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Christine De Weger - One of the best experts on this subject based on the ideXlab platform.
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Bifocals reduce strabismus in children with down syndrome evidence from a randomized controlled trial
Acta Ophthalmologica, 2020Co-Authors: Christine De Weger, Nienke Boonstra, Jeroen GoossensAbstract:PURPOSE: Children with Down syndrome (DS) more often have strabismus, refractive errors, accommodative lags and reduced visual acuity (VA) than typically developing children. In this study, we compare the effects of bifocal glasses with those of unifocal glasses in children with DS. Changes in angle of strabismus, accommodation and refractive error were analysed in this paper. METHODS: In a multicentre randomized controlled trial, 119 children with DS, aged 2-16, were randomly allocated for bifocal or unifocal glasses (with full correction of refractive error in cycloplegia). The 15 centres, all in the Netherlands, followed the participants for 1 year. Changes in refractive error, accommodative accuracy, strabismus, binocularity and stereopsis were compared across 4 subsequent visits. RESULTS: Refractive errors and accommodative errors showed no significant change throughout the course of our study in either intervention group. The manifest angle of strabismus, however, reduced significantly in the bifocal group. This improvement was observed shortly after the children received their new correction (~6 weeks) (linear regression: t = 3.652, p < 0.001) and remained present in the final measurements after 1 year (linear regression: t = 3.604, p < 0.001). The percentage of children with positive binocularity and stereo tests showed no significant differences between the groups. CONCLUSION: Bifocals with full correction of refractive error reduce the manifest angle of strabismus within a few weeks. No effects on accommodation, refractive error, stereopsis and binocularity occurred over the course of 1 year.
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Effects of Bifocals on visual acuity in children with Down syndrome: a randomized controlled trial.
Acta ophthalmologica, 2018Co-Authors: Christine De Weger, Nienke Boonstra, Jeroen GoossensAbstract:Purpose Children with Down syndrome (DS) typically have reduced visual acuity (VA) and accommodation lag, but it is unclear whether prescribed glasses should correct both distance VA (DVA) and near VA (NVA) due to the lack of RCTs. We therefore conducted a multicentre RCT to compare the effects of Bifocals designed to correct both DVA and NVA with distance-correcting unifocal glasses in children with DS. Methods A total of 119 children with DS, aged 2-16, were randomly allocated for bifocal or unifocal glasses (with full correction of refraction error in cycloplegia) in 14 Dutch hospitals and followed during 1 year. VA data were analysed in relation to baseline VA with ancova. Results Treatment groups showed no differences at baseline. Shortly after receiving new corrections (~6 weeks), uncrowded NVA (Bifocals 0.18 ± 0.33 LogMar; unifocals 0.09 ± 0.19 LogMar) and crowded NVA with Bifocals (Bifocals 0.13 ± 0.36 LogMar; unifocals 0.08 ± 0.33 LogMar) were significantly better than at baseline, but these short-term improvements in NVA were not significantly different between the two treatments (p > 0.151). The 1-year treatment differences were as follows: significantly larger improvement for Bifocals compared to unifocals in both uncrowded NVA (Bifocals 0.23 ± 0.29 LogMar, unifocals 0.12 ± 0.30 LogMar, p = 0.045) and crowded NVA (Bifocals 0.31 ± 0.28 LogMar; unifocals 0.16 ± 0.30 LogMar, p = 0.017). Improvements in DVA were comparable (Bifocals 0.07 ± 0.21 LogMar, unifocals 0.08 ± 0.22 LogMar, p = 0.565). Children with poor baseline VA improved more. Accommodation lag stayed unchanged. Conclusion After one year, Bifocals with full correction of ametropia led to significantly larger improvement of both uncrowded NVA and crowded NVA in children with DS with accommodation lag compared to unifocals.
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Bifocals in down a study on the effect of Bifocals in children with down syndrome
Journal of Clinical & Experimental Ophthalmology, 2016Co-Authors: Christine De WegerAbstract:N vision is reduced in most children with Down Syndrome (DS). This is an additional barrier achieving their maximum potential in development. DS is one of the most common genetic anomalies, occurring in about 14.6 in 10000 live births in the Netherlands in 2007. In the last two decades many researches has been performed to study the differences in ocular findings between children with and without DS. Some previous smaller studies by J.M. Woodhouse et al (Cardiff UK 2001-2009) and K Nanda Kumar and S.J. Leat (Toronto Canada 2009-2010) showed that bifocal correction could be a tailor-made treatment for children with DS. Therefore we started a study in children with DS in the Netherlands. Bifocals are rarely prescribed. Usually children with DS receive single vision glasses for distance. By means of our multicentre randomized controlled trail (RCT) we aim to establish whom to prescribe Bifocals and to identify possible prognostic determinants (at start, baseline measurement before therapy with Bifocals) for improvement of visual acuity at near. A multicentre randomized controlled trail (RCT) in 15 participating locations in the Netherlands. In order to be able to show differences between the effect of usual care and the new intervention, the Bifocals, we included 110 children, 2-18 years old, with DS and accommodation deficit, who had not worn Bifocals before. Bifocals were prescribed for children (n=55) in the intervention group and single vision glasses for distance were prescribed in the control group (n=55). We study the effect of these two interventions on visual acuity at near and at distance, on accommodation and occurrence of strabismus and task readiness (monitoring executive functions). Inclusion time started June 2015 and was completed March 2016. Baseline measurements such as refractive errors, near visual acuity, distance visual acuity and accommodation deficit will be presented.
Jeroen Goossens - One of the best experts on this subject based on the ideXlab platform.
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Bifocals reduce strabismus in children with down syndrome evidence from a randomized controlled trial
Acta Ophthalmologica, 2020Co-Authors: Christine De Weger, Nienke Boonstra, Jeroen GoossensAbstract:PURPOSE: Children with Down syndrome (DS) more often have strabismus, refractive errors, accommodative lags and reduced visual acuity (VA) than typically developing children. In this study, we compare the effects of bifocal glasses with those of unifocal glasses in children with DS. Changes in angle of strabismus, accommodation and refractive error were analysed in this paper. METHODS: In a multicentre randomized controlled trial, 119 children with DS, aged 2-16, were randomly allocated for bifocal or unifocal glasses (with full correction of refractive error in cycloplegia). The 15 centres, all in the Netherlands, followed the participants for 1 year. Changes in refractive error, accommodative accuracy, strabismus, binocularity and stereopsis were compared across 4 subsequent visits. RESULTS: Refractive errors and accommodative errors showed no significant change throughout the course of our study in either intervention group. The manifest angle of strabismus, however, reduced significantly in the bifocal group. This improvement was observed shortly after the children received their new correction (~6 weeks) (linear regression: t = 3.652, p < 0.001) and remained present in the final measurements after 1 year (linear regression: t = 3.604, p < 0.001). The percentage of children with positive binocularity and stereo tests showed no significant differences between the groups. CONCLUSION: Bifocals with full correction of refractive error reduce the manifest angle of strabismus within a few weeks. No effects on accommodation, refractive error, stereopsis and binocularity occurred over the course of 1 year.
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Effects of Bifocals on visual acuity in children with Down syndrome: a randomized controlled trial.
Acta ophthalmologica, 2018Co-Authors: Christine De Weger, Nienke Boonstra, Jeroen GoossensAbstract:Purpose Children with Down syndrome (DS) typically have reduced visual acuity (VA) and accommodation lag, but it is unclear whether prescribed glasses should correct both distance VA (DVA) and near VA (NVA) due to the lack of RCTs. We therefore conducted a multicentre RCT to compare the effects of Bifocals designed to correct both DVA and NVA with distance-correcting unifocal glasses in children with DS. Methods A total of 119 children with DS, aged 2-16, were randomly allocated for bifocal or unifocal glasses (with full correction of refraction error in cycloplegia) in 14 Dutch hospitals and followed during 1 year. VA data were analysed in relation to baseline VA with ancova. Results Treatment groups showed no differences at baseline. Shortly after receiving new corrections (~6 weeks), uncrowded NVA (Bifocals 0.18 ± 0.33 LogMar; unifocals 0.09 ± 0.19 LogMar) and crowded NVA with Bifocals (Bifocals 0.13 ± 0.36 LogMar; unifocals 0.08 ± 0.33 LogMar) were significantly better than at baseline, but these short-term improvements in NVA were not significantly different between the two treatments (p > 0.151). The 1-year treatment differences were as follows: significantly larger improvement for Bifocals compared to unifocals in both uncrowded NVA (Bifocals 0.23 ± 0.29 LogMar, unifocals 0.12 ± 0.30 LogMar, p = 0.045) and crowded NVA (Bifocals 0.31 ± 0.28 LogMar; unifocals 0.16 ± 0.30 LogMar, p = 0.017). Improvements in DVA were comparable (Bifocals 0.07 ± 0.21 LogMar, unifocals 0.08 ± 0.22 LogMar, p = 0.565). Children with poor baseline VA improved more. Accommodation lag stayed unchanged. Conclusion After one year, Bifocals with full correction of ametropia led to significantly larger improvement of both uncrowded NVA and crowded NVA in children with DS with accommodation lag compared to unifocals.
