Vision Outcomes Following Endoscopic Endonasal Surgery for Lesions Compressing the Optic Apparatus

Introduction: Tumors of the sellar and parasellar region can lead to gradual vision loss. Endonasal endoscopic skull base surgery (ESBS) is often used to approach and remove tumors compressing the optic apparatus. Although visual improvement is generally the goal of surgery in this situation, successful visual improvement is not always achieved. Factors predictive of visual improvement are not well understood.

Methods: A prospectively acquired database of 526 consecutive patients who underwent endoscopic endonasal surgery from 2005-2012 was examined to identify patients with lesions compressing the optic apparatus who had documented preoperative and postoperative visual field examinations and complete volumetric and pre- and postoperative MRI scans. Humphrey visual field tests were reviewed and correlated with clinical course, pathology, approach, tumor volume, extent of resection, and outcome.

Results: Included in the analysis were 108 patients that had complete visual field and tumor volume data sets. The most common presenting vision loss pattern was bitemporal hemianopsia (54% of patients), with the rest comprised of other visual field defects (20%), optic neuropathies (11%), or no defect (15%). Median Humphrey mean deviation preoperatively was −8.95. Operatively, 59% of patients underwent gross total resection (GTR), 14% had near total resection (NTR), and 27% had subtotal resection (STR). Postoperatively, visual acuity improved or remained normal in 71% of patients, remained unchanged in 23% of patients, and worsened in 6% of patients. Median improvement in Humphrey mean deviation was 2.08. Preoperative tumor volume was higher in those patients whose vision worsened (mean tumor volumes were 13.7 cm³, 12.5 cm³, and 19.9 cm³ in patients whose vision improved, remained unchanged, and worsened, respectively), but this difference was not statistically significant (P = 0.35). Additionally, the extent of tumor resected did not correlate with a difference in visual acuity outcomes (P = 0.10). Postoperative complications included 1 CSF leak (0.93%).

Conclusion: Although the majority of patients demonstrate objective improvement in their visual fields after ESBS, it is difficult to predict who will improve based on preoperative tumor volume or extent of resection.