Losses of hemifield contrast sensitivity in patients with pituitary adenoma and normal visual acuity and visual field

Objective: To detect early losses of contrast sensitivity (CS) in patients with pituitary adenomas, before the occurrence of visual acuity and visual field defects. Methods: CS has been evaluated in both hemifields of 28 patients with diffe rent kinds of pituitary adenoma (mainly intrasellar) and normal visual acui ty and visual held, as well as in 15 age-matched controls. Two different st imuli were used: a coarse (0.3 c/deg) dynamic (10 Hz) grating and a finer ( 2 c/deg) static grating. Results: On average, CS and/or hemifield asymmetry were reduced in patients , whereas perimetric sensitivity was normal. CS losses were more frequent f or 2 c/deg static-, as compared with 0.3 c/deg. 10 Hz stimuli. However sele ctive losses for either stimuli were also found. CS losses did not correlat e with anatomical measurements (size, chiasm involvement) of tumors as esta blished by MRI scans. Conclusions: CS evaluation may provide a simple and effective tool for earl y detection and monitoring of visual dysfunction in patients with pituitary adenoma. The lack of correlation between CS losses and chiasm involvement suggests causes different from chiasmal compression for visual dysfunction. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.