Optical Coherence Tomography of the Macular Ganglion Cell Complex Demonstrating Transsynaptic Retrograde Degeneration from a Temporal Lobe Tumor: A Case Report

Abstract

We report a 39-year-old male who had generalized tonic-clonic seizure with loss of awareness. Investigations led to a diagnosis of a left temporal lobe tumor. He underwent resection of the mass with consequent loss of brain tissue in the temporal lobe and was found to have a complete right homonymous hemianopia in the immediate postoperative period. Macular ganglion cell analysis on optical coherence tomography (OCT) showed homonymous thinning affecting the inferonasal sector in the right eye and inferotemporal sector in the left eye. This case demonstrates transsynaptic retrograde degeneration through the interruption of the inferior optic radiation, and its corresponding effect on the structure and function of the affected retinal field. Temporal lobe lesions may cause not only a homonymous visual f ield defect contralateral to the side of the lesion but also result to homonymous sectoral thinning of the macular ganglion cell complexes in both eyes located ipsilateral to the side of the lesion.