Retinal Nerve Fiber Layer Measurements and Optic Nerve Head Analysis in Multiple Sclerosis Patients

Abstract

Purpose:: To verify whether scanning laser polarimeter with the new variable corneal compensation algorithm (GDx VCC) and scanning laser ophthalmoscopy (Heidelberg Retina Tomograph (HRT)) allow measuring retinal ganglion cell loss in patients with multiple sclerosis (MS).

Methods:: We enrolled 23 MS patients with an history of previous demyelinating monocular optic neuritis. Examination included visual evoked potentials (VEPs), scanning laser ophthalmoscopy and scanning laser polarimeter. HRT was performed to assess optic nerve head shape, while GDx VCC was used to evaluate the retinal nerve fiber layer thickness (RNFLt) around the optic nerve head (ONH). Statistical analysis was performed comparing results obtained for each eye with the available normative database and with the unaffected fellow-eye.

Results:: When the affected eye group was compared to the fellow-eye group, a significant (p<0.05) difference was found for some GDx VCC parameters and for mean RNFLt of HRT. In contrast, no significant correlation was observed between clinical assessment and imaging techniques when the normal database of HRT and GDx VCC was used. A significant association was observed between VEP latency and some GDx VCC parameters, while HRT parameters and VEP values did not show a significant correlation.

Conclusions:: Our results suggest that, at variance with HRT, scanning laser polarimetry can detect loss of ganglion cells following demyelinating optic neuritis and may be considered as useful tool to measure axonal damage in MS patients.

Keywords: optic disc • nerve fiber layer • neuro-ophthalmology: optic nerve