Position of the central retinal vessel trunk and location of visual field and parapapillary nerve fibers damage in early to moderate glaucoma

Abstract

AbstractPurpose To address the question of whether the position of the central retinal vessel trunk (CRVT) exit in the optic disc has a spatial relationship with glaucomatous damageMethods This clinical observational study included patients with early to moderate primary open‐angle glaucoma. The position of the CRVT exit on the lamina cribrosa was evaluated on optic disc photographs. Visual field tests and retinal nerve fibers layer (RNFL) thicknesses, as measured by optical coherence tomography, were evaluated.Results The study included 65 eyes with a CRVT mostly decentered into the nasal region followed by the temporal half of the optic disc. Comparing measurements between the opposite disc quadrants indicated that the RNFL thickness was significantly thinner in the inferotemporal quadrant when the CRVT was located in the superonasal quadrant compared with an exit in the inferonasal (p=0.0183) or temporal (p=0.0039) quadrant. The distance from the CRVT to the nasal disc border was significantly smaller and correlated positively with the occurrence of RNFL abnormality in the temporal region (p=0.0334). Visual field defect incidence was higher in the superonasal quadrant of the pattern deviation plot when the CRVT was located in the superonasal quadrant compared with an exit in the inferonasal quadrant (p<0.0003). Temporal visual field abnormalities occurred more often when the CRVT exit was located in the temporal part of the optic disc than when the CRVT exit was located in the nasal half (p=0.008).Conclusion Local susceptibility for development of glaucomatous damage correlates with the distance to the CRVT, which may act as a stabilizing element against the deformation of the lamina cribrosa.