ELECTROPHYSIOLOGICAL AND PSYCHOPHYSICAL EXAMINATION IN PATIENTS WITH OPTIC-NERVE COMPRESSION

Citation
B. Sadowski et al., ELECTROPHYSIOLOGICAL AND PSYCHOPHYSICAL EXAMINATION IN PATIENTS WITH OPTIC-NERVE COMPRESSION, Neuro-ophthalmology, 15(5), 1995, pp. 223-231
Citations number
37
Categorie Soggetti
Ophthalmology,Neurosciences
Journal title
Neuro-ophthalmology
ISSN journal
01658107 → ACNP
Volume
15
Issue
5
Year of publication
1995
Pages
223 - 231
Database
ISI
SICI code
0165-8107(1995)15:5<223:EAPEIP>2.0.ZU;2-P
Abstract
Compression of the optic nerve causes a descending degeneration of opt ic nerve fibers. Additionally to the clinical symptoms (loss of visual acuity, scotomas), electrophysiological methods can be used to evalua te the function of the optic nerve (VEP) and the retinal ganglion cell layer (pattern ERG, PERG). In order to investigate the prognostic sig nificance of electrophysiological methods for postoperative recovery o f visual function, II patients (22 eyes) suffering from compression of the optic nerve or chiasm due to pituitary tumors or meningiomas were investigated prior to and after surgical decompression. Visual acuity and perimetry were compared to preoperatively performed transient pat tern VEP and transient PERG (N-(95) amplitude). Prior to surgery, the patients suffered from impairment of visual acuity and scotomas. After surgical decompression, visual acuity improved in seven eyes, remaine d unchanged in II eyes and deteriorated in four eyes. Visual field def ects improved in I3 eyes, one visual held deteriorated. In all patient s preoperative VEP examination revealed pathological findings (half an d Ganzfeld). Latency of half field VEPs was prolonged in five eyes in which the corresponding visual fields were normal. The N-95 of the PER G was also pathological in three eyes, which postoperatively did not r eveal any improvement in visual fields. The results demonstrate that V EP latency can be more sensitive than the PERG in the diagnosis of com pression with subsequent descending degeneration of the optic nerve. P athological latencies when stimulating with half field VEPs can indica te a first subclinical damage of the optic nerve prior to psychophysic al and morphological findings. Pathological PERGs prior to decompressi on seem to indicate a poor prognosis concerning the improvement of psy chophysical function after surgery.