Optical Coherence Tomography in Pituitary Adenomas Serves as a Predictor for Visual Functionality Postresection
Introduction: The current gold standard for evaluating functional impairment of pituitary tumors is Humphrey visual field (HVF) testing. However, optical coherence tomography (OCT) may serve as an alternative in predicting return of visual function in postoperative surgically resected patients diagnosed with a pituitary adenoma.
Methods: After application of exclusion criteria, we identified 12 patients with pituitary adenomas that had been treated surgically at our institution from 2017 to 2019. Patient pre- and postoperative visual acuity, mean deviation, HVF features, retinal nerve fiber layer (RNFL) characteristics, retinal ganglion cell layer (RGCL) thickness, and duration of symptoms were retrospectively reviewed.
Results: The mean age at OCT examination was 48.4 years (range: 10–79 years old), and nine patients were male (75.0%). The most common presenting symptoms were endocrine dysfunction (n = 7, 58.3%) and bitemporal hemianopsia (n = 7, 58.3%), followed by blurred vision in one or both eyes (n = 6, 50.0%). Three patients (25.0%) reported blurred vision for over 6-month prior to surgical intervention. Patients were grouped into three cohorts for analysis based on the degree of postoperative visual recovery on HVF and OCT testing: complete recovery (group 1), fair but incomplete recovery (group 2), and minimal or no recovery (group 3). Preoperatively, group 1 had RNFL and RGCL thickness within normal limits, with mean values of 99.3 µcm (±3.9) and 79.1 µcm (±3.0), respectively. Group 2 had mild-to-moderate RNFL and RGCL loss preoperatively, with mean values of 81.1 µcm (±1.8) and 66.1 µcm (±4.9), respectively. Group 3 had severe, diffuse RNFL, and RGCL loss preoperatively, with mean values of 65.7 µcm (±3.2) and 52.0 µcm (±1.0), respectively. Mean preoperative RNFL thickness and RGCL thickness were both significantly different between the three groups (p = 0.00004 and 0.007). Single-factor ANOVA was utilized to determine the statistical significance of the difference in preoperative RNFL and RGCL thickness between groups.
Conclusion: In our series, we report that OCT testing is more important than visual field testing in the evaluation for visual prognosis in chiasmal compression. Patients with normal OCT RNFL and RGCL thickness preoperatively had the best prognoses and complete visual functional recovery postoperatively. Patients with mild-to-moderate RNFL thinning and RGCL loss preoperatively had relatively good prognoses but had residual visual defects postoperatively. Patients with severe RNFL thinning and RGCL loss preoperatively had the worst prognoses with minimal or no visual functional recovery postoperatively. Therefore, predictive value of OCT in restoration of visual function postoperatively may be used in guiding clinical decision making toward the management of pituitary adenomas.
No conflict of interest has been declared by the author(s).
12 February 2021 (online)
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