A technique for standardizing disk foveal angle measurement.

Ocular torsion can been measured by perimetry, double Maddox rod, Bagolini glasses, indirect ophthalmoscopy lens, slit-lamp biomicroscopy, synoptophore, and fundus photography. Wide variations have been reported in the measurement of the disk foveal angle (DFA) using fundus photography. We describe a technique for measuring the DFA, formed by a horizontal line extending from the center of the optic disk and a line from the center of disk to the fovea, using Microsoft PowerPoint and ImageJ software.