Distal Nasal Part of the Visual Field and RNFL in Primary Open-Angle Glaucoma.

Abstract

The aim of this study was to compare changes in the conventionally undiagnosed distal nasal visual field with RNFL in patients with early primary open-angle glaucoma (POAG). 59 eyes of 32 patients (18 women, 14 men) with early stage POAG were included. All eyes were found to have a normal visual field (fast threshold program of 50 degrees nasally and 22 degrees temporally) with the Medmont M700. Visual acuity was 1.0 (with a possible correction ±3 D), and they had no other ocular pathology except glaucoma. The visual field was subsequently examined with the same instrument by moving the fixation point 40 degrees temporally (spatially adaptive program) and simultaneously turning the head 10 degrees nasally. A total of 89 examination points were included using flicker stimuli in a range of 0-120 degrees nasally. Nerve fiber layer (RNFL) and vessel density (VD) was measured using the in-built software of the Avanti RTVue XR instrument. Using Pearson's correlation coefficient, the results of visual field examination with RNFL without and after correction (by subtracting VD from total RNFL value) in the superior-nasal (SN-5) and inferior-nasal (IN-8) segments were compared. In all eyes, changes were found in the distal periphery of the nasal part of the visual field. No correlation was noted by comparison with RNFL. After adjusting RNFL for VD, we observed no correlation in the SN segment (5) (r=-0.03) and a very weak correlation in the IN segment (8) (r=-0.16). With a normal visual field tested by the rapid threshold glaucoma program, changes in the distal part of the nasal periphery of the visual field were found in the entire cohort and did not correlate with the RNFL and RNFL results after correction from VD.