The Role of Optical Coherence Tomography in the Early Detection of Chiasmal Compression: Hypophyseal Adenoma Presenting With Bitemporal Nerve Fiber Layer Thinning.

Hypophyseal adenomas can present with or without minimal visual disturbances. We present a case of a 40-year-old male with a hypophyseal adenoma, highlighting bitemporal peripapillary retinal nerve fiber layer (NFL) thinning on optical coherence tomography (OCT) as a major sign of chiasmal damage despite minimal asymmetrical nonspecific changes detected on initial visual field testing. The bitemporal NFL thinning prompted further evaluation with MRI, which confirmed the presence of a macroadenoma of the hypophysis. Despite the large adenoma, treatment with cabergoline led to regression, and the patient's visual field improved. This case underscores the importance of OCT in detecting subtle structural changes associated with pituitary tumors, as it can facilitate early diagnosis and prompt intervention for optimal visual outcomes.