Using Ganglion Cell Analysis in differentiating glaucoma from glaucoma-mimickers

Abstract

Background: Imaging modalities provide a number of unique opportunities in assessing patients with ocular and visual system disease. One aspect not fully appreciated is the use of OCT retinal segmentation analysis to help discriminate glaucoma from conditions that may mimic glaucoma. We report on a number of cases where careful assessment of imaging results helps differentiate glaucoma-like retinal retrograde neuronal degeneration due to cortical lesions.

Case reports: A 37 year old male with VA of 20/20 presented for a glaucoma assessment. He had been told that his optic nerves were ‘suspicious’ and required regular reviews. Visual acuity was 20/20 OU, IOP 15 OU, no RAPD. No systemic conditions, no history of trauma and upon questioning he advised us that he had meningitis when 2 weeks old. The optic nerve head changes were consistent with subtle neuropathy with a nerve fiber layer deficit indicate of major loss (consistent with glaucomatous-like changes). The discriminant OCT imaging modality was provided by the ganglion cell analysis that displayed a congruous deficits in both eyes, corresponding to the congruous inferior quadrantanopia. A CT scan showing the cortical lesion, likely due to the meningitis, confirmed the location. A number of other clinical cases will also be presented showing the usefulness of careful review of the ganglion cell analysis in helping the clinical discrimination of primary optic nerve neuropathy to that produced by retrograde degeneration.

Conclusions: Although it is commonly taught that cortical lesions do not cause retinal/optic nerve changes, a number of recent clinical reports have provided clear evidence that retrograde retinal degeneration is present secondary to cortical lesions. We provide a number of clinical cases where retinal imaging results exquisitely correspond to visual field loss consistent with retrograde degeneration. A number of clinical pearls will be outlined in the presentation.