Immediate Effects of Vergence Exercises Using Automatic Dual Rotational Risley Prisms on Accommodative Lag and Facility

Introduction: This study evaluated novel automatic dual rotational Risley prisms (ADRRPs) as a vergence exercise tool for patients with myopia to improve accommodative lag and accommodative facility.Methods: Participants with myopia aged 20-24 years were recruited. After vergence exercises with prisms (treatment group) or plano lenses (control group) using ADRRPs for 10 min, measurements were taken using an open-field autorefractor (Grand Seiko WAM-5500) at viewing distances of 0.4 m and 6.0 m. We measured accommodative facility using a +/- 2.00 D accommodative flipper.Results: A total of 56 participants (treatment group, 39; control group, 17) performed vergence exercises using ADRRPs. Participants in the treatment group showed improvements in accommodative lag at a 0.4 m viewing distance, with measurements of 0.57 D (right eye; OD) and 0.53 D (left eye; OS) and 0.21 D (OD) and 0.27 D (OS) before and after the exercises, respectively (p < 0.001). Over-refractions using an open-field autorefractor with spherical equivalent contact lenses at a 6.0 m viewing distance were - 0.01 +/- 0.30 D (OD) and 0.03 +/- 0.34 D (OS) and 0.15 +/- 0.32 D (OD) and 0.19 +/- 0.28 D (OS) before and after the exercises, respectively (difference + 0.16 D; p < 0.001). Accommodative facility values before and after exercises were 14.88 +/- 3.36 and 15.59 +/- 3.60 cpm, respectively (p < 0.01). No significant differences in accommodative lag, relaxation, and accommodative facility before and after exercise were observed in the control group.Conclusions: Using ADRRPs in vergence exercises can improve accommodative lag, accommodative facility, and accommodative relaxation in adults with myopia. Further research to evaluate persistent and long-term effects is needed.