CORRELATION OF TUMOR SIZE WITH VISUAL STATUS AMONGST PATIENTS WITH PITUITARY ADENOMA

Abstract

Background: Pituitary adenomas are benign neoplasms that can lead to substantial visual impairment due to their anatomical proximity to the optic chiasm. Visual dysfunction is often proportional to tumour size, with bitemporal hemianopia being the hallmark of chiasmal compression. Objective: To evaluate the correlation between tumour size and pre-operative visual field status in patients with pituitary adenoma. Study Design: Observational cross-sectional study. Settings: Conducted at the Punjab Institute of Neurosciences, Lahore, Pakistan. Duration of Study: 26 March 2025, 26 June 2025. Methods: A total of 60 patients aged 20–70 years with MRI-confirmed pituitary macroadenomas were enrolled. Tumor size (height) was measured in sagittal and coronal MRI scans (in mm ) using the method of Ikeda and Yoshimoto. Pre-operative visual function was evaluated using automated perimetry, with higher scores denoting greater visual impairment. Pearson correlation analysis was applied to determine the relationship between tumour size and visual field loss. Results:  The mean tumour size in the coronal plane was 1.88 cm (SD = 0.686). A strong, statistically significant correlation was observed between sagittal and coronal measurements (r = 0.696, p < 0.001), confirming inter-plane consistency. The mean perimetry score was 2.00 (SD = 1.279). Bitemporal hemianopia was the most frequent visual defect (55.9%), followed by unilateral temporal with contralateral nasal hemianopia (17.6% and 14.7%, respectively), complete blindness (8.8%), and normal fields (2.9%). A significant positive correlation was found between larger coronal tumour size and worsening visual field scores (r = 0.682, p < 0.001; 95% CI: 0.482–0.821). Conclusion: Larger pituitary macroadenomas are strongly associated with greater visual field impairment pre-operatively. The predominance of bitemporal hemianopia supports classic optic chiasm compression, while the occurrence of atypical defects highlights anatomical variability. These findings reinforce the necessity for early neuroimaging and comprehensive visual assessment to facilitate prompt surgical intervention and preserve visual function.