Abstract
Background: Endoscopic transsphenoidal excision has revolutionized the surgical management of pituitary macroadenoma. There have been several retrospective studies on the factors determining the visual outcome after surgical excision of pituitary adenoma, but very few prospective studies were published in this context. This is a prospective study of the factors predicting visual outcome following endoscopic transsphenoidal excision of pituitary adenoma. Various factors like age, duration of visual symptoms, the volume of the tumour, suprasellar extension, parasellar extension, type of adenoma, pituitary apoplexy, completion of excision, fundoscopic changes, and preoperative visual deficits were studied.
Methods: Single-centre prospective observational study done between November 2016 to December 2018. Thirty patients with pituitary macroadenoma who underwent trans nasal endoscopic excision were studied with preoperative and postoperative visual impairment scores (VIS). The visual outcome was categorized as a good outcome if there was more than a 5% improvement in VIS and worse otherwise. Various predictors that may influence the outcome were statistically compared.
Results: 83.3% of patients (n=25) showed improvement in their vision at 6months follow-ups. Overall visual outcome (considering both parameters, visual acuity and visual field together) was dependent on suprasellar extension (P=0.01), completion of excision (P=0.004), and primary optic atrophy (P=0.018). On subgroup analysis, recovery in visual acuity was significantly determined by the preoperative tumour volume(P=0.041), suprasellar extension (P=0.006), completion of excision(P=0.003), and primary optic atrophy (P=0.013). The improvement in the field of vision depended on the severity of preoperative field defects (P=0.04) and completion of excision (P=0.01).
Conclusions: The factors predicting the early visual outcome were the suprasellar extension, completion of excision, preoperative field deficits, and primary optic atrophy. This study highlights the importance of early and proper intervention in pituitary adenomas managed surgically to procure the desired result.

Key words: Pituitary neoplasms, Suprasellar extension, Transsphenoidal approach, Visual outcome, Endoscopic surgery