ACUTE EFFECTS OF CERVICAL MANUAL THERAPY ON RETINAL AND CHOROIDAL PERFUSION ASSESSED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY: A PROSPECTIVE RANDOMIZED SHAM-CONTROLLED TRIAL

This prospective randomized sham-controlled trial evaluated the acute effects of a single session of cervical manual therapy (high-velocity low-amplitude manipulation combined with Maitland mobilization) on retinal and choroidal microvascular perfusion in 96 patients with chronic mechanical neck pain. Using optical coherence tomography angiography (OCTA), we measured superficial capillary plexus (SCP) foveal vessel density, deep capillary plexus (DCP) vessel density, radial peripapillary capillary (RPC) density, subfoveal choroidal thickness, and structural parameters at baseline and at 15, 30, 60, and 120 minutes post-intervention. Compared with sham treatment, manual therapy produced significant increases in SCP foveal vessel density (+1.47 percentage points at 60 minutes; p<0.001), DCP parafoveal density (+1.58; p<0.001), RPC density (+1.48; p<0.001), and subfoveal choroidal thickness (+6.82 μm; p<0.001), with peak responses at 60 minutes and partial regression by 120 minutes. No significant changes were observed in structural retinal parameters or foveal avascular zone measurements. No serious adverse events occurred. The findings demonstrate that cervical manual therapy induces a transient, bilateral enhancement of ocular perfusion, suggesting a possible autonomic mechanism. OCTA appears to be a sensitive tool for investigating neurovascular effects of cervical spine interventions.