Abstract
Purpose: :
To determine the correlation between retinal nerve fiber layer thickness and visual field threshold in asymmetric glaucoma using regional analysis of superior and inferior arcuate areas.
Methods: :
14 patients with asymmetric glaucoma ( POAG, N=5; NTG, N=6; Pigmentary Glauc, N=2, Pseudoexfoliation, N=1) were chosen in which the better eye had a normal (p>5% level) mean deviation (HVF SITA standard 24–2). Correlations of the arcuate retinal nerve fiber layer (RNFL) thickness determined by optical coherence tomography (OCT) were made with the threshold light sensitivity (decibles) of the corresponding visual field. The correlations were made using the most damaged eye vs. the inter–ocular differences in measurements.
Results: :
A highly significant correlation was found between the arcuate bundle regions of the OCT and the corresponding area of visual field (Garway–Heath method) in the eye with the abnormal visual field mean deviation (linear correlation coefficient R=0.64, p=0.001; non–linear correlation R=0.72, p=0.002). The non–regional correlation between average visual field threshold for the whole visual field and the average RNFL thickness was not significant. Correlation of inter–eye differences in arcuate RNFL and corresponding threshold were not as significant as monocular correlations.
Conclusions: :
Regional analysis of structural–functional relationships in asymmetric glaucoma is highly significant and may reflect a mechanism of damage in this subgroup of glaucoma patients that is unique.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • visual fields