Reversible dysfunction of retinal ganglion cells in non-secreting pituitary tumors.

A large cohort of patients participated in a longitudinal study of early glaucoma progression. During follow up, six eyes of three patients displayed a relatively rapid deterioration of pattern electroretinogram (PERG) signal compared to changes in visual acuity, IOP, Standard Automated Perimetry, and Retinal Nerve Fiber Layer thickness measured by OCT. This deterioration prompted further testing including magnetic resonance imaging (MRI), which revealed pituitary tumors in all three patients, two of which were abutting but not compressing the chiasm. Following tumor resection, the PERG signal gradually recovered to baseline values in all six eyes. Results indicate that pituitary tumors may cause retrograde dysfunction of retinal ganglion cells (RGC) even in the absence of visible mechanical compression of the visual pathway, and such dysfunction may be reversed by tumor reduction. The results suggest that PERG is a useful tool in the early diagnosis and management of patients with chiasmal mass lesions.