Altitudinal visual field asymmetry is coupled with altered retinal circulation in patients with normal pressure glaucoma

Aim-To compare the effect of altitudinal asymmetric glaucomatous damage on retinal microcirculation in patients with normal pressure glaucoma (NPG). Methods-In a prospective cross sectional study patients with NPG (washed ou t for antiglaucomatous therapy) and altitudinal asymmetric perimetric findi ngs between the superior and inferior hemisphere (Humphrey 24-2) (n=18) wer e included and compared with 20 NPG patients with symmetrical field defects and 18 healthy subjects. Fluorescein angiograms were performed using a sca nning laser ophthalmoscope. Using digital image analysis, arteriovenous pas sage time (AVP) and vessel diameters were assessed for comparison of corres ponding affected and less affected temporal arcades. Results-Both affected and less affected hemispheres showed significantly pr olonged AVP times (p<0.001) when compared with healthy subject data. In hem ispheres with more severe glaucomatous field loss the AVP times were signif icantly (p=0.04) prolonged compared with the less affected hemisphere (AVP affected 3.1 (SD 7) seconds v AVP less affected 2.61 (1.4) seconds). There was no asymmetry effect on arterial and venous diameter measurements. Conclusion-Altitudinal visual field defects are Linked together with circul atory deficits of the retinal tissue. The attenuated circulation seems to b e a considerable factor in the natural course of glaucomatous optic neuropa thy.