The role of Optical Coherence Tomography in optic neuropathies

Optical neuropathies are neuro-ophthalmologic disorders, the main symptoms of which are the decrease of visual acuity and the alteration of the color vision. Optical coherence tomography has been one of the most important innovations in ophthalmology, which offered the possibility to analyze specific structures of the retina. Optical coherence tomography performs in vivo, real-time, noncontact scanning and provides cross-sectional and volumetric images with a resolution approaching that of histology. Optical coherence tomography offers the opportunity to study neurological diseases in an objective and non-invasive manner. The measurements of retinal nerve fiber layer can be an objective measurement of nerve swelling or nerve atrophy. By analyzing the ganglion cell complex, optical coherence tomography can help detect early axonal damage and may predict the visual outcome. It can be useful for diagnosis and follow-up of optic nerve and chiasmal compressive diseases. Furthermore, optical coherence tomography is useful in patients with multiple sclerosis in distinguishing macular disease from optic neuritis and in monitoring the treatment. Multiple studies and clinical observations support the importance of optical coherence tomography in the diagnosis, treatment, and follow-up of optic neuropathies. Abbreviations: OCT = optical coherence tomography, VA = visual acuity, RNFL = retinal nerve fiber layer, GCL = ganglion cells layer, MS = multiple sclerosis, ON = optic neuropathy, NAION = non-arteritic ischemic anterior optic neuropathy, LHON = Leber hereditary optic neuropathy, RE = right eye, LE = left eye