Quantitative Analysis of Changes in Macular Layers Following Optic Neuritis

Abstract

The effects of optic neuritis in patients with multiple sclerosis (MS) on the thickness of individual macular layers was analysed by means of optical coherence tomography (OCT). Data of 15 patients (mean age 37.2 years, range 16–50) with multiple sclerosis and 15 normal subjects (mean age 37.7 years, range 17–67) were analysed. Twelve patients had suffered from an attack of acute unilateral optic neuritis in one or both eyes. OCT scans of the circumpapillary retinal nerve fibre layer (RNFL) and of the macula were obtained by means of fast scan protocols. The characteristic sequence of five intensity maxima and four intensity minima was attributed to the mean location of the individual macular layers. The eyes affected by optic neuritis showed significant (p < 0.05) reductions of RNFL thickness by 30.5%, of macular volume (MV) by 12.8%, and of inner macular layers. The mean reduction was 16.2% (macular nerve fibre layer), 31.1% (ganglion cell layer [GCL]), and 25.9% (inner plexiform layer [IPL]), respectively. However, significant reductions of RNFL thickness (by 9.0%), MV (by 5.0%), CGL (by 10.3%), and IPL (by 10.8%) were found also in the unaffected eyes of MS patients. Thus, the quantitative analysis of the axial reflectivity profiles from exported OCT images offers an appropriate method for the characterisation of the location of macular changes after optic neuritis. The shrinking of inner macular layers is a more sensitive parameter of postneuritic optic atrophies than the reduction of MV.

Keywords::

• macular layers
• multiple sclerosis
• optic neuritis
• optical coherence tomography
• retinal nerve fibre layer

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.