Abstract
Purpose:
Chiasmal compression predominantly affects the crossing nerve fibers and inner retinal layer in the nasal hemiretina and shows band atrophy (BA) of the optic nerve head. The purpose of this study was to assess the diagnostic performance in macular parameters by spectral domain-optical coherence tomography (SD-OCT) for detection of BA.
Methods:
In this study, 49 BA eyes with permanent temporal hemianopia, 89 normal eyes were enrolled. Any patients had nasal visual field loss were excluded. Each participant was imaged by 3D OCT-2000 (Topcon Inc.) and 10×10 grids were automatically divided from the macular analysis. The retinal nerve fiber layer (RNFL), ganglion cell layer (GCL)+ (GCL+inner plexiform layer (IPL)), and GCL++ thickness (RNFL+GCL+IPL) in both nasal and temporal hemiretina were calculated and compared between BA and normal groups. The areas under the receiver operating characteristic curves (AUCs) in these parameters were compared between the nasal hemiretina and temporal hemiretina by bootstrap and Pepe’s method
Results:
All parameters in BA eyes were significantly thinner than those in normal eyes. The AUCs for the RNFL, GCL+, and GCL++ thickness in the nasal hemiretina were 0.890, 0.988 and 0.981, respectively. The AUCs for the RNFL, GCL+, and GCL++ thickness in the temporal hemiretina were 0.619, 0.789 and 0.768, respectively. The nasal parameters showed significantly higher AUCs than those parameters in the temporal hemiretina. Also, GCL+ thickness displayed significant higher AUC than RNFL in the nasal hemiretina (p<0.001)The inner retinal parameters at macular in the nasal hemiretina exhibited high abilities for diagnosing BA. GCL+ was more affected than RNFL in nasal hemiretina. Unexpectedly, thinning of inner retinal layer in the temporal hemiretina was exhibited. The uncrossing nerve fibers at chiasma might be damaged in subclinical degree or median strip of overlap at fovea might be involved.
Conclusions:
The inner retinal parameters at macular in the nasal hemiretina exhibited high abilities for diagnosing BA. GCL+ was more affected than RNFL in nasal hemiretina. Unexpectedly, thinning of inner retinal layer in the temporal hemiretina was exhibited. The uncrossing nerve fibers at chiasma might be damaged in subclinical degree or median strip of overlap at fovea might be involved.
Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
612 neuro-ophthalmology: diagnosis