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 different kinds of pituitary adenoma (mainly intrasellar) and normal visual acuity and visual field, as well as in 15 age-matched controls. Two different stimuli were used: a coarse (0.

Spatial-temporal interactions in the steady-state pattern electroretinogram.

It is currently assumed that steady-state pattern electroretinograms can be obtained only at high rates of pattern reversal. However, steady-state responses can also be obtained at very low temporal frequencies (less than 1 Hz), provided that the reversal is sinusoidal. In five healthy volunteers, we studied the frequency characteristics of the pattern-reversal electroretinogram in response to sinusoidal gratings of 0.