[Postoperative recovery of visual function in sella tumors: prognostic assessment by electro-ophthalmologic studies]

Preoperative examination of the visual system in patients with tumors of the sellar region is usually limited to checking the visual acuity, assessing the visual field, and ophthalmoscopy of the optic disc. In addition to these tests we investigated pre- and postoperatively 35 patients with meningiomas, pituitary adenomas and other sellar and parasellar tumors by recording the pattern electroretinogram (PERG) and the pattern-evoked cortical potential (PVECP) in order to evaluate functional and possible structural impairment of the visual pathway. Based on electro-ophthalmological tests, the retinal and cortical findings were classified as: regular ERG and VECP (0), regular ERG and irregular VECP (1), irregular ERG and VECP (2). Up to six months postoperatively, eyes with alteration of the VECP alone (category 1) showed recovery of visual function, while those with alteration of ERG as well (category 2) did not recover in visual function. Since loss of the PERG or long-lasting alteration of it is indicative of irreversible impairment of the inner retinal layers including the retinal ganglion cells, repeat examination of the pattern ERG is recommended in disturbances caused by alterations in the central nervous system.