Affiliation(s)
- Valerie Holton
- Institute of Community Health Care, School of Nursing, 34882National Yang-Ming University, Taipei
| | - James E Hinterlong
- Institute of Community Health Care, School of Nursing, 34882National Yang-Ming University, Taipei
| | - Ching-Yao Tsai
- Institute of Public Health, 34882National Yang-Ming University, Taipei
| | - Jen-Chen Tsai
- School of Nursing, 34882National Yang-Ming University, Taipei
| | - Jia Shan Wu
- School of Nursing, 34882National Yang-Ming University, Taipei
| | - Yiing Mei Liou
- Institute of Community Health Care, School of Nursing, 34882National Yang-Ming University, Taipei
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García MG, Ohlendorf A, Schaeffel F, Wahl S. Dioptric defocus maps across the visual field for different indoor environments. BIOMEDICAL OPTICS EXPRESS 2018; 9:347-359. [PMID: 29359108 PMCID: PMC5772587 DOI: 10.1364/boe.9.000347] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 12/19/2017] [Accepted: 12/19/2017] [Indexed: 06/07/2023]
Abstract
One of the factors proposed to regulate the eye growth is the error signal derived from the defocus in the retina and actually, this might arise from defocus not only in the fovea but the whole visual field. Therefore, myopia could be better predicted by spatio-temporally mapping the 'environmental defocus' over the visual field. At present, no devices are available that could provide this information. A 'Kinect sensor v1' camera (Microsoft Corp.) and a portable eye tracker were used for developing a system for quantifying 'indoor defocus error signals' across the central 58° of the visual field. Dioptric differences relative to the fovea (assumed to be in focus) were recorded over the visual field and 'defocus maps' were generated for various scenes and tasks.
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Affiliation(s)
- Miguel García García
- Institute for Ophthalmic Research, Eberhard Karls University Tuebingen, Elfriede-Aulhorn-Straße 7, Tuebingen, 72076, Germany
- Carl Zeiss Vision International GmbH, Turnstrasse 27, Aalen, 73430, Germany
| | - Arne Ohlendorf
- Institute for Ophthalmic Research, Eberhard Karls University Tuebingen, Elfriede-Aulhorn-Straße 7, Tuebingen, 72076, Germany
- Carl Zeiss Vision International GmbH, Turnstrasse 27, Aalen, 73430, Germany
| | - Frank Schaeffel
- Institute for Ophthalmic Research, Eberhard Karls University Tuebingen, Elfriede-Aulhorn-Straße 7, Tuebingen, 72076, Germany
| | - Siegfried Wahl
- Institute for Ophthalmic Research, Eberhard Karls University Tuebingen, Elfriede-Aulhorn-Straße 7, Tuebingen, 72076, Germany
- Carl Zeiss Vision International GmbH, Turnstrasse 27, Aalen, 73430, Germany
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Abstract
PURPOSE It has been hypothesized that central and peripheral refraction, in eyes treated with myopic overnight orthokeratology, might vary with changes in pupil diameter. The aim of this work was to evaluate the axial and peripheral refraction and optical quality after orthokeratology, using ray tracing software for different pupil sizes. METHODS Zemax-EE was used to generate a series of 29 semi-customized model eyes based on the corneal topography changes from 29 patients who had undergone myopic orthokeratology. Wavefront refraction in the central 80 degrees of the visual field was calculated using three different quality metrics criteria: Paraxial curvature matching, minimum root mean square error (minRMS), and the Through Focus Visual Strehl of the Modulation Transfer Function (VSMTF), for 3- and 6-mm pupil diameters. RESULTS The three metrics predicted significantly different values for foveal and peripheral refractions. Compared with the Paraxial criteria, the other two metrics predicted more myopic refractions on- and off-axis. Interestingly, the VSMTF predicts only a marginal myopic shift in the axial refraction as the pupil changes from 3 to 6 mm. For peripheral refraction, minRMS and VSMTF metric criteria predicted a higher exposure to peripheral defocus as the pupil increases from 3 to 6 mm. CONCLUSIONS The results suggest that the supposed effect of myopic control produced by ortho-k treatments might be dependent on pupil size. Although the foveal refractive error does not seem to change appreciably with the increase in pupil diameter (VSMTF criteria), the high levels of positive spherical aberration will lead to a degradation of lower spatial frequencies, that is more significant under low illumination levels.
