How to Measure Fundus Torsion Using iPhone Photo Editing Tools

Objective torsion can be recorded by assessment of the fovea–disc relationship. In normal patients, the fovea is located between the midpoint and the lower border of the optic disc, around 0.3 disc diameters below a horizontal line drawn through the center of the disc. Patients with torsion will have a shift in the position of the fovea relative to the optic disc. With extorsion, the fovea is shifted below the inferior border of the optic disc, whereas intorsion shifts the fovea higher than the midpoint of the optic nerve. In this video, Dr. Mahmoud Ismail demonstrates an easy and novel technique (Photocheck) to measure subjective fundus torsion using standard iPhone photo editing tools.

Financial Disclosures: Dr. Mahmoud Ismail discloses no financial relationships.