[Visual field index and pituitary tumors resected by microsurgical transsphenoidal approach].

Background: Pituitary adenomas are the third most common intracranial tumor. Due to their growth, they may cause endocrine disturbances, compression, and visual deficits, particularly visual field defects. The Visual Field Index (VFI) is an objective parameter that accurately quantifies visual improvement or deterioration. Transsphenoidal resection is the first-line treatment; therefore, pre- and postoperative visual assessment is essential for follow-up and prognosis. Objective: To correlate pre- and postoperative VFI in patients with pituitary adenomas who underwent microscopic transsphenoidal surgery at the Centro Médico Nacional de Occidente. Materials and methods: A retrospective study of patients operated on between January 2020 and January 2024 was conducted, including those with pre- and postoperative automated perimetry. Both sexes and all ages were included, provided they had complete medical records, magnetic resonance imaging, and visual field testing. VFI values were compared using descriptive and correlational analyses. Results: Thirty-two patients were analyzed (mean age 54 years); 29 had comorbidities, with hypothyroidism being the most common (56%). The most frequent visual deficit was bitemporal hemianopia (60%). In the right eye, the mean VFI increased from 50.1% to 56.1% (p = 0.002); the median increased from 55% to 68.5% (p = 0.001). In the left eye, the mean changed from 54.6% to 56.7% (p = 0.472); the median from 55.5% to 64.5% (p = 0.537). A greater proportion of improvement was observed in the right eye. In diabetic patients, a reduction in left-eye VFI was noted. Conclusions: Postoperative VFI showed an overall increase following microscopic transsphenoidal resection, supporting its usefulness as a practical and objective parameter for evaluating visual function.