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Smith EL, Hung LF, Arumugam B, Wensveen JM, Chino YM, Harwerth RS. Observations on the relationship between anisometropia, amblyopia and strabismus. Vision Res 2017; 134:26-42. [PMID: 28404522 DOI: 10.1016/j.visres.2017.03.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/15/2017] [Accepted: 03/19/2017] [Indexed: 11/26/2022]
Abstract
We investigated the potential causal relationships between anisometropia, amblyopia and strabismus, specifically to determine whether either amblyopia or strabismus interfered with emmetropization. We analyzed data from non-human primates that were relevant to the co-existence of anisometropia, amblyopia and strabismus in children. We relied on interocular comparisons of spatial vision and refractive development in animals reared with 1) monocular form deprivation; 2) anisometropia optically imposed by either contact lenses or spectacle lenses; 3) organic amblyopia produced by laser ablation of the fovea; and 4) strabismus that was either optically imposed with prisms or produced by either surgical or pharmacological manipulation of the extraocular muscles. Hyperopic anisometropia imposed early in life produced amblyopia in a dose-dependent manner. However, when potential methodological confounds were taken into account, there was no support for the hypothesis that the presence of amblyopia interferes with emmetropization or promotes hyperopia or that the degree of image degradation determines the direction of eye growth. To the contrary, there was strong evidence that amblyopic eyes were able to detect the presence of a refractive error and alter ocular growth to eliminate the ametropia. On the other hand, early onset strabismus, both optically and surgically imposed, disrupted the emmetropization process producing anisometropia. In surgical strabismus, the deviating eyes were typically more hyperopic than their fellow fixating eyes. The results show that early hyperopic anisometropia is a significant risk factor for amblyopia. Early esotropia can trigger the onset of both anisometropia and amblyopia. However, amblyopia, in isolation, does not pose a significant risk for the development of hyperopia or anisometropia.
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Affiliation(s)
- Earl L Smith
- College of Optometry, University of Houston, TX 77204, USA; Brien Holden Vision Institute, Sydney, Australia.
| | - Li-Fang Hung
- College of Optometry, University of Houston, TX 77204, USA; Brien Holden Vision Institute, Sydney, Australia
| | - Baskar Arumugam
- College of Optometry, University of Houston, TX 77204, USA; Brien Holden Vision Institute, Sydney, Australia
| | | | - Yuzo M Chino
- College of Optometry, University of Houston, TX 77204, USA
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Wielkiewicz RM. Myopia is an Adaptive Characteristic of Vision: Not a Disease or Defect. REVIEW OF GENERAL PSYCHOLOGY 2016. [DOI: 10.1037/gpr0000090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This article proposes that myopia (nearsightedness) is an adaptive characteristic of human vision. Most theories of the evolution of vision assume myopia is a disease or defect that would have resulted in decreased reproductive fitness in the absence of modern corrective lenses. In contrast, the present article argues that myopic individuals may have played important roles in hunter–gatherer groups such as making tools and weapons, and identifying medicinal plants, contributing to individual and group survival. This idea is called the “adaptive myopia hypothesis.” Evidence favoring this hypothesis is reviewed in the context of the metatheory of evolutionary psychology.
