Gw. Fulk et al., BASE-LINE CHARACTERISTICS IN THE MYOPIA PROGRESSION STUDY, A CLINICAL-TRIAL OF BIFOCALS TO SLOW MYOPIA PROGRESSION, Optometry and vision science, 75(7), 1998, pp. 485-492
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-m
onth 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 prog
ression in children with nearpoint esophoria. A secondary objective of
the study was to identify other variables that might influence the ra
te of myopia progression. This report describes the design and methods
of the Myopia Progression Study and the baseline characteristics of t
he subjects. Methods. A 3-year, randomized clinical trial was initiate
d. Subjects were children between 6 and 12 years of age who were myopi
c (at least -0.50 D in each eye) and who demonstrated nearpoint esopho
ria by the von Graefe technique. Results. Eighty-two children were enr
olled. After blocking by gender and clinical site (two sites), subject
s were randomly assigned to one of the two treatments: correction with
single-vision spectacle lenses or correction with bifocal lenses havi
ng 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 c
an be expected to determine the effectiveness of bifocal glasses in sl
owing the progression of myopia in children with nearpoint esophoria.