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

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.

To investigate RNFL and macular volume measurements using optical coherence tomography in the clinically isolated syndrome population.

Prospective case series. Settings Neurologic clinics at the university hospitals of Lille and Strasbourg (France).

Fifty-six consecutive patients with clinically isolated syndrome (18 with optic neuritis and 38 without optic neuritis) and 32 control subjects.

Macular volume and RNFL thickness.

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.

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.