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Hua WJ, Jin JX, Wu XY, Yang JW, Jiang X, Gao GP, Tao FB. Elevated light levels in schools have a protective effect on myopia. Ophthalmic Physiol Opt 2016; 35:252-62. [PMID: 25913873 DOI: 10.1111/opo.12207] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 03/02/2015] [Indexed: 02/05/2023]
Abstract
PURPOSE To determine whether elevated light levels in classrooms in rural areas can protect school-age children from myopia onset or myopia progression. METHODS A total of 317 subjects from 1713 eligible students aged six to 14 in four schools located in northeast China participated in the study. Students received a comprehensive eye examination including cycloplegic refraction and ocular biometry, which included axial length (AL), anterior chamber depth (ACD), and corneal curvature (CC) measurement, and completed a questionnaire. The intervention arm included 178 students in two schools with rebuilt elevated lighting systems and the control arm included 139 students in which lighting systems were unchanged. Results for the two arms were compared with a Wilcoxon rank sum test, a chi-squared test or a t-test, as appropriate. Factors that might help explain any differences were explored with multivariate linear regression analysis. RESULTS The median average illuminance of blackboards and desks and uniformity of desk lighting were significantly improved, however, the uniformity of blackboard lighting declined after intervention. At baseline, the mean refraction, AL, CC, ACD and myopia prevalence between the two arms were not significantly different. After 1 year, compared with the control arm the intervention arm had a lower incidence of new myopia onset (4% vs 10%; p = 0.029), a smaller decrease in refractive error among no myopic subjects (-0.25 dioptre [D] vs -0.47 D; p = 0.001), and shorter axial growth for both non-myopic (0.13 vs 0.18 mm; p = 0.023) and myopic subjects (0.20 vs 0.27 mm; p = 0.0001). Multivariate linear regression analysis showed the intervention program, lower hyperopic baseline refraction, lower father's education level, longer time sleeping and less time in screen-viewing activities were associated with less refractive shift in the direction of myopia in non-myopic children. For myopic subjects, myopia progression was significantly associated with family income only. The intervention program and older age had a protective effect on axial growth for both myopic and non-myopic subjects. The father's education level and sleep duration were significantly associated with axial growth in non-myopic children. CONCLUSIONS Elevated light levels in classrooms have a significant effect on myopia onset, decreases in refraction, and axial growth; if the findings of lighting intervention are reproduced in future studies, the ambient light levels in schools should be improved.
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Affiliation(s)
- Wen-Juan Hua
- School of Public Health, Anhui Medical University, Hefei, China
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Vicente T, Ramirez Iñiguez de la Torre MV, Capdevila Garcia L, Lopez Gonzalez AA, Terradillos Garcia MJ, Aguilar Jimenez E. Prevalencia de defectos visuales en trabajadores españoles. Repercusión de variables sociodemográficas y laborales. REVISTA MEXICANA DE OFTALMOLOGÍA 2016. [DOI: 10.1016/j.mexoft.2015.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Queirós A, Lopes-Ferreira D, González-Méijome JM. Astigmatic Peripheral Defocus with Different Contact Lenses: Review and Meta-Analysis. Curr Eye Res 2016; 41:1005-1015. [DOI: 10.3109/02713683.2015.1116585] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Affiliation(s)
- W Neil Charman
- Faculty of Life Sciences, University of Manchester, Manchester, UK
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Li SM, Li SY, Kang MT, Zhou Y, Liu LR, Li H, Wang YP, Zhan SY, Gopinath B, Mitchell P, Wang N. Near Work Related Parameters and Myopia in Chinese Children: the Anyang Childhood Eye Study. PLoS One 2015; 10:e0134514. [PMID: 26244865 PMCID: PMC4526691 DOI: 10.1371/journal.pone.0134514] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/09/2015] [Indexed: 11/29/2022] Open
Abstract
Purpose To examine the associations of near work related parameters with spherical equivalent refraction and axial length in Chinese children. Methods A total of 1770 grade 7 students with mean age of 12.7 years were examined with cycloplegic autorefraction and axial length. Questions were asked regarding time spent in near work and outdoors per day, and near work related parameters. Results Multivariate models revealed the following associations with greater odds of myopia: continuous reading (> 45min), odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.8; close television viewing distance (≤ 3m), OR, 1.7; 95% CI, 1.2-2.3; head tilt when writing, OR, 1.3; 95% CI, 1.1-1.7, and desk lighting using fluorescent vs. incandescent lamp, OR, 1.5; 95% CI, 1.2-2.0. These factors, together with close reading distance and close nib-to-fingertip distance were significantly associated with greater myopia (P<0.01). Among near work activities, only reading more books for pleasure was significantly associated with greater myopia (P=0.03). Television viewing distance (≤ 3 m), fluorescent desk light, close reading distance (≤20 cm) and close nib-to-fingertip distance (≤ 2 cm) were significantly associated with longer axial length (P<0.01). Reading distance, desk light, and reading books for pleasure had significant interaction effects with parental myopia. Conclusions Continuous reading, close distances of reading, television viewing and nib-to-fingertip, head tilt when writing, reading more books for pleasure and use of fluorescent desk light were significantly associated with myopia in 12-year-old Chinese children, which indicates that visual behaviors and environments may be important factors mediating the effects of near work on myopia.
