Abstract
Purpose: :
Tenting of the globe is typically an ominous radiologic sign associated with severe disease, typically infection, trauma or neoplasia and often results in impending severe visual loss. Prompt diagnosis of this condition is critical for early intervention and preservation of vision. Only one technique for identifying this condition, developed for non-digital imaging modlaities has existed and relies on non-standardized and difficult to apply methods. We present a standardized more uniformly applicable technique for identifying this condition using digital imaging.
Methods: :
Study involved analysis of globe images from orbital imaging of normal ( defined as scans obtained for non-traumatic diagnoses and deemed normal by a neuroradiologist and orbital specialist) (N=20), traumatized orbits without globe tenting ( N=10) and orbits with suspected globe tenting (N=4). Axial images were selected at the level of the optic nerve. Digital drawing tools were used to generate a circle of the same diameter as the globe. The circle was then moved to overly the globe. Images were then analyzed as to whether the junction point of the optic nerve and sclera was in line with the drawn circle.
Results: :
Using this technique 20/20 normal globes showed no tenting using the new technique. 10/10 globes in traumatized orbits with normal globes by clinical evaluation showed no tenting. Of globes with known tenting 4/4 were identified as tented using this technique.
Conclusions: :
Recognition of globe tenting is critically important in managing patients with this finding. Given the vastly increased used of digital imaging modalities for the orbit, an easy to apply standardized technique allows examiners to detect distortions of globe shape and make this diagnosis. Limitations of this technique would include congentially "out of round globes" such as those with significant staphyloma that might be considered tented when they are misshapen in a chronic way.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • orbit