Optical coherence tomography for diagnosing optic neuritis Are we there yet?

Acute optic neuritis (ON) results in rapid and prominent peripapillary retinal nerve fiber layer (RNFL) and composite ganglion cell and inner plexiform layer (GCIPL) thinning, as measured with optical coherence tomography (OCT). However, the degree of thinning within these layers following ON is heterogeneous, varying across patients, even within the same disease state.(1) Moreover, OCT measures in healthy individuals have a broad range, creating difficulties establishing an absolute diagnostic cutoff for prior ON with good sensitivity and specificity. Whereas earlier generation time-domain OCT could be insensitive to subtle RNFL changes following ON,(2) and less sensitive than visual evoked potentials for confirming prior ON,(3) later generation spectral-domain OCT has improved resolution and reliability, in addition to the ability to measure the advantageous GCIPL, as well as other discrete retinal layers.(1,4)