Abstract
Abstract: :
Purpose: to examine the wall thickness of retinal vessels. Methods: The cohort used for this study consisted in 515 patients (age between 7 and 86 years). Among them were 91 patients with normal tension glaucoma (NTG; age, 59.0±11.6 years, mean visual field defect 5.9±5.7 dB) and 241 subjects without any eye disease (age, 49.2±13.7 years; mean visual field defect 1.8±2.1 dB). The vessel wall thickness was measured in the retinal temporal superior artery and vein by scanning laser Doppler flowmetry (HRF, Heidelberg Engineering, Germany). Results: The vessel wall thickness was significantly correlated with the vessel diameter in both, arteries (r=0.61, p<0.001) and veins (r=0.42, p<0.001). The critical limit of the normalized vessel wall thickness (80th percentile) was 0.08 (artery) and 0.18 (vein). In NTG patients both, mean arterial vessel diameter (104.1±13.6 υm) and mean venous vessel diameter (127.8±18.5 υm) were significantly reduced (control, 109.8±15.7 υm) [artery]; 134.6±21.2 υm) [vein], p<0.002 each). In NTG patients normalized venous vessel wall thickness was significantly increased (0.146±0.044 vs. control, 0.131±0.044 [non–dimensional], p<0.001), but normalized arterial vessel wall thickness was unchanged. In older subjects without any eye and internal disease (age, 60.1±6.9 years) vessel wall thickness was increased in both, artery (p=0.04) and vein (p=0.005) as compared to younger healthy individuals (age, 35.1±9.3 years, p<0.001), but the arterial and venous vessel diameter was not different.Conclusions:In patients with NTG vessel diameter in retinal arteries and veins was reduced, whereas the vessel wall thickness in veins was increased. The observed effect might be also provoked by increased age in this group.
Keywords: retina • blood supply • imaging/image analysis: clinical