Biomedical subjects

L A Cyert

Publications and source records attributed to L A Cyert.

3 recordsLinked to original sources

PubMed2000

A randomized trial of the effect of single-vision vs. bifocal lenses on myopia progression in children with esophoria.

BACKGROUND: Bifocals have long been thought to reduce progression of childhood myopia. However, this hypothesis has not been definitively evaluated. METHODS: We conducted a randomized clinical trial to test the hypothesis that bifocals slow myopia progression in children with near-point esophoria. Eighty-two myopic children were randomized to single-vision glasses (n = 40) or to bifocals with a +1.50 D add (n = 42) and were followed for 30 months. Refraction was measured by an automated refractor after cycloplegia. The primary outcome was myopia progression defined as the difference between the spherical equivalent at baseline and at the 30-month examination, averaged over both eyes. RESULTS: Follow-up was incomplete for six children in the bifocal group and one child in the single-vision group. Among the children completing the 30 months of follow up, myopia progression (mean spherical equivalent of the two eyes) averaged 0.99 D for bifocals and 1.24 D for single vision (unadjusted, p = 0.106; adjusted for age, p = 0.046). Treatment groups differed in their cumulative distributions (Kolmogorov-Smirnov procedure, p = 0.031). Evidence for a treatment effect on growth in vitreous chamber depth was similar (p = 0.046 by K.S.). CONCLUSION: Use of bifocals, instead of single-vision glasses, by children with near-point esophoria seemed to slow myopia progression to a slight degree.

Aging↗

PubMed1998

Baseline characteristics in the Myopia Progression Study, a clinical trial of bifocals to slow myopia progression.

BACKGROUND: Retrospective studies have indicated that myopic children with nearpoint esophoria experienced slower myopia progression if they wore bifocal glasses rather than single-vision glasses. A small, 18-month clinical trial also supported that finding, but the results were not statistically significant. The Myopia Progression Study was funded by the National Eye Institute to test more rigorously the efficacy of bifocals, compared with single-vision glasses, in slowing myopia progression in children with nearpoint esophoria. A secondary objective of the study was to identify other variables that might influence the rate of myopia progression. This report describes the design and methods of the Myopia Progression Study and the baseline characteristics of the subjects. METHODS: A 3-year, randomized clinical trial was initiated. Subjects were children between 6 and 12 years of age who were myopic (at least -0.50 D in each eye) and who demonstrated nearpoint esophoria by the von Graefe technique. RESULTS: Eighty-two children were enrolled. After blocking by gender and clinical site (two sites), subjects were randomly assigned to one of the two treatments: correction with single-vision spectacle lenses or correction with bifocal lenses having a +1.50 D add in a flattop segment. The average degree of myopia at baseline was -2.31 D (SD = 1.31 D). CONCLUSION: This clinical trial can be expected to determine the effectiveness of bifocal glasses in slowing the progression of myopia in children with nearpoint esophoria.

Child↗

PubMed1996

Can bifocals slow myopia progression?

BACKGROUND: Retrospective studies have suggested that in children with near point esophoria, bifocals can slow myopia progression by about 50 percent. A prospective study was conducted to test this hypothesis. METHODS: Thirty-two children, all with near point esophoria, were randomly divided into either correction with single-vision or with bifocal lenses containing a +1.25 D and. Axial length and refraction were measured under cycloplegia every 6 months for 18 months. Twenty-eight children completed the study. RESULTS: Myopia progressed at an equal rate in both groups for the first 12 months. Progression was much faster during the first 6 months, which was during the school year, than during the second 6 months, which included all of the summer vacation (0.64 D/yr vs 0.29 D/yr). During the last 6 months, myopia progressed rapidly for children in single-vision lenses (0.80 D/yr) but slowly for those in bifocals (0.37 D/yr). A repeated-measure analysis of variance showed that season of the year had a significant effect on myopia progression (p > 0.002) and that the effect differed for the two treatment groups (p > 0.043). Over the whole 18-month study, myopia progressed at rate of 0.57 D/yr for those in single-vision lenses and 0.39 D/yr in those in bifocals (p = 0.26). CONCLUSIONS: Bifocals seemed to slow myopia progression in these children with near-point esophoria, although a longer-term study with more subjects is needed to confirm this finding. Myopia progressed more rapidly during the school year than during summer vacation.

Adolescent↗