Objective: To analyze the time-dependent characteristics and possible prognostic factors for postoperative visual field improvement in patients after undergoing endonasal transsphenoidal pituitary tumor resection surgery. Methods: This retrospective case series study included 110 patients (212 eyes) who with visual
field defect underwent endonasal transsphenoidal pituitary tumor resection at the Fifth People's Hospital of Shanghai Fudan University between January 2013 and February 2016. Preoperative scans of the pituitary Time-Dependent Characteristics and Prognostic Factors of Visual Field Improvement in Patients after Endonasal Transsphenoidal Pituitary Tumor Resection were made by computed tomography or magnetic imaging resonsance. Preoperative eye examinations
included visual acuity, refraction, slit-lamp examination, fundus examination, intraocular pressure measurement, and central static visual field perimetry with a Humphrey-750i perimeter. Visual fields were measured again 1 week after surgery. Thirty patients (45 eyes) with visual field improvement and complete 3, 6, and 12 months follow-up data were analyzed for visual field improvement tendency. The mean deviation (MD) was used to quantify the visual field defect. Univariate analysis and multivariate logistic regression analysis for the prognostic factors of postoperative visual field improvement were carried out with SPSS 24.0 statistical software. Results: In the 30 patients with complete follow-up data, there was significant improvement in the postoperative visual field at 1 week after surgery, but the rate of improvement gradually declined over time. One patient experienced a pituitary tumor recurrence 12 months after surgery.There were significant differences in preoperative best corrected visual acuities (F=17.025, P < 0.001),preoperative MD absolute values (F=37.580, P < 0.001), preoperative full superotemporal quadrant visual field defects (χ2=17.459, P < 0.001), optic chiasm compressions (χ2=11.296, P=0.004), and maximum tumor diameters (F=13.197, P < 0.001) among the normal, improved, and unimproved postoperative visual field groups. Multivariate logistic regression analysis indicated that preoperative best corrected visual acuity (BCVA) (β=2.241, P=0.011, OR=9.406), preoperative MD absolute value (β=0.195, P < 0.001, OR=1.215), preoperative full superotemporal quadrant visual field defect (β=1.614, P=0.002, OR=5.024), and the maximum tumor diameter (β=0.512, P=0.023, OR=1.668) were the relatively independent prognostic factors for postoperative visual field improvement. Conclusions: After endonasal transsphenoidal pituitary tumor resection surgery, the visual field improvement was greatest at 1 week. Preoperative BCVA, preoperative MD absolute value, preoperative full superotemporal quadrant visual field defect, and the maximum tumor diameter were the relatively independent prognostic factors for postoperative visual field improvement.