Editors' Note: Optical Coherence Tomography for Detection of Asymptomatic Optic Nerve Lesions in Clinically Isolated Syndrome

Abstract

In the article “Optical Coherence Tomography for Detection of Asymptomatic Optic Nerve Lesions in Clinically Isolated Syndrome,” Dr. Outteryck et al. evaluated the ability of intereye retinal thickness difference (IETD) measured by optical coherence tomography (OCT) to detect asymptomatic optic nerve involvement in 130 patients who had presented with clinically isolated syndrome (CIS) within 4.5 months of enrollment. They found that detection of asymptomatic optic nerve lesions in CIS required lower ganglion cell–inner plexiform layer (GC-IPL) IETD thresholds than previously reported and concluded that GC-IPL IETD represents an alternative biomarker to MRI for the detection of such lesions. Although lowering the IETD thresholds may improve the sensitivity of detecting an optic nerve lesion, it comes at the expense of lowering the specificity and this will potentially increase the risk of a false diagnosis of an optic nerve lesion. In response, Dr. Shubhakaran suggests that such a biomarker could help in early intervention to improve the prognosis of patients with multiple sclerosis (MS) and also highlights the utility of OCT in diagnosing macular lesions that may differentiate MS from other disorders. Dr. Shubhakaran notes that OCT is more readily available in certain practice regions than MRI, oligoclonal band testing, and evoked potentials. Responding to these comments, Dr. Outteryck agrees with the utility of OCT in the evaluation of demyelinating diseases, and with the disparate accessibility to OCT and MRI in different parts of the world, but cautions that optic nerve involvement is still not part of the diagnostic criteria for MS for dissemination in space. Noting that optic nerve involvement in patients with CIS is associated with the presence of asymptomatic gadolinium enhancing lesions, Dr. Outteryck argues that optic nerve involvement should be accommodated in future iterations of the MS diagnostic criteria. This exchange illuminates the potential role that OCT can play in the evaluation of the optic nerves in patients with suspected demyelinating disease, even in the absence of ocular symptoms, and also highlights the enduring debate about how optic nerve involvement could be incorporated in the diagnostic criteria for MS. In the article “Optical Coherence Tomography for Detection of Asymptomatic Optic Nerve Lesions in Clinically Isolated Syndrome,” Dr. Outteryck et al. evaluated the ability of intereye retinal thickness difference (IETD) measured by optical coherence tomography (OCT) to detect asymptomatic optic nerve involvement in 130 patients who had presented with clinically isolated syndrome (CIS) within 4.5 months of enrollment. They found that detection of asymptomatic optic nerve lesions in CIS required lower ganglion cell–inner plexiform layer (GC-IPL) IETD thresholds than previously reported and concluded that GC-IPL IETD represents an alternative biomarker to MRI for the detection of such lesions. Although lowering the IETD thresholds may improve the sensitivity of detecting an optic nerve lesion, it comes at the expense of lowering the specificity and this will potentially increase the risk of a false diagnosis of an optic nerve lesion. In response, Dr. Shubhakaran suggests that such a biomarker could help in early intervention to improve the prognosis of patients with multiple sclerosis (MS) and also highlights the utility of OCT in diagnosing macular lesions that may differentiate MS from other disorders. Dr. Shubhakaran notes that OCT is more readily available in certain practice regions than MRI, oligoclonal band testing, and evoked potentials. Responding to these comments, Dr. Outteryck agrees with the utility of OCT in the evaluation of demyelinating diseases, and with the disparate accessibility to OCT and MRI in different parts of the world, but cautions that optic nerve involvement is still not part of the diagnostic criteria for MS for dissemination in space. Noting that optic nerve involvement in patients with CIS is associated with the presence of asymptomatic gadolinium enhancing lesions, Dr. Outteryck argues that optic nerve involvement should be accommodated in future iterations of the MS diagnostic criteria. This exchange illuminates the potential role that OCT can play in the evaluation of the optic nerves in patients with suspected demyelinating disease, even in the absence of ocular symptoms, and also highlights the enduring debate about how optic nerve involvement could be incorporated in the diagnostic criteria for MS.