Purpose: To evaluate the reliability of the spectral domain handheld OCT (HH-OCT) in assessing foveal morphology in children with and without nystagmus.
Methods: Forty-nine subjects with nystagmus (mean age 43.83 months; range, 1-82 months) and 48 controls (mean age 43.02 months; range, 0 to 83 months) were recruited and scanned using HH-OCT. A minimum of two separate volumetric scans on the same examination day of the fovea were obtained. The images were imported into ImageJ software where manual retinal layer segmentation of the central foveal B-scan was performed. Agreement between scans was assessed by determining the intraclass correlation coefficients (ICC) and Bland-Altman plots.
Results: Both the nystagmus and control groups showed an excellent degree of reproducibility between two examinations with ICCs greater than 0.96 for central macular thickness (CMT) and greater than 0.8 for the outer nuclear layer and outer segment of the photoreceptors. The nerve fiber layer, ganglion cell layer, outer plexiform layer, inner segment of the photoreceptors, and retinal pigment epithelium were less reliable with ICCs of less than 0.7. There was no difference in the reliability of scans obtained in children with nystagmus as compared with controls and both groups had good intereye agreement with ICCs greater than 0.94 for CMT.
Conclusions: We have shown for the first time that the HH-OCT provides reliable measurements in children with and without nystagmus. This is important, as the HH-OCT will have a greater diagnostic and prognostic role in young children with nystagmus and other eye diseases in the future.
Keywords: children; congenital nystagmus; fovea; optical coherence tomography; reliability.