Cheng Desmond - One of the best experts on this subject based on the ideXlab platform.
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Effect of bifocal and prismatic bifocal spectacles on myopia progression in children: Three-year results of a randomized clinical trial
'American Medical Association (AMA)', 2014Co-Authors: Cheng Desmond, Woo George, Drobe Bjorn, Schmid KatrinaAbstract:Free to read Importance Myopia is a significant public health problem, making it important to determine whether a bifocal spectacle treatment involving near prism slows myopia progression in children. Objective To determine whether bifocal and prismatic bifocal spectacles control myopia in children with high rates of myopia progression and to assess whether the treatment effect is dependent on the lag of accommodation and/or near phoria status. Design, Setting, and Participants This 3-year randomized clinical trial was conducted in a private practice. A total of 135 (73 female and 62 male) Chinese-Canadian children (aged 8-13 years; mean [SE] age, 10.29 [0.15] years; mean [SE] myopia, −3.08 [0.10] D) with myopia progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments. A total of 128 (94.8%) completed the trial. Interventions Single-vision lenses (control, n = 41), +1.50-D executive Bifocals (n = 48), and +1.50-D executive Bifocals with 3-Δ base-in prism in the near segment of each lens (n = 46). Main Outcomes and Measures Myopia progression (primary) measured using an automated refractor following cycloplegia and increase in axial length (secondary) measured using ultrasonography at intervals of 6 months for 36 months. Results Myopia progression over 3 years was an average (SE) of −2.06 (0.13) D for the single-vision lens group, −1.25 (0.10) D for the bifocal group, and −1.01 (0.13) D for the prismatic bifocal group. Axial length increased an average (SE) of 0.82 (0.05) mm, 0.57 (0.07) mm, and 0.54 (0.06) mm, respectively. The treatment effect of Bifocals (0.81 D) and prismatic Bifocals (1.05 D) was significant (P
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Randomized trial of effect of bifocal and prismatic bifocal spectacles on myopic progression: Two-year results
'American Medical Association (AMA)', 2010Co-Authors: Cheng Desmond, Schmid Katrina, Woo George, Drobe BjornAbstract:Objective: To determine whether bifocal and prismatic bifocal spectacles could control myopia in children with high rates of myopic progression. ---------- Methods: This was a randomized controlled clinical trial. One hundred thirty-five (73 girls and 62 boys) myopic Chinese Canadian children (myopia of 1.00 diopters [D]) with myopic progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments: (1) single-vision lenses (n = 41), (2) +1.50-D executive Bifocals (n = 48), or (3) +1.50-D executive Bifocals with a 3–prism diopters base-in prism in the near segment of each lens (n = 46). ---------- Main Outcome Measures: Myopic progression measured by an automated refractor under cycloplegia and increase in axial length (secondary) measured by ultrasonography at 6-month intervals for 24 months. Only the data of the right eye were used. ---------- Results: Of the 135 children (mean age, 10.29 years [SE, 0.15 years]; mean visual acuity, –3.08 D [SE, 0.10 D]), 131 (97%) completed the trial after 24 months. Myopic progression averaged –1.55 D (SE, 0.12 D) for those who wore single-vision lenses, –0.96 D (SE, 0.09 D) for those who wore Bifocals, and –0.70 D (SE, 0.10 D) for those who wore prismatic Bifocals. Axial length increased an average of 0.62 mm (SE, 0.04 mm), 0.41 mm (SE, 0.04 mm), and 0.41 mm (SE, 0.05 mm), respectively. The treatment effect of Bifocals (0.59 D) and prismatic Bifocals (0.85 D) was significant (P < .001) and both bifocal groups had less axial elongation (0.21 mm) than the single-vision lens group (P < .001). ---------- Conclusions: Bifocal lenses can moderately slow myopic progression in children with high rates of progression after 24 months
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Randomized trial of effect of bifocal and prismatic\ud bifocal spectacles on myopic progression
American Medical Association, 2010Co-Authors: Cheng Desmond, Schmid, Katrina L., Woo Geore, Drobe BjornAbstract:Objective: To determine whether bifocal and prismatic bifocal spectacles could control myopia in children with high rates of myopic progression. ----------\ud \ud Methods: This was a randomized controlled clinical trial. One hundred thirty-five (73 girls and 62 boys) myopic Chinese Canadian children (myopia of 1.00 diopters [D]) with myopic progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments: (1) single-vision lenses (n = 41), (2) +1.50-D executive Bifocals (n = 48), or (3) +1.50-D executive Bifocals with a 3–prism diopters base-in prism in the near segment of each lens (n = 46). ----------\ud \ud Main Outcome Measures: Myopic progression measured by an automated refractor under cycloplegia and increase in axial length (secondary) measured by ultrasonography at 6-month intervals for 24 months. Only the data of the right eye were used. ----------\ud \ud Results: Of the 135 children (mean age, 10.29 years [SE, 0.15 years]; mean visual acuity, –3.08 D [SE, 0.10 D]), 131 (97%) completed the trial after 24 months. Myopic progression averaged –1.55 D (SE, 0.12 D) for those who wore single-vision lenses, –0.96 D (SE, 0.09 D) for those who wore Bifocals, and –0.70 D (SE, 0.10 D) for those who wore prismatic Bifocals. Axial length increased an average of 0.62 mm (SE, 0.04 mm), 0.41 mm (SE, 0.04 mm), and 0.41 mm (SE, 0.05 mm), respectively. The treatment effect of Bifocals (0.59 D) and prismatic Bifocals (0.85 D) was significant (P < .001) and both bifocal groups had less axial elongation (0.21 mm) than the single-vision lens group (P < .001). ----------\ud \ud Conclusions: Bifocal lenses can moderately slow myopic progression in children with high rates of progression after 24 months
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Bifocal lens control of myopia progression in children
Queensland University of Technology, 2008Co-Authors: Cheng DesmondAbstract:This research investigated underlying issues that were critical to the success of the bifocal trial and comprised of three studies. The first study evaluated if Chinese-Canadian children were suitable subjects for the bifocal trial. The high prevalence of myopia in Chinese children suggests that genetic input plays a role in myopia development, but the rapid increase in prevalence over the last few decades indicates environmental factors are also important. Since this bifocal trial was conducted in Canada, this work aimed to determine whether Chinese children who had migrated to Canada would still have high myopia prevalence and a high rate of myopia progression. The second study determined the optimal bifocal lens power for myopia treatment and the effect of incorporating base-in prism into the bifocal. In the majority of published myopia control studies, the power of the prescribed near addition was usually predetermined in the belief that the near addition would always help to improve the near focus. In fact, the effect of near addition on the accommodative error might be quite different even for individuals in which the same magnitude of accommodation lag had been measured. Therefore, this work was necessary to guide the selection of bifocal and prism powers most suitable for the subsequent bifocal trial. The third study, the ultimate goal of this research, was to conduct a longitudinal clinical trial to determine if Bifocals and prismatic Bifocals could control myopia progression in children
Drobe Bjorn - One of the best experts on this subject based on the ideXlab platform.
