Visual field deficits following anterior temporal lobectomy: Long-term follow-up and prognostic implications

Abstract

Purpose: The aim of this study was to assess the incidence of mild (≤90°) versus severe (>90° from vertical) visual field defects (VFDs) in patients after anterior temporal lobectomy (ATL), and their postoperative improvement over time. Methods: The angles of postoperative VFDs of 75 patients who underwent ATL were recorded at various time points (1, 2, 6, 12, 18, 24, and 36+ months). Results: Of all 23 patients who came in for their <1 month postoperative appointment, 65% of patients had surgically induced VFDs <90°, whereas 35% had VFDs >90° postoperatively. Patients in the latter group were reported for suspension of their driver's license. However, 38% experienced improvement of their VFD to <90° such that their driver's license could be reinstated. Of patients with any VFD, 18-30% improved on average by a magnitude of 38° within the first year postoperatively. Discussion: Although 35% of the VFDs that occur following temporal lobe surgery are severe, approximately 38% of these patients (especially those with starting postoperative VFDs closer to the 90° angle) experience some improvement shortly after surgery. This may increase their chances of having their driver's license reinstated. © 2010 International League Against Epilepsy.