Nerve fiber layer and macular thinning measured with different imaging methods during the course of acute optic neuritis

PURPOSE. To compare retinal nerve fiber layer thickness (RNFLT) and inner macula thickness changes measured with Fourier domain optical coherence tomography (FD-OCT) and scanning laser polarimetry during the course of acute optic neuritis (ON). METHODS. Nine eyes of 7 consecutive patients with multiple sclerosis (MS) were prospectively imaged from the onset of ON for 6 to 12 months. Nine healthy eyes were imaged for 12 to 19 months. RESULTS. Retinal nerve fiber layer thickness measured with FD-OCT initially increased in all eyes with diffuse optic disc edema. Inner macula thickness and polarimetric RNFLT decreased already in the acute phase, in all eyes. All parameters stabilized at 2 to 5 months. The relative structural loss was different with the different methods. Poor image quality with polarimetry occurred in 2 eyes in the acute phase of ON. In the control eyes all parameters were stable. CONCLUSIONS. Change of RNFLT and macular thickness during the course of acute ON in MS strongly depends on the method used for the measurement. Inner macula thickness, measured with FD-OCT was especially useful for the follow-up, since it was not influenced by initial disc edema and had consistently high image quality.