PROGNOSTIC VALUE OF THE PATTERN ELECTRORETINOGRAM IN CASES OF TUMORS AFFECTING THE OPTIC PATHWAY

Background: Tumors compressing the optic pathway may lead to irreversi ble loss of vision which may be detected by the pattern electroretinog ram (PERG) because of its relation to ganglion cell function. a Method s: Eyes of 19 patients were tested shortly before and 5-10 days after tumor surgery. Visual acuity, the 30-deg visual field and the transien t and steady-state pattern reversal ERG were measured. Results: Using patterns of 1.5x1.2 deg there was a good correlation between the chang e of pre-and post-surgical visual performance and most of the pattern ERG amplitudes. For all variables tested - P50, N95 and steady-state a mplitude - there was a critical value beyond which the visual outcome could be bad or favorable, whereas patients showing higher amplitudes always remained stable or improved after surgery. a Conclusion: The po sitive correlation between pattern ERG amplitudes and the post-surgica l outcome in the case of tumors affecting the optic pathway may be hel pful in predicting the outcome for these patients.