The study was done to determine if the stress of normal eye movements results in gaze-induced globe deformations, vitreous chamber axial length and vitreous chamber axial volume (VCAV) change in highly myopic eyes.
A prospective imaging study was performed on 82 eyes of 43 patients with high myopia with a clinical diagnosis of staphyloma. Three-dimensional MRI scans were acquired while subjects gazed in five directions . Surface renderings were generated, and a processing pipeline was created to automate alignment of the eye and to measure VCAV within 5.5 mm of the visual axis for each eye in every gaze. The Dice coefficient showed significant gaze-induced eye shape changes in all gazes (all p<0.0001). There were no statistically significant gaze-induced VCAV changes when comparing primary gaze to nasal, temporal or upgaze. However, when changing from primary to downgaze, VCAV was increased by +4.79 mm3 (p=0.002, 95% CI 1.71 to 7.86).
The study concluded that the significant gaze-induced globe deformation was noted in all gazes, but a reversible, instantaneous VCAV increase occurred only in downgaze, which is consistent with studies supporting the association of environmental factors such as near work with myopia development and progression.