Redistribution within retinal layers of the central fovea in preterms with developmental arrest

Purpose The aim of this study was to characterize thickness changes of foveal layers in preterms with or without signs of immaturity compared to control subjects through analysis of optical coherence tomography (OCT) B‐scan images. Methods Selected eyes from 8 young adults with a history of prematurity (24‐33 weeks of gestation) and 5 controls were imaged using conventional and directional OCT. Retinal layer thickness analysis was performed at selected temporal eccentricities defined by the individual distance between two landmarks for each case, the foveal center (FC) and the foveal rim (R). Results The use of an FC/R landmark transformation enabled comparisons of thickness profiles and area calculations from inter‐individual B‐scans at corresponding landmark positions in both controls and preterms. Reflectometric and manual segmentation measurements showed increased thickness of inner retinal layers (IRL) and photoreceptor cell body and axon/pedicle layers within the central fovea. Thickness and areal differences between controls and preterms with signs of developmental arrest showed a marked redistribution of IRL and the layers of photoreceptor cell bodies, axons and pedicles/synapses within the central fovea. This is in line with incomplete displacement of these layers from the foveal center. Since no changes of photoreceptor inner and outer segment thickness were observed the maturation of the photoreceptor segment layers seems to be within normal limits. Conclusions Our landmark‐based analysis of OCT images using reflectometry and manual segmentation provides complementary findings in comparisons of normal and immature foveal structures. The thickness increase in the outer nuclear, Henle fiber, outer plexiform and post‐receptor layers in preterms with signs of arrested foveal development indicate a marked redistribution of cells.