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Effect of bifocal and prismatic bifocal spectacles on myopia progression in children: Three-year results of a randomized clinical trial
'American Medical Association (AMA)', 2014Co-Authors: Cheng Desmond, Woo George, Drobe Bjorn, Schmid KatrinaAbstract:Free to read Importance Myopia is a significant public health problem, making it important to determine whether a bifocal spectacle treatment involving near prism slows myopia progression in children. Objective To determine whether bifocal and prismatic bifocal spectacles control myopia in children with high rates of myopia progression and to assess whether the treatment effect is dependent on the lag of accommodation and/or near phoria status. Design, Setting, and Participants This 3-year randomized clinical trial was conducted in a private practice. A total of 135 (73 female and 62 male) Chinese-Canadian children (aged 8-13 years; mean [SE] age, 10.29 [0.15] years; mean [SE] myopia, −3.08 [0.10] D) with myopia progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments. A total of 128 (94.8%) completed the trial. Interventions Single-vision lenses (control, n = 41), +1.50-D executive Bifocals (n = 48), and +1.50-D executive Bifocals with 3-Δ base-in prism in the near segment of each lens (n = 46). Main Outcomes and Measures Myopia progression (primary) measured using an automated refractor following cycloplegia and increase in axial length (secondary) measured using ultrasonography at intervals of 6 months for 36 months. Results Myopia progression over 3 years was an average (SE) of −2.06 (0.13) D for the single-vision lens group, −1.25 (0.10) D for the bifocal group, and −1.01 (0.13) D for the prismatic bifocal group. Axial length increased an average (SE) of 0.82 (0.05) mm, 0.57 (0.07) mm, and 0.54 (0.06) mm, respectively. The treatment effect of Bifocals (0.81 D) and prismatic Bifocals (1.05 D) was significant (P
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Randomized trial of effect of bifocal and prismatic bifocal spectacles on myopic progression: Two-year results
'American Medical Association (AMA)', 2010Co-Authors: Cheng Desmond, Schmid Katrina, Woo George, Drobe BjornAbstract:Objective: To determine whether bifocal and prismatic bifocal spectacles could control myopia in children with high rates of myopic progression. ---------- Methods: This was a randomized controlled clinical trial. One hundred thirty-five (73 girls and 62 boys) myopic Chinese Canadian children (myopia of 1.00 diopters [D]) with myopic progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments: (1) single-vision lenses (n = 41), (2) +1.50-D executive Bifocals (n = 48), or (3) +1.50-D executive Bifocals with a 3–prism diopters base-in prism in the near segment of each lens (n = 46). ---------- Main Outcome Measures: Myopic progression measured by an automated refractor under cycloplegia and increase in axial length (secondary) measured by ultrasonography at 6-month intervals for 24 months. Only the data of the right eye were used. ---------- Results: Of the 135 children (mean age, 10.29 years [SE, 0.15 years]; mean visual acuity, –3.08 D [SE, 0.10 D]), 131 (97%) completed the trial after 24 months. Myopic progression averaged –1.55 D (SE, 0.12 D) for those who wore single-vision lenses, –0.96 D (SE, 0.09 D) for those who wore Bifocals, and –0.70 D (SE, 0.10 D) for those who wore prismatic Bifocals. Axial length increased an average of 0.62 mm (SE, 0.04 mm), 0.41 mm (SE, 0.04 mm), and 0.41 mm (SE, 0.05 mm), respectively. The treatment effect of Bifocals (0.59 D) and prismatic Bifocals (0.85 D) was significant (P < .001) and both bifocal groups had less axial elongation (0.21 mm) than the single-vision lens group (P < .001). ---------- Conclusions: Bifocal lenses can moderately slow myopic progression in children with high rates of progression after 24 months
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Randomized trial of effect of bifocal and prismatic\ud bifocal spectacles on myopic progression
American Medical Association, 2010Co-Authors: Cheng Desmond, Schmid, Katrina L., Woo Geore, Drobe BjornAbstract:Objective: To determine whether bifocal and prismatic bifocal spectacles could control myopia in children with high rates of myopic progression. ----------\ud \ud Methods: This was a randomized controlled clinical trial. One hundred thirty-five (73 girls and 62 boys) myopic Chinese Canadian children (myopia of 1.00 diopters [D]) with myopic progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments: (1) single-vision lenses (n = 41), (2) +1.50-D executive Bifocals (n = 48), or (3) +1.50-D executive Bifocals with a 3–prism diopters base-in prism in the near segment of each lens (n = 46). ----------\ud \ud Main Outcome Measures: Myopic progression measured by an automated refractor under cycloplegia and increase in axial length (secondary) measured by ultrasonography at 6-month intervals for 24 months. Only the data of the right eye were used. ----------\ud \ud Results: Of the 135 children (mean age, 10.29 years [SE, 0.15 years]; mean visual acuity, –3.08 D [SE, 0.10 D]), 131 (97%) completed the trial after 24 months. Myopic progression averaged –1.55 D (SE, 0.12 D) for those who wore single-vision lenses, –0.96 D (SE, 0.09 D) for those who wore Bifocals, and –0.70 D (SE, 0.10 D) for those who wore prismatic Bifocals. Axial length increased an average of 0.62 mm (SE, 0.04 mm), 0.41 mm (SE, 0.04 mm), and 0.41 mm (SE, 0.05 mm), respectively. The treatment effect of Bifocals (0.59 D) and prismatic Bifocals (0.85 D) was significant (P < .001) and both bifocal groups had less axial elongation (0.21 mm) than the single-vision lens group (P < .001). ----------\ud \ud Conclusions: Bifocal lenses can moderately slow myopic progression in children with high rates of progression after 24 months
Katrina L. Schmid - One of the best experts on this subject based on the ideXlab platform.
