Smell perception in normal tension glaucoma patients

PURPOSE The aim of this study was to quantify the ability to identify odors in normal tension glaucoma (NTG) patients and healthy subjects with and without a primary vascular dysregulation (PVD). METHODS Both self-assessment of smell perception and evaluation of odor identification by means of the 12-item odor identification test ("Sniffin' Sticks") were performed in the following groups of subjects: 1) 18 NTG patients with PVD (G+), 2) 18 NTG patients without PVD (G-), 3) 18 healthy subjects with PVD (H(+)) and 4) 18 healthy subjects without PVD (H-). The subjects self-assessment of smell perception was evaluated before the Sniffin' Sticks test by asking them to judge their ability to identify odors as either "average," "better than average," or "worse than average." RESULTS Subjects with a PVD (G+ and H(+)) can identify odors significantly better than those without a PVD (G- and H-; in a score scale of 1-12 the score point difference=2.64, 95% CI=1.88-3.40, p<0.001). No significant differences in odor identification was found between NTG (groups G+ and G-) and healthy subjects (groups H(+) and H-; score point difference=-0.14, 95% CI=-0.9-0.62, p=0.72). CONCLUSIONS Subjects with a PVD can identify odors significantly better than those without a PVD.