Optical coherence tomography detects early optic nerve damage before visual field defect in patients with pituitary tumors

Abstract

Abstract Purpose Optical coherence tomography (OCT) is a useful tool for predicting visual recovery after the removal of pituitary tumors. However, the utility of OCT in patients with pituitary tumors and a normal visual field is unclear. We aimed to analyze OCT features in pituitary tumors without visual field defects. Methods Pituitary tumors without visual field defects were selected. A total of 138 eyes from 69 patients, assessed by the Humphrey visual field test and OCT, were enrolled in this study. Using preoperative coronal sections of MR images, patients were divided into chiasmal compression (CC) and non-chiasmal compression (non-CC) groups, and OCT characteristics were examined. Results The CC and non-CC groups consisted of 40 and 29 patients, respectively. There were no differences in age, sex, tumor type, or degree of visual field testing, but the tumor size was different between the two groups. On OCT, macular thickness ganglion cell complex (mGCC) was significantly thinner in the CC group than that in the non-CC group (112.5 vs 117.4 um, P < 0.05). Based on a database of healthy participants, 24% and 2% of eyes in the CC and non-CC groups had abnormal mGCC thickness (P < 0.01), respectively. In a sub-analysis of the CC group, patients with an abnormal mGCC thickness were older than a normal one (58.2 vs 41.1 years, p < 0.01). Conclusions OCT can detect early optic nerve damage due to optic CC by pituitary tumors, even in normal visual fields. The degree of mGCC thinning may provide an appropriate surgical timing for pituitary tumors that compress the optic chiasm.