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

PURPOSE

The aim of this study was to assess the incidence of mild (<or=90 degrees) versus severe (>90 degrees 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 degrees , whereas 35% had VFDs >90 degrees postoperatively. Patients in the latter group were reported for suspension of their driver's license. However, 38% experienced improvement of their VFD to <90 degrees such that their driver's license could be reinstated. Of patients with any VFD, 18-30% improved on average by a magnitude of 38 degrees 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 degrees angle) experience some improvement shortly after surgery. This may increase their chances of having their driver's license reinstated.