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Affiliation(s)
- Shi-Ming Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology Visual Science Key Lab, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
| | - Si-Yuan Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology Visual Science Key Lab, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
| | - Meng-Tian Kang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology Visual Science Key Lab, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
| | - Yuehua Zhou
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology Visual Science Key Lab, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
| | - Luo-Ru Liu
- Anyang Eye Hospital, Anyang, Henan Province, China
| | - He Li
- Anyang Eye Hospital, Anyang, Henan Province, China
| | - Yi-Peng Wang
- Anyang Eye Hospital, Anyang, Henan Province, China
| | - Si-Yan Zhan
- Department of Epidemiology and Health Statistics, Peking University School of Public Health, Beijing, China
| | - Bamini Gopinath
- Centre for Vision Research, Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia
| | - Paul Mitchell
- Centre for Vision Research, Department of Ophthalmology and Westmead Millennium Institute, University of Sydney, Sydney, Australia
| | - Ningli Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology Visual Science Key Lab, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
- * E-mail:
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González-Méijome JM, Faria-Ribeiro MA, Lopes-Ferreira DP, Fernandes P, Carracedo G, Queiros A. Changes in Peripheral Refractive Profile after Orthokeratology for Different Degrees of Myopia. Curr Eye Res 2015; 41:199-207. [PMID: 25803198 DOI: 10.3109/02713683.2015.1009634] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The purpose of this study was to evaluate the effect of orthokeratology for different degrees of myopia correction in the relative location of tangential (F(T)) and sagittal (F(S)) power errors across the central 70° of the visual field in the horizontal meridian. METHODS Thirty-four right eyes of 34 patients with a mean age of 25.2 ± 6.4 years were fitted with Paragon CRT (Mesa, AZ) rigid gas permeable contact lenses to treat myopia (-2.15 ± 1.26D, range: -0.88 to -5.25D). Axial and peripheral refraction were measured along the central 70° of the horizontal visual field with the Grand Seiko WAM5500 open-field auto-refractor. Spherical equivalent (M), as well as tangential (FT) and sagittal power errors (FS) were obtained. Analysis was stratified in three groups according to baseline spherical equivalent: Group 1 [M(Baseline) = -0.88 to -1.50D; n = 11], Group 2 [M(Baseline) = -1.51 to -2.49D; n = 11], and Group 3 [M(Baseline) = -2.50 to -5.25D; n = 12]. RESULTS Spherical equivalent was significantly more myopic after treatment beyond the central 40° of the visual field (p < 0.001). FT became significantly more myopic for all groups in the nasal and temporal retina with 25° (p ≤ 0.017), 30° (p ≤ 0.007) and 35° (p ≤ 0.004) of eye rotation. Myopic change in FS was less consistent, achieving only statistical significance for all groups at 35° in the nasal and temporal retina (p ≤ 0.045). CONCLUSIONS Orthokeratology changes significantly FT in the myopic direction beyond the central 40° of the visual field for all degrees of myopia. Changes induced by orthokeratology in relative peripheral M, FT and FS with 35° of eye rotation were significantly correlated with axial myopia at baseline.
