Optical coherence tomography in clinically isolated syndrome: no evidence of subclinical retinal axonal loss.

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.

Methods: Prospective case series. Settings Neurologic clinics at the university hospitals of Lille and Strasbourg (France). Methods: Fifty-six consecutive patients with clinically isolated syndrome (18 with optic neuritis and 38 without optic neuritis) and 32 control subjects. Methods: Macular volume and RNFL thickness.

Results: Mean (SD) overall RNFL thickness (98.98 [10.26] microm) and macular volume (6.86 [0.32] microm(3)) in the clinically isolated syndrome population were not significantly different compared with the controls (98.71 [9.08] mum and 6.92 [0.38] microm(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.