LETTER

Detection of optic disc oedema using optical coherence tomography We read with great interest the study by Vartin C and associates,1 describing the role of spectral domain optical coherence tomography (OCT) for the detection of optic disc oedema. Currently, the standard method for the diagnosis of disc oedema is fundus examination. Obviously, the detection of moderate to severe disc oedema is easy. Patients with small cupless discs (so-called crowded discs) may have a prominent optic nerve head which looks like a mild disc oedema. In this subset of patients, the differentiation of oedematous from non-oedematous discs is problematic, and at this time, the ancillary test may be helpful.2 3 In other words, each instrument to be used for detection of disc oedema should be able to differentiate mild disc oedema from normal, small, cupless discs. The OCT features of the optic nerve of the eyes with small cupless discs may be different from normal eyes. Figure 1 shows the fundus photography of a 40-year-old Figure 1 Fundus photography and fluoresceine angiography of a patient with crowded disc. Figure 2 Optical coherence tomography of the optic nerve heads of both eyes. The average retinal thickness in four quadrants are shown in overlay images (right)