Trans-Synaptic Retrograde Degeneration of the Retinal Nerve Fiber Layer and Retinal Ganglion Cell After Posterior Cerebral Artery Infarction

Purpose: To investigate long-term changes in retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL) thickness in patients with posterior cerebral artery (PCA) infarction and homonymous visual field defects. Methods: This retrospective study included patients with PCA infarction and homonymous visual field defects with a minimum follow-up of 6 months. Retinal thinning was defined as a ≥10% decrease from baseline to the final follow-up examination. Affected and non-affected sectors of the RNFL and GC-IPL were defined according to the retinotopic pattern of the homonymous visual field defect. The incidence of retinal thinning, retinal thickness changes, and time to retinal thinning were analyzed in the ipsilateral and contralateral eyes relative to the brain lesion. Results: Of 142 screened patients, 29 30 were included. The incidence of thinning in affected sectors was 13.8% for the RNFL and 31.0% for the GC-IPL. The thinning ratio of GC-IPL was higher in affected sectors than in non-affected sectors (p = 0.008), whereas that of the RNFL was not significant (p = 0.983). The median time to thinning in affected sectors was 12.0 months for the RNFL and 18.0 months for the GC-IPL. Significant GC-IPL thinning was observed in the inferotemporal, inferior and superotemporal sectors of ipsilateral eyes, and in the inferonasal, superonasal, inferior, and superior sectors of contralateral eyes. Conclusions: Trans-synaptic retrograde degeneration TRD was observed after PCA infarction, with the incidence of 13.8% for RNFL thinning and 31.0% for GC-IPL thinning. The median time to GC-IPL thinning was 18.0 months during long-term follow-up. These findings suggest that long-term ophthalmic follow-up may be important for detecting chronic structural changes after post-geniculate visual pathway injury.