Optical coherence tomography angiography for the measurement of optic disc: Macular relationship

Fundus photography is the gold standard for assessing ocular torsion over the last 30 years. However, it is not a precise and reproducible tool during clinical practice. Optical coherence tomography angiography is characterized by precise identification of the macula and the optic disc, and it could be an effective method to easily calculate the angle of ocular torsion, compared to fundus photography. The aim of this study was to show whether any difference in the measurement and the accuracy of the angle of torsion between the head of the optic nerve and the fovea was present.

This is a prospective single-, referral-center study conducted at the San Giuseppe Hospital in Milan on 80 eyes of 40 adult patients, included in a random-sample way. Exclusion criteria were non-cooperation, higher refractive errors of ±3 diopters, retinal and optic disc pathologies, and ocular movement disorders.

Patients' mean age was 54.3 ± 16.3 (range: 22-83) years. The angle measured by the fundus camera was 7.78° ± 3.04°, while the angle measured by the angiography was 7.09° ± 3.08° (p = .035). The mean interocular difference was 1.54° ± 3.42° for fundus photography and 0.5° ± 4.71° for angiography (p = .013).

Optical coherence tomography angiography is a very useful, fast, precise, reproducible, and reliable technique in cooperative subjects, not inferior to the fundus camera and less prone to human error.