Study Evaluates Ganglion Cell Layer Thickness in Patients With Pituitary Adenoma

Measuring ganglion cell layer can be useful in detecting both preperimetric and progressive disease in people with pituitary lesions, according to research presented at the North American Neuro-Ophthalmology Society (NANOS) 2021 Annual Meeting, held virtually February 20 to 23, 2021. 

In a retrospective cross-sectional analysis, researchers set out to evaluate ganglion cell layer thickness via optical coherence tomography (OCT) in a population of patients with pituitary adenoma with and without visual symptoms. Included patients presented with chiasmal compression on neuroimaging and had no other underlying optic neuropathies or retinal damage. 

Investigators used OCT measurements as a surrogate indicator for optic nerve integrity and per researchers, ganglion cell layer thickness was indicative of compressive neuropathy. Segmentation was used to analyze individual retinal layers, and data were generated for mean ganglion cell layer thickness in macular sectors centered on the fovea in 1 mm, 3 mm, and 6 mm rings. 

Investigators used a Mann Whitney U-test for non-parametric data to analyze the study population against normative population data. A Wilcoxon signed rank test was also used to analyze ganglion cell layer thickness between the nasal and temporal sectors. 

The study cohort included 28 eyes (mean age, 52 years; range, 22 years to 89 years). When compared with population-level data, patients in the study cohort had lower mean ganglion cell layer thickness values in the inner nasal sectors (P =.004). Further analysis indicated, within the population-level data, lower ganglion cell layer values in the combined nasal and temporal sectors (P <.0001). Conversely, no similar difference was found in the study cohort. 

“This study revealed [that ganglion cell layer] thinning is confined to the inner nasal [in optical coherence tomography] sectors in patients with pituitary adenoma,” the research says. “There is growing consensus that [ganglion cell layer] analysis should be routinely incorporated into the evaluation of patients with chiasmal lesions.” 

“Analysis of [ganglion cell layer] parameters provide a useful tool for monitoring patients with compressive optic neuropathies, both through baseline and serial measurements It is also invaluable in detecting pre-perimetric and progressive disease prior to the development of irreversible visual loss. Data from this study, together with previously published reports, supports the use of [ganglion cell layer] measurements in neuro-ophthalmic evaluation of patients with chiasmal lesions.” 

Reference

Bhardwwaj P, Kasbekar S, Gruener AM. Ganglion cell layer thickness is reduced in inner nasal sectors in patients with pituitary adenoma. Presented at: North American Neuro-Ophthalmology Society 2021 Annual Meeting; February 20-23, 2021; Poster 85.