Short-Term Effect of Spinal Manipulation on the Magnitude of Exophoria in Adults Who Are Asymptomatic: A Randomized Controlled Trial.

Objective: This study aimed to assess the immediate and short-term effects of cervical spinal manipulation (SM), compared with a placebo, on the magnitude of near and distance exophoria in adults with asymptomatic exophoria.

Methods: In this single-blind, randomized controlled trial, individuals with a clinical diagnosis of horizontal exophoria confirmed with the prism alternating cover test (PACT) were allocated to a single intervention session using a high-velocity, low-amplitude cervical SM technique or a sham intervention (manual contact under the head). Outcomes were the magnitude of horizontal heterophoria, as a measure of binocular vision efficiency at near (40 cm) or distance (4 m) fixation, using the PACT.