Intra- and Inter-visit Reproducibility of Ganglion Cell-Inner Plexiform Layer Measurements Using Handheld Optical Coherence Tomography in Children With Optic Pathway Gliomas

PurposeTo determine the intra- and inter-visit reproducibility of ganglion cell-inner plexiform layer thickness measures using handheld optical coherence tomography (OCT) in sedated children with optic pathway gliomas and/or neurofibromatosis type 1 (NF1).DesignProspective longitudinal cohort study.MethodsChildren with sporadic optic pathway gliomas and/or NF1 who had ≥2 volumes acquired over the macula using handheld OCT during sedation for clinically indicated magnetic resonance imaging were eligible for the intra-visit cohort. Children with repeat handheld OCT imaging within 6 months were eligible for the inter-visit cohort. Total retinal thickness and ganglion cell-inner plexiform layer thickness were measured using custom-designed automated segmentation software. Reproducibility was compared across average and anatomic quadrant by calculating the coefficient of variation (CV) and intraclass correlation coefficient (ICC).ResultsForty-two subjects (median age 5.4 years, range 0.8-12.7 years) contributed 45 eyes to the intra-visit cohort. Thirty-one subject eyes had normal vision and 14 had abnormal vision (decreased visual acuity and/or visual field). Average and quadrant ganglion cell-inner plexiform layer measures demonstrated CVs ≤4.5% with excellent ICCs (>0.935). The superior quadrant CV differed between subjects with (4.4%) and without (2.1%) vision loss (P < .05). Twenty-five subject eyes were eligible for the inter-visit cohort, demonstrating CVs from 1.6% to 5.2%. Inter-visit ICCs were excellent (0.955-0.995).DiscussionHandheld OCT imaging in sedated children with optic pathway gliomas produces highly reproducible measures of ganglion cell-inner plexiform layer thickness.