Visual acuity in patients with non-functioning pituitary adenoma: Prognostic factors and long-term outcome after surgery.

Background: Visual acuity (VA) and visual field defects (VF) are evaluated in the preoperative management of non-functioning pituitary adenoma (NFPA). The former is less studied than the latter. Research question: To analyze preoperative factors, including adenoma volumetry, associated with reduced VA and postoperative improvement of VA over five years after surgery. Methods: Eighty-seven patients who had primary surgery for NFPA were retrospectively reviewed. Eyes were categorized by best/worse preoperative VA. Ophthalmology review was performed before surgery, at three months, one to two years, and five years post-surgery. Results: Reduced VA in any eye was present in 55%. VA of the worse eye improved in 77% and normalized in 54%. The majority improved within three months. Additional cases with VA improvement were seen at 1-2 years after surgery. No further improvement was seen five years after surgery. Fifty percent of patients with, per definition, normal preoperative VA showed improved VA postoperatively. Tumor height above the sella in the sagittal plane was the best radiological predictor of reduced VA. Volumetry did not add to accuracy. Age, sagittal tumor height and visual field defects were risk factors of preoperative reduced VA. No predictors of postoperative recovery were identified. Conclusion: Half of patients with reduced VA recover fully. All patients, independent of age and degree of VA reduction, may improve. No predictors of recovery were found. Early improvement is common and improvement beyond two years is unlikely. The frequency of reduced VA is underestimated. The present results could be of value in pre- and postoperative counseling.