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Affiliation(s)
- José Manuel González-Méijome
- a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and
| | - Miguel A Faria-Ribeiro
- a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and
| | - Daniela P Lopes-Ferreira
- a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and
| | - Paulo Fernandes
- a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and
| | - Gonzalo Carracedo
- b Department of Optics II (Optometry and Vision) , School of Optics, Universidad Complutense de Madrid , Madrid , Spain
| | - Antonio Queiros
- a Clinical & Experimental Optometry Research Lab, School of Sciences (Optometry), University of Minho , Braga , Portugal and
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Smith EL, Hung LF, Arumugam B. Visual regulation of refractive development: insights from animal studies. Eye (Lond) 2013; 28:180-8. [PMID: 24336296 DOI: 10.1038/eye.2013.277] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/05/2013] [Indexed: 11/09/2022] Open
Abstract
Investigations employing animal models have demonstrated that ocular growth and refractive development are regulated by visual feedback. In particular, lens compensation experiments in which treatment lenses are used to manipulate the eye's effective refractive state have shown that emmetropization is actively regulated by signals produced by optical defocus. These observations in animals are significant because they indicate that it should be possible to use optical treatment strategies to influence refractive development in children, specifically to slow the rate of myopia progression. This review highlights some of the optical performance properties of the vision-dependent mechanisms that regulate refractive error development, especially those that are likely to influence the efficacy of optical treatment strategies for myopia. In this respect, the results from animal studies have been very consistent across species; however, to facilitate extrapolation to clinical settings, results are presented primarily for nonhuman primates. In agreement with preliminary clinical trials, the experimental data show that imposed myopic defocus can slow ocular growth and that treatment strategies that influence visual signals over a large area of the retina are likely to be most effective.
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Affiliation(s)
- E L Smith
- 1] College of Optometry, University of Houston, Houston, TX, USA [2] Vision Cooperative Research Centre, Sydney, Australia
| | - L-F Hung
- 1] College of Optometry, University of Houston, Houston, TX, USA [2] Vision Cooperative Research Centre, Sydney, Australia
| | - B Arumugam
- 1] College of Optometry, University of Houston, Houston, TX, USA [2] Vision Cooperative Research Centre, Sydney, Australia
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Pham HL, Kizuki M, Takano T, Seino K, Watanabe M. Out-of-pocket Costs of Disabilities and Their Association with Household Socioeconomic Status Among School-aged Children in Vietnam. J Rural Med 2013; 8:212-21. [PMID: 25649134 PMCID: PMC4309337 DOI: 10.2185/jrm.2876] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 08/29/2013] [Indexed: 11/27/2022] Open
Abstract
Objective: The aim of this study was to assess the economic burden of
disability of school-aged children and to evaluate the association between disabilities
and household socioeconomic status, as well as the economic burden of disability and
household socioeconomic status in Vietnam. Materials and Methods: Nationally representative data for 9,882 children
aged 6 to 17 years from the Vietnam Household Living Standard Survey 2006 were used.
Disabilities were measured in six basic functional domains, including vision, hearing,
remembering or concentrating, mobility, self-care, and communication. We evaluated the
association between area, household income, educational attainment, or occupation of
household head, and each difficulty. The ratio of health-care expenditure to per capita
household income was compared by presence of a disability as well as household
socioeconomic status. Results: The prevalence of difficulty was 1.9% for vision and 2.3% for at
least one of the other five domains. Difficulty in vision was more prevalent in the richer
households (p=0.001), whereas difficulty in the other five domains was more prevalent in
the poorer households (p=0.002). The ratio of health-care expenditure to per capita
household income was greater than 0.05 in 4.6% of children. The adjusted odds ratio of
children with difficulty in vision having a health-care expenditure share greater than
0.05 compared with children without difficulty was 4.78 (95% CI: 2.95, 7.73; p<0.001),
and that for difficulty in the other five domains was 3.13 (95% CI: 2.04, 4.80;
p<0.001). Among children with difficulty in at least one of the five domains other than
vision, the proportion of children with a health-care expenditure share greater than 0.05
was higher among children from the poorer households (p=0.033). Conclusions: Children with a disability spent more on health care relative
to their income than those without. Visual disability was more prevalent among children
from the richer households, whereas other disabilities were more prevalent among children
from the poorer households.