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Effect of bifocal and prismatic bifocal spectacles on myopia progression in children
2014Co-Authors: Desmond Cheng, George C. Woo, Bjorn Drobe, Katrina L. SchmidAbstract:Free to read Importance Myopia is a significant public health problem, making it important to determine whether a bifocal spectacle treatment involving near prism slows myopia progression in children. Objective To determine whether bifocal and prismatic bifocal spectacles control myopia in children with high rates of myopia progression and to assess whether the treatment effect is dependent on the lag of accommodation and/or near phoria status. Design, Setting, and Participants This 3-year randomized clinical trial was conducted in a private practice. A total of 135 (73 female and 62 male) Chinese-Canadian children (aged 8-13 years; mean [SE] age, 10.29 [0.15] years; mean [SE] myopia, −3.08 [0.10] D) with myopia progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments. A total of 128 (94.8%) completed the trial. Interventions Single-vision lenses (control, n = 41), +1.50-D executive Bifocals (n = 48), and +1.50-D executive Bifocals with 3-Δ base-in prism in the near segment of each lens (n = 46). Main Outcomes and Measures Myopia progression (primary) measured using an automated refractor following cycloplegia and increase in axial length (secondary) measured using ultrasonography at intervals of 6 months for 36 months. Results Myopia progression over 3 years was an average (SE) of −2.06 (0.13) D for the single-vision lens group, −1.25 (0.10) D for the bifocal group, and −1.01 (0.13) D for the prismatic bifocal group. Axial length increased an average (SE) of 0.82 (0.05) mm, 0.57 (0.07) mm, and 0.54 (0.06) mm, respectively. The treatment effect of Bifocals (0.81 D) and prismatic Bifocals (1.05 D) was significant (P
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Effect of Bifocal and Prismatic Bifocal Spectacles on Myopia Progression in Children: Three-Year Results of a Randomized Clinical Trial
JAMA ophthalmology, 2014Co-Authors: Desmond Cheng, George C. Woo, Bjorn Drobe, Katrina L. SchmidAbstract:Importance Myopia is a significant public health problem, making it important to determine whether a bifocal spectacle treatment involving near prism slows myopia progression in children. Objective To determine whether bifocal and prismatic bifocal spectacles control myopia in children with high rates of myopia progression and to assess whether the treatment effect is dependent on the lag of accommodation and/or near phoria status. Design, Setting, and Participants This 3-year randomized clinical trial was conducted in a private practice. A total of 135 (73 female and 62 male) Chinese-Canadian children (aged 8-13 years; mean [SE] age, 10.29 [0.15] years; mean [SE] myopia, −3.08 [0.10] D) with myopia progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments. A total of 128 (94.8%) completed the trial. Interventions Single-vision lenses (control, n = 41), +1.50-D executive Bifocals (n = 48), and +1.50-D executive Bifocals with 3-Δ base-in prism in the near segment of each lens (n = 46). Main Outcomes and Measures Myopia progression (primary) measured using an automated refractor following cycloplegia and increase in axial length (secondary) measured using ultrasonography at intervals of 6 months for 36 months. Results Myopia progression over 3 years was an average (SE) of −2.06 (0.13) D for the single-vision lens group, −1.25 (0.10) D for the bifocal group, and −1.01 (0.13) D for the prismatic bifocal group. Axial length increased an average (SE) of 0.82 (0.05) mm, 0.57 (0.07) mm, and 0.54 (0.06) mm, respectively. The treatment effect of Bifocals (0.81 D) and prismatic Bifocals (1.05 D) was significant ( P P P P = .03). The treatment effect of both Bifocals and prismatic Bifocals was independent of the near phoria status. Conclusions and Relevance Bifocal spectacles can slow myopia progression in children with an annual progression rate of at least 0.50 D after 3 years. These results suggest that prismatic Bifocals are more effective for myopic children with low lags of accommodation. Trial Registration clinicaltrials.gov Identifier:NCT00787579
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Bifocal lens control of myopic progression in children.
