Intra- and inter-visit reproducibility of ganglion cell-inner plexiform layer measurements using handheld optical coherence tomography in children with optic pathway gliomas

Purpose: To 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).

Design: Prospective longitudinal cohort study.

Methods: Children with sporadic optic pathway gliomas and/or NF1 who had ≥2 volumes acquired over the macula using handheldOCT during sedation for clinically indicated magnetic resonance imaging were eligible for the intra-visit cohort.Children with repeat handheldOCT imagingwithin 6monthswere 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).

Results: Forty-two subjects (median age 5.4 years, range 0.8-12.7 years) contributed 45 eyes to the intravisit 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).

Discussion: Handheld OCT imaging in sedated children with optic pathway gliomas produces highly reproducible measures of ganglion cell-inner plexiform layer thickness.