Supplementary Material for: Optical coherence tomography abnormalities as the presenting sign of an involuted sellar/suprasellar mass

Introduction: Pituitary adenomas are benign tumors that can lead to visual loss through compression of the optic chiasm. Patients with pituitary adenomas often present with visual field defects (commonly bitemporal hemianopia), but some may be asymptomatic. In such cases, abnormalities may only be detected through visual field testing or optical coherence tomography (OCT) of the ganglion cell-inner plexiform layer (GCIPL), may provide a more sensitive method for detecting such abnormalities. Case presentation: A 72-year-old man was incidentally found to have binasal OCT-GCIPL thinning during a routine eye examination. Visual acuity was 20/20 in both eyes. Pupils were equal and reactive without a relative afferent pupillary defect. His Humphrey 24-2 SITA-Fast visual field test results were normal. An MRI revealed a non-enhancing (cystic) sellar/suprasellar mass measuring 1.7 cm craniocaudal by 2.1 cm anteroposteriorly, without associated optic chiasm compression. The lesion was suspected to be either a cystic pituitary adenoma or a Rathke’s cleft cyst. Follow-up examination one year later showed all findings remained stable, including an unchanged visual acuity, visual fields, OCT-GCIPL and MRI. Conclusion: The binasal thinning observed on OCT-GCIPL in this case, despite the absence of chiasmal compression on MRI, is suggestive of previous compression of the optic chiasm. This case highlights the potential for spontaneous regression of pituitary adenomas and underscores the importance of OCT-GCIPL as a vital tool for detecting optic chiasmal damage.