Optical Coherence Tomography in Clinically Isolated Syndrome

Abstract

Background: Optical coherence tomography has emerged as a new tool for quantifying axonal loss in multiple sclerosis (MS). A reduction in retinal nerve fiber layer (RNFL) thickness is correlated with Expanded Disability Status Scale score and brain atrophy. Objective: To investigate RNFL and macular volume measurements using optical coherence tomography in the clinically isolated syndrome population. Design: Prospective case series. Settings: Neurologic clinics at the university hospitals of Lille and Strasbourg (France). Participants: Fifty-six consecutive patients with clinically isolated syndrome (18 with optic neuritis and 38 without optic neuritis) and 32 control subjects. Main Outcome Measures: Macular volume and RNFL thickness. Results: Mean (SD) overall RNFL thickness (98.98 [10.26] µm) and macular volume (6.86 [0.32] µm 3) in the clinically isolated syndrome population were not significantly different compared with the controls (98.71 [9.08] µm and 6.92 [0.38] µm 3 , respectively). No link was noted between atrophy of the RNFL or macula and conversion to MS at 6 months. Conclusions: Optical coherence tomography does not reveal retinal axonal loss at the earliest clinical stage of MS and does not predict conversion to MS at 6 months.

Evaluating the Use of Optical Coherence Tomography in Optic Neuritis

“…In this prospective case series, there was no link between RNFL and (1) MRI evidence of disseminated CNS inflammation at baseline, (2) disseminated CNS inflammation according to the revised McDonald criteria, (3) gadolinium enhancement on initial MRI, (4) multifocal CIS presentation, (5) altered visual evoked potentials, or (6) development of “McDonald-” proven MS at 6 months [31]. Furthermore, patients who developed CDMS ( n = 13) or McDonald-criteria proven MS ( n = 23) did not have more severe RNFL atrophy [31]. These investigators concluded that OCT does not predict conversion to MS at 6 months in CIS patients and postulated that conversion to MS after ON is more likely influenced by inflammatory events than axonal degeneration.…”

“…Only two prior studies have explored the association between RNFL atrophy and future risk of MS in ON patients, and the data were largely negative [18, 31]. Previously, we compared RNFL values in ON eyes and non-ON eyes between patients who developed CDMS (42%) and those that did not develop MS 24 months after an ON event (58%) [18].…”

“…Similarly, Outteryck and colleagues [31] performed OCT testing on 56 CIS patients (18 with optic neuritis and 38 without optic neuritis) and 32 control subjects, to investigate whether measures of RNFL thickness and macular volume revealed early retinal axonal loss. In this prospective case series, there was no link between RNFL and (1) MRI evidence of disseminated CNS inflammation at baseline, (2) disseminated CNS inflammation according to the revised McDonald criteria, (3) gadolinium enhancement on initial MRI, (4) multifocal CIS presentation, (5) altered visual evoked potentials, or (6) development of “McDonald-” proven MS at 6 months [31]. Furthermore, patients who developed CDMS ( n = 13) or McDonald-criteria proven MS ( n = 23) did not have more severe RNFL atrophy [31].…”

Exploring the Association between Retinal Nerve Fiber Layer Thickness and Initial Magnetic Resonance Imaging Findings in Patients with Acute Optic Neuritis

“…Only two prior reports have explored whether OCT-measured RNFL values distinguish patients at future risk of CDMS after ON, and in both studies the results were predominantly negative [31, 32] Previously, we compared RNFL values in ON eyes and non-ON eyes between patients who developed CDMS (42%) and those that did not develop MS within a minimum of 24 months after an acute ON event (58%), in the same patient cohort. [31] Mean RNFL values were reduced in ON eyes of non-MS patients as compared to CDMS ON eyes after one year ( P = .05) due to more severe ON events in the former [31].…”

Optical Coherence Tomography - A New Monitoring Tool for Multiple Sclerosis?

“…47 In patients with CIS who had no history of ON, our group in Lille failed to find significant differences in RNLF thickness, and changes did not increase the risk of conversion to MS after a sixmonth period of follow-up. 48 However, our analysis was not performed using the latest technical methods. Since RNLF thickness may be associated with the degenerative component of MS, OCT measurements and atrophy of the brain, assessed using the brain parenchymal fraction (BPF), were compared.…”