Dynamics of visual improvement following chiasmal decompression. Quantitative pre- and postoperative observations.
OBJECTIVE
To study early visual restoration following surgical removal of pituitary adenomas compressing the optic chiasm.


METHODS
Eleven patients were examined with high-pass resolution perimetry (HRP) before and after trans-sphenoidal adenomectomy. Visual fields were examined on the second postoperative day. The result was interpreted in terms of the estimated fraction of functioning retino-cortical connections.


RESULTS
In the upper and lower temporal visual field quadrants, the mean increases in the fraction of functioning neural channels were 19% (p < 0.001) and 17% (p = 0.001), respectively, on day 2 after surgery. These increased to 35% on day 12. The nasal hemifield showed no change on day 2, but functioning neural channels had increased by 15% on day 5 (p = 0.017). Mean visual acuity improved from 0.6 preoperatively to 1.0 on day 2 (p = 0.030) but did not change significantly thereafter.


CONCLUSIONS
All visual field sectors and visual acuity improved after surgery. Improvement starting in the temporal hemifield was already evident on the second postoperative day.
Jakobsson
Karl-Erik
KE
Section of Neurological Diseases, Institute of Clinical Neuroscience, The Sahlgrenska Academy at Gothenburg University, Sweden.
Petruson
Björn
B
Lindblom
Bertil
B
D000236:Adenoma / Q000150:complications / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000209:etiology / Q000503:physiopathology*; D009897:Optic Chiasm / Q000503:physiopathology*; D009901:Optic Nerve Diseases / Q000209:etiology / Q000503:physiopathology*; D010911:Pituitary Neoplasms / Q000150:complications / Q000473:pathology / Q000601:surgery*; D011184:Postoperative Period; D014792:Visual Acuity / Q000502:physiology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology