Damage to the Immature Optic Radiation Causes Severe Reduction of the Retinal Nerve Fiber Layer, Resulting in Predictable Visual Field Defects

PURPOSE The aim of the present study was to seek evidence of a relationship between damage to the optic radiation (OR) in the immature brain and subsequent development of the retinal nerve fiber layer (RNFL) and associated visual manifestations. METHODS Seven cases (2 males and 5 females ranging in age from 18 to 35 years old) were selected from a large cohort of individuals with known white matter damage of immaturity (WMDI), who had presented with visual dysfunction. They underwent magnetic resonance imaging (MRI), including diffusion-weighted MRI. Visual function was evaluated by best-corrected visual acuity and visual field (VF) testing using Goldmann perimetry and Humphrey field analyzer (HFA). RNFL thickness was measured by optical coherence tomography. RESULTS A homogeneous lesion pattern with bilateral WMDI predominantly in the superior posterior periventricular white matter was seen in all subjects. However, as shown by white matter fiber tractography, only cases with injuries to the superior portion of the OR had corresponding inferior VF defects. In the individuals showing structural abnormalities in the OR, a commensurate reduction in the peripapillary RNFL was seen. The RNFL loss was most pronounced in the subjects suffering from the more extensive lesions, and it followed the pattern of OR damage in the sense that damage in the superior portion of the OR gave a reduced RNFL thickness in the superior part of the peripapillary RNFL. CONCLUSIONS Primary injuries in the immature OR are associated with reduced RNFL thickness, and examination of the RNFL may be a helpful predictor of VF defects.