Preoperative Peripapillary Retinal Nerve Fiber Layer Thickness as the Prognostic Factor of Postoperative Visual Functions After Endoscopic Transsphenoidal Surgery for Pituitary Adenoma

PURPOSE: To evaluate the prognostic ability of preoperative peripapillary retinal nerve fiber layer thickness (pRNFLT) for predicting postoperative visual functions, including the visual field index (VFI) and visual acuity (VA), of subjects with pituitary adenoma (PA) who were treated with endoscopic transsphenoidal surgery for pituitary adenoma (ETSS-PA) exclusively. SUBJECTS AND METHODS: This 11-year retrospective study was performed at a single institution in Thailand. Sixty-six eyes of 33 subjects who had a PA compressing the anterior visual pathway and were treated with ETSS-PA alone were included. The pRNFLT was measured globally and in the four quadrants preoperatively, using optical coherence tomography. Multivariable analysis and area under the curve (AUC) were used to demonstrate the prognostic ability of preoperative pRNFLT for postoperative visual functions (> 1 month but < 6 months after ETSS-PA). RESULTS: The mean postoperative VFI and median postoperative VA were 79.45% ± 24.24% and 0.14 [interquartile range: 0.02, 0.40] logarithm of the minimum angle of resolution. Among the 56 eyes with a reliable postoperative VFI, thicker preoperative temporal (odds ratio, 1.18; p = 0.024) and inferior (odds ratio, 1.07; p = 0.013) pRNFLT values were associated with a postoperative VFI > 90%. The strongest association occurred with the preoperative temporal pRNFLT (AUC = 0.821, 95% CI: 0.720–0.923) with a cut-off value of 60 µm. Multivariable analysis for all 66 eyes showed that thicker preoperative inferior-quadrant pRNFLT (odds ratio, 1.05; p = 0.001) was associated with a postoperative VA of at least 20/25. The strongest performance was found with the preoperative inferior pRNFLT (AUC = 0.732, 95% CI: 0.615–0.849) with a cut-off value of 105 µm. CONCLUSION: Preoperative pRNFLT offers clinical utility for predicting visual functions after ETSS-PA. Temporal pRNFLT ≥ 60 µm and inferior pRNFLT ≥105 µm predicted postoperative VFI > 90% and postoperative VA better than or equal to 20/25, respectively.