Blurry Vision—Clear Connection to the Neck? Retrospective Cross-sectional Study: 145 Patients with Blurry Vision Reporting to an Outpatient Neck Center

The etiology of blurry vision often remains elusive. In this retrospective study, we assessed objective test findings of 145 patients reporting blurry vision at an outpatient neck clinic in 2022. Patients with previously identified causes were excluded. Viable patients underwent digital motion x-ray (videofluoroscopy) and upright cone beam CT scan of the cervical spine, pupillometry, tonometry, and ultrasound of the carotid sheath and eye. Abnormal ocular test results (bilateral totals) include elevated optic nerve sheath diameter (ONSD >12.2 mm) in 142 (98%), excessive percent light constriction (>60%) in 138 (95%), and increased pupil diameters (>8 mm) in 134 (92%). Abnormal cervical structural findings include forward head posture (C6-atlas interval >10 mm) in 145 (100%), vagus nerve degeneration (< 4.2 mm total) in 138 (95%), decreased internal jugular vein cross-sectional area (IJV CSA) at C1 (total < 180 mm) in 143 (99%), decreased depth of curve (< 7 mm) in 128 (89%), and ligamentous cervical instability (LCI) at C1-C2 (total >4 mm) in 124 (88%). Pupil diameter correlated with intraocular pressure (IOP, r=0.26, p=0.002), and LCI C1-C2 correlated with ONSD (r=0.18, p=0.039). These data indicate that some cases of blurry vision may result from ocular pathology due to LCI and loss of lordosis, causing IJV compression and vagus nerve degeneration.