Optical coherence tomography analysis of inner and outer retinal layers in eyes with chiasmal compression caused by suprasellar tumours.

Abstract

To compare postoperative macular thickness measurements of inner and outer retinal layers in eyes of patients with chiasmal compression with or without visual field (VF) recovery and healthy controls using optical coherence tomography (OCT). Macular spectral-domain OCT has been used for the auto-segmentation of images obtained from 100 eyes affected with chiasmal compression compared with 100 healthy controls enrolled in this study. We have divided eyes with chiasmal compression into two groups: group 1 characterized by VF recovery after tumour excision and group 2 showing partial or no recovery of VF. The thickness of the macular retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor layer (PRL), inner retinal layer (IRL) and outer retinal layer (ORL) was segmented. The correlation between macular RNFL (mRNFL) and functional parameters has been analysed. Both groups 1 and 2 showed significant thinning of RNFL, GCL, IPL and IRL in all quadrants. However, no significant changes have been detected in PRL and ORL of patients in either group compared with healthy controls. A significant thickening was detected in INL and ONL of group 2 compared with healthy controls and group 1. Postoperative mRNFL thickness is significantly correlated with VF defects and visual acuity except temporal quadrant. Eyes with chiasmal compression showed thinning of the inner retinal layers with thickening of the INL and ONL in patients with partial to no recovery of VF. The changes in retinal microstructures are well-correlated with functional recovery. Further studies are needed to reveal the clinical implications of these findings in patients with chiasmal compression.