Retinal microstructures are altered in patients with idiopathic infantile nystagmus

Purpose To compare segmented retinal layer thicknesses between patients with idiopathic infantile nystagmus (IIN) and controls. Methods This retrospective case-control study included 66 patients with IIN and 66 age-matched controls. The retinal layers were examined using spectral domain optical coherence tomography with autosegmentation. Central foveal thickness (CFT), outer nuclear layer (ONL), and outer segment length (OSL) thickness were measured at the fovea center. Mean values for retinal nerve fiber layer, ganglion cell inner plexiform layer (GCIPL), inner nuclear layer, outer plexiform-outer nuclear layer (OPNL) thicknesses were calculated at two measurement points (nasal and temporal hump points at the macula area). Results There were no significant between-group differences in age, gender, or refraction error. The CFT was thicker in the IIN group compared with the control group (225.0 mu m vs. 217.8 mu m, P = 0.017) and OSL was shorter in IIN than in controls (40.0 mu m vs. 43.7 mu m., P < 0.001). The ONL thickness at the central fovea was not statistically different between the two groups. At the nasal and temporal position where the ganglion cell density was thickest, the GCIPL thickness was thinner in the IIN group compared to the controls (99.5 mu m vs. 102.8 mu m, P = 0.010). The GCIPL thickness was negatively correlated with logMAR visual acuity (Spearman's rho = -0.502, P < 0.001). Conclusions The foveal pit was shallower, OSL was shorter, and the GCIPL thicknesses at macular humps were decreased in the patients with IIN compared with that of controls. The faulty development of the macula may be related to unknown pathophysiologic mechanism during fovea maturation in IIN or continuous eye movement itself interrupt fovea development.