Optical Coherence Tomography of the Retinal Nerve Fiber Layer

A normal optical coherence tomography (OCT) of the macula is shown highlighting the position of a single retinal ganglion cell and its axon in the retinal nerve fiber layer (Figure 1). The topographical relationship of retinal ganglion cells in the retina to the visual field and position in the anterior visual pathways is demonstrated in Figure 2. A normal OCT of the retinal nerve fiber layer (RNFL) is shown and the various components of a Cirrus OCT of the RNFL printout are explained (Figure 3). Case examples highlighting the use of OCT of the RNFL in a patient with a left optic tract lesion (Figures 4, 5, 6), right optic neuritis (Figures 7, 8, 9), idiopathic intracranial pressure with worsening papilledema (Figures 10, 11, 12) and non-organic vision loss (Figures 13 and 14) are illustrated. Potential pitfalls in interpreting the OCT of the RNFL are described and case examples are shown of a patient with IIH and an off-centered scan in the right eye (Figures 15 and 16), a patient with IIH and a segmentation error in the right eye due to severe optic disc edema (Figures 17, 18) and a patient with bilateral optic neuropathies from non-arteritic anterior ischemic optic neuropathy and an RNFL thickness in the "normal" range in the left eye, but an abnormal left optic nerve (Figures 19 and 20).