Clinical & experimental optometry, 2010Co-Authors: Desmond Cheng, George C. Woo, Katrina L. SchmidAbstract:This research investigated underlying issues that were critical to the success of the bifocal trial and comprised of three studies. The first study evaluated if Chinese-Canadian children were suitable subjects for the bifocal trial. The high prevalence of myopia in Chinese children suggests that genetic input plays a role in myopia development, but the rapid increase in prevalence over the last few decades indicates environmental factors are also important. Since this bifocal trial was conducted in Canada, this work aimed to determine whether Chinese children who had migrated to Canada would still have high myopia prevalence and a high rate of myopia progression. The second study determined the optimal bifocal lens power for myopia treatment and the effect of incorporating base-in prism into the bifocal. In the majority of published myopia control studies, the power of the prescribed near addition was usually predetermined in the belief that the near addition would always help to improve the near focus. In fact, the effect of near addition on the accommodative error might be quite different even for individuals in which the same magnitude of accommodation lag had been measured. Therefore, this work was necessary to guide the selection of bifocal and prism powers most suitable for the subsequent bifocal trial. The third study, the ultimate goal of this research, was to conduct a longitudinal clinical trial to determine if Bifocals and prismatic Bifocals could control myopia progression in children.
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Randomized Trial of Effect of Bifocal and Prismatic Bifocal Spectacles on Myopic Progression: Two-Year Results
Archives of ophthalmology (Chicago Ill. : 1960), 2010Co-Authors: Desmond Cheng, George C. Woo, Katrina L. Schmid, Bjorn DrobeAbstract:Objective To determine whether bifocal and prismatic bifocal spectacles could control myopia in children with high rates of myopic progression. Methods This was a randomized controlled clinical trial. One hundred thirty-five (73 girls and 62 boys) myopic Chinese Canadian children (myopia of ≥1.00 diopters [D]) with myopic progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments: (1) single-vision lenses (n = 41), (2) +1.50-D executive Bifocals (n = 48), or (3) +1.50-D executive Bifocals with a 3–prism diopters base-in prism in the near segment of each lens (n = 46). Main Outcome Measures Myopic progression measured by an automated refractor under cycloplegia and increase in axial length (secondary) measured by ultrasonography at 6-month intervals for 24 months. Only the data of the right eye were used. Results Of the 135 children (mean age, 10.29 years [SE, 0.15 years]; mean visual acuity, −3.08 D [SE, 0.10 D]), 131 (97%) completed the trial after 24 months. Myopic progression averaged −1.55 D (SE, 0.12 D) for those who wore single-vision lenses, −0.96 D (SE, 0.09 D) for those who wore Bifocals, and −0.70 D (SE, 0.10 D) for those who wore prismatic Bifocals. Axial length increased an average of 0.62 mm (SE, 0.04 mm), 0.41 mm (SE, 0.04 mm), and 0.41 mm (SE, 0.05 mm), respectively. The treatment effect of Bifocals (0.59 D) and prismatic Bifocals (0.85 D) was significant (P Conclusions Bifocal lenses can moderately slow myopic progression in children with high rates of progression after 24 months. Applications to Clinical Practice Bifocal spectacles may be considered for slowing myopic progression in children with an annual progression rate of at least 0.50 D. Trial Registration clinicaltrials.gov Identifier:NCT00787579
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Randomized Trial of Effect of Bifocal and Prismatic Bifocal Spectacles on Myopic Progression
2010Co-Authors: Desmond Cheng, George C. Woo, Katrina L. Schmid, Bjorn DrobeAbstract:progression averaged −1.55 D (SE, 0.12 D) for those who wore single-vision lenses, −0.96 D (SE, 0.09 D) for those who wore Bifocals, and −0.70 D (SE, 0.10 D) for those who wore prismatic Bifocals. Axial length increased an average of 0.62 mm (SE, 0.04 mm), 0.41 mm (SE, 0.04 mm), and 0.41 mm (SE, 0.05 mm), respectively. The treatment effect of Bifocals (0.59 D) and prismatic Bifocals (0.85 D) was significant (P.001) and both bifocal groups had less axial elongation (0.21 mm) than the singlevision lens group (P.001).