Researchers from the Queensland University of Technology, Brisbane, Australia, followed 135 myopic Chinese Canadian children (with a mean age of 10 years) with myopic progression of at least 0.50D in the preceding year. The children were managed in one of three ways: single-vision lenses, +1.50D executive bifocals or +1.50D executive bifocals with a 3-prism diopter base-in prism in the near segment of the lenses. Progression was monitored with an automated refractor under cycloplegia, and axial length was measured with ultrasonography every six months.
Two years later, the single-vision group had progressed an average of -1.55D, the bifocal group had progressed -0.96D and the prismatic bifocal group had progressed -0.70D. Axial length increased 0.62mm in the first group and 0.41mm in both bifocal groups.
So, over the course of two years, bifocal spectacles successfully helped slow myopic progression in children, researchers concluded. They recommend that bifocals be considered for children who show an annual myopic progression rate of at least 0.50D.
Cheng D, Schmid KL, Woo GC, Drobe B. Randomized trial of effect of bifocal and prismatic bifocal spectacles on myopic progression: two-year results. Arch Ophthalmol. 2010 Jan;128(1):12-9.