Stages of improvement in visual fields after pituitary tumor resection

PURPOSE: To use static threshold perimetry to examine the stages of improve ment and the potential for late improvement of visual fields after surgical resection of pituitary adenomas causing visual loss from compression of th e anterior visual pathways. METHODS: Retrospective review of charts of patients with pituitary tumors a nd abnormal static threshold perimetry before or soon after treatment who h ad subsequent visual fields. Quantification of the visual field mean deviat ion overall, superotemporally, and inferotemporally was performed and compa red between visits. Postoperative visits were considered in five time perio ds: visit 1 (surgery to 1 week), visit 2 (1 month to 4 months), visit 3 (6 months to 1 year), visit 4 (2 years), and visit 5 (3 or more years). RESULTS: Sixty-two patients were included (33 men and 29 women; mean age 54 years [SD +/- 15 years; range, 22 to 83 years]), At visit 1, the relative improvement of the overall mean deviation for the right eye was 30.8% (P = .01) and for the left eye was 13.7% (P = 3067). At visit 2, the relative im provement of the overall mean deviation for the right eye was 30.4% (P = .0 142) and for the left eye was 32.6% (P = .0092), At visits 1 and 2, the inf erotemporal quadrants were the quadrants with greatest improvement (visit 1 , right eye, 37.8% [P = .0082]; visit 2, left eye, 30.8% [P = .0074]), At v isits 3, 4, and 5, an overall trend toward mild improvement was observed wi th statistical significance only for the inferotemporal quadrant of the lef t eye from visit 2 to visit 3, which improved 19.7% (P = .0270). CONCLUSION: The pattern of recovery of visual function after decompression of the anterior visual pathways suggests at least three phases of improveme nt, The early fast phase (surgery to 1 week) of improvement may lead to nor malization of visual fields in some individuals. The early slow phase (1 mo nth to 4 months) is the period of most notable improvement. A late phase (6 months to 3 years) of mild improvement does not appear significant overall but may be marked in some individuals. Each of these phases may have one o r more mechanisms underlying the observed improvement. (C) 2000 by Elsevier Science Inc. All rights reserved.