Ganglion Cell Layer-Inner Plexiform Layer Thickness and Vision Loss in Young Children With Optic Pathway Gliomas

PURPOSE. To determine if measures of macular ganglion cell layer-inner plexiform layer (GCL-IPL) thickness can discriminate between children with and without vision loss (visual acuity or field) from their optic pathway glioma (OPG) using spectral-domain optical coherence tomography (SD-OCT). METHODS. Children with OPGs (sporadic or secondary to neurofibromatosis type 1) enrolled in a prospective study of SD-OCT were included if they were cooperative for vision testing and macular SD-OCT images were acquired. Manual segmentation of the macular GCL-IPL and macular retinal nerve fiber layer (RNFL) was performed using elliptical annuli with diameters of 1.5, 3.0, and 4.5 mm. Logistic regression assessed the ability of GCL-IPL and RNFL thickness measures (micrometers) to differentiate between the normal and abnormal vision groups. RESULTS. Forty-seven study eyes (normal vision = 31, abnormal vision = 16) from 26 children with OPGs were included. Median age was 5.3 years (range, 2.5-12.8). Thickness of all GCL-IPL and RNFL quadrants differed between the normal and abnormal vision groups (P < 0.01). All GCL-IPL measures demonstrated excellent discrimination between groups (area under the curve [AUC] > 0.90 for all diameters). Using the lower fifth percentile threshold, the number of abnormal GCL-IPL inner macula (3.0 mm) quadrants achieved the highest AUC (0.989) and was greater than the macula RNFL AUCs (P < 0.05). CONCLUSIONS. Decreased GCL-IPL thickness (< fifth percentile) can discriminate between children with and without vision loss from their OPG. Ganglion cell layer-inner plexiform layer thickness could be used as a surrogate marker of vision in children with OPGs.