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

Abstract

I read with interest the editorial by Drs. Saidha and Naismith.1 The corresponding study by Xu et al.2 that reported the sensitivity of detecting previous optic neuritis (ON) is elegant. However, many questions remain. One of the reasons why neurologists in the United States do not use optical coherence tomography (OCT) routinely is because of the high cost of hardware and the continually changing algorithms that are used to perform retinal segmentation. In addition, why not use pattern shift visual evoked response data that shows delayed P100 latencies in most patients, even with visual recovery in detecting previous ON? Although latencies continue to improve up to 2 years after presentation, abnormalities in visual evoked potential (VEP) are seen in 80% at 2 years.3 Hence, OCT metrics (retinal nerve fiber layer and ganglion cell–inner plexiform layer thickness differences between affected and unaffected eyes) cannot be accepted as being superior to a routine VEP evaluation unless both techniques are studied in the same patient cohort(s) by blinded investigators. As current technology stands, both spectral domain OCT and VEP probably do not aid in the diagnosis of ON in the acute setting.