The Bifocal & Atropine in Myopia (BAM) study aims to determine whether combining 0.01% atropine and +2.50-diopter add center-distance soft bifocal contact lenses (SBCL) slows myopia progression more than SBCL alone. The results could provide significant information on the myopia control effect of combining optical and pharmacological treatments.
This article describes the subject characteristics at baseline, the study methods, and the short-term effects of this combination treatment on visual acuity (VA) and vision-related outcomes.
Subjects from the BAM study who met the baseline eligibility criteria were dispensed the combination treatment for 2 weeks to determine final eligibility. Outcome measures included VA at near and distance (Bailey-Lovie logMAR charts), near phoria (modified Thorington), accommodative lag (Grand Seiko WAM-5500), and pupil size (NeurOptics VIP-200 Pupillometer). Compliance was monitored using surveys. Two subgroups in the Bifocal Lenses In Nearsighted Kids study, single-vision contact lens wearers and those who wore +2.50-diopter add SBCL, will serve as the age-matched historical controls for BAM study.
Forty-nine BAM subjects (9.6 ± 1.4 years) were enrolled; mean spherical equivalent cycloplegic autorefraction was −2.33 ± 1.03 diopters. After 2 weeks of treatment, the best-corrected low-contrast (10% Michelson) distance VA was reduced (pre-treatment, +0.09 ± 0.07; post-treatment, +0.16 ± 0.08; P < .0001), but the high-contrast VA at near or distance was unaffected. Near phoria increased by approximately 2△ in the exo direction (P = .01), but the accommodative lag was unchanged. The pupil size was not significantly different between pre-treatment and post-treatment of either the photopic or mesopic condition. Surveys indicated that the subjects wore SBCL 77 ± 22% of waking hours and used atropine 6.4 ± 0.7 days per week.
Two weeks of combination treatment reduced low-contrast distance VA and increased near exophoria slightly, but the subjects were compliant and tolerated the treatment well.
1The Ohio State University College of Optometry, Columbus, Ohio *firstname.lastname@example.org
Submitted: September 4, 2018
Accepted: January 20, 2019
Funding/Support: National Institutes of Health (K23 EY025273; to JH); National Institutes of Health (U10 EY023204); National Institutes of Health (U10 EY023206; to LAJ-J); National Institutes of Health (U10 EY023208; to JJW); National Institutes of Health (U10 EY023210; to DOM); National Institutes of Health (UL1 TR001070); National Institutes of Health (P30 EY007551); and National Institutes of Health (P30 EY005722).
Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest.
Study Registration Information: ClinicalTrials.gov (NCT03312257).
Author Contributions and Acknowledgments: Conceptualization: JH, DOM, LAJ-J, JJW; Data Curation: JH, DOM, LAJ-J, JJW; Formal Analysis: JH; Funding Acquisition: JH; Investigation: JH, DOM, JJW; Methodology: JH, DOM, LAJ-J, JJW; Project Administration: JH, LAJ-J; Supervision: JH, DOM, LAJ-J, JJW; Writing – Original Draft: JH; Writing – Review & Editing: JH, DOM, LAJ-J, JJW.
The authors acknowledge the contributions of Drs. Sina Farsiu and Stephanie Chiu (Duke University; development of the Duke Optical Coherence Tomography Retinal Analysis Program software), Hope Queener (University of Houston; development of MATLAB code to process Duke Optical Coherence Tomography Retinal Analysis Program segmentation output), and Chris Kuether (University of Houston; making instrument modifications) to the completion of this work.