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Affiliation(s)
- Hong-Luu Pham
- Department of Health Promotion, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan ; National Institute of Labor Protection, Vietnam
| | - Masashi Kizuki
- Department of Health Promotion, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
| | - Takehito Takano
- Department of Health Promotion, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
| | - Kaoruko Seino
- Department of International Health and Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
| | - Masafumi Watanabe
- Department of Health Promotion, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
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Smith EL, Hung LF, Arumugam B, Huang J. Negative lens-induced myopia in infant monkeys: effects of high ambient lighting. Invest Ophthalmol Vis Sci 2013; 54:2959-69. [PMID: 23557736 DOI: 10.1167/iovs.13-11713] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PURPOSE To determine whether high light levels, which have a protective effect against form-deprivation myopia, also retard the development of lens-induced myopia in primates. METHODS Hyperopic defocus was imposed on 27 monkeys by securing -3 diopter (D) lenses in front of one eye. The lens-rearing procedures were initiated at 24 days of age and continued for periods ranging from 50 to 123 days. Fifteen of the treated monkeys were exposed to normal laboratory light levels (∼350 lux). For the other 12 lens-reared monkeys, auxiliary lighting increased the illuminance to 25,000 lux for 6 hours during the middle of the daily 12 hour light cycle. Refractive development, corneal power, and axial dimensions were assessed by retinoscopy, keratometry, and ultrasonography, respectively. Data were also obtained from 37 control monkeys, four of which were exposed to high ambient lighting. RESULTS in normal- and high-light-reared monkeys, hyperopic defocus accelerated vitreous chamber elongation and produced myopic shifts in refractive error. the high light regimen did not alter the degree of myopia (high light: -1.69 ± 0.84 D versus normal light: -2.08 ± 1.12 D; P = 0.40) or the rate at which the treated eyes compensated for the imposed defocus. Following lens removal, the high light monkeys recovered from the induced myopia. The recovery process was not affected by the high lighting regimen. CONCLUSIONS In contrast to the protective effects that high ambient lighting has against form-deprivation myopia, high artificial lighting did not alter the course of compensation to imposed defocus. These results indicate that the mechanisms responsible for form-deprivation myopia and lens-induced myopia are not identical.
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Affiliation(s)
- Earl L Smith
- College of Optometry, University of Houston, Houston, TX 77204-2020, USA.
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Abstract
BACKGROUND Myopia, the most common type of refractive error, is a complex trait including both genetic and environmental factors. Numerous studies have tried to elucidate the aetiology of myopia. However, the exact aetiology of myopia is still unclear. PURPOSE To summarize the worldwide patterns and trends for the prevalence of myopia and to evaluate the risk factors for myopia in population-based studies. RECENT FINDINGS The prevalences of myopia vary across populations of different regions and ethnicities. In population-based studies on children, the prevalence of myopia has been reported to be higher in urban areas and Chinese ethnicity. The regional and racial difference is not so obvious in adult populations aged over 40 years. More time spent on near work, less time outdoors, higher educational level and parental history of myopia have been reported to increase the risk of myopia. CONCLUSIONS Environmental factors play a crucial role in myopia development. The effect of gene-environment interaction on the aetiology of myopia is still controversial with inconsistent findings in different studies. A relatively hyperopic periphery can stimulate compensating eye growth in the centre. Longitudinal cohort studies or randomized clinical trials of community-based health behaviour interventions should be conducted to further clarify the aetiology of myopia.
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Affiliation(s)
- Chen-Wei Pan
- Department of Epidemiology and Public Health, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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