Quantitative Assessment of Visual Field Recovery Following Transspheniodal Pituitary Adenoma Excision and its Time Course

Abstract

Background: Pituitary adenomas are a significant subset of intracranial tumors, constituting approximately 10-15% of all primary brain tumors. These benign tumors often lead to various clinical symptoms, including hormonal imbalances and visual field defects due to optic chiasm compression. The transsphenoidal approach for pituitary adenoma excision is favored for its minimal invasiveness and favorable outcomes. However, the timeline and extent of visual field recovery post-surgery remain areas of active research.

Objective: This study aimed to quantitatively assess and track visual field recovery in patients following transsphenoidal pituitary adenoma excision and to identify factors influencing the recovery process.

Methods: This descriptive observational study was conducted at the Department of Neurosurgery, Pakistan Institute of Medical Sciences (PIMS), Islamabad, from June 16, 2023, to March 31, 2024. Forty-six consecutive patients, aged 18-70 years, who underwent transsphenoidal pituitary adenoma excision and had documented visual field impairments, were included. Exclusion criteria were previous pituitary surgery, pre-existing visual field abnormalities not attributable to pituitary adenoma, and inability to perform visual field testing. Preoperative visual field measurements were taken within two weeks before surgery using Humphrey visual field testing. Postoperative evaluations were performed immediately after surgery (within 48 hours), and at one month, two months, and three months. Visual field indices, including mean deviation (MD) and pattern standard deviation (PSD), were recorded. Data were analyzed using SPSS version 25, with descriptive statistics for patient demographics and tumor characteristics, and inferential statistics (Student's t-test and chi-square test) for comparing visual field indices.

Results: The study included 23 male and 23 female patients, with a mean age of 52.3 years (SD ± 8.7). Tumor size averaged 2.7 cm (SD ± 0.9). Non-functioning tumors comprised 65.2% of cases. Preoperative hormonal dysfunction was present in 39.1% of patients. Preoperative visual field indices showed a mean MD of -5.2 dB (SD ± 2.1). Visual field improvement was noted postoperatively, with mean MD values of -4.0 dB (SD ± 1.8) at 48 hours, -3.5 dB (SD ± 1.7) at one month, -2.8 dB (SD ± 1.5) at two months, and -2.2 dB (SD ± 1.3) at three months. Endoscopic surgery was performed in 82.6% of cases, with a gross total resection rate of 69.6%. Postoperative complications included CSF leaks (13%) and hypopituitarism (26.1%).

Conclusion: The study demonstrated significant visual field recovery in patients following transsphenoidal pituitary adenoma excision, with notable improvements observed within the first three months post-surgery. These findings support the efficacy of the transsphenoidal approach in improving visual outcomes and highlight the importance of early intervention and comprehensive postoperative monitoring.