Central retinal vessel trunk exit and location of glaucomatous parapapillary atrophy in glaucoma

Objective: To evaluate whether the position of the central retinal vessel t runk exit on the lamina cribrosa spatially correlates with the location of parapapillary atrophy in glaucoma. Design: Clinic-based, observational, cross-sectional study. Patients: Color stereo optic disc photographs of 95 patients with primary o r secondary open-angle glaucoma and 65 healthy persons were morphometricall y evaluated. The intrapapillary and parapapillary region was divided into f our quadrants. We determined the position of the central retinal vessel tru nk exit on the lamina cribrosa surface and measured the area of parapapilla ry atrophy and neuroretinal rim in the four quadrants, Main Outcome Measures: The area of neuroretinal rim and parapapillary atrop hy and the position of the central retinal vessel trunk exit. Results: Comparing measurements between opposite disc quadrants showed that beta zone of parapapillary atrophy was significantly (P < 0.05) larger and that the neuroretinal rim was significantly smaller when beta zone and neu roretinal rim were measured in the disc quadrant most distant to the centra l retinal vessel trunk exit, than if the beta zone and neuroretinal rim wer e measured in the quadrant containing the vessel trunk exit. Comparing meas urements in the disc quadrants between eyes with different positions of the central retinal vessel trunk exit revealed that, in the respective disc qu adrant, the beta zone was significantly larger and the neuroretinal rim was smaller in eyes with the vessel trunk exiting in the opposite disc quadran t than in eyes with the vessel trunk exit located in the respective disc qu adrant where the measurements were obtained. Conclusions: Position of the central retinal vessel trunk exit on the lamin a cribrosa influences the location of parapapillary atrophy in glaucoma. Th e longer the distance to the central retinal vessel trunk exit, the more en larged is parapapillary atrophy and the smaller is the neuroretinal rim. Th is relationship agrees with the spatial relationship between glaucomatous n euroretinal rim loss and enlarged parapapillary atrophy in glaucoma. Diagno stically, it may indicate that, in eyes with an abnormal configuration of p arapapillary atrophy or with an abnormal position of the central retinal ve ssel trunk exit, early glaucomatous rim changes should be looked for in the disc sector that is most distant to the central retinal vessel trunk exit and where parapapillary atrophy may be relatively large. Ophthalmology 2001 ;108:1059-1064 (C) 2001 by the American Academy of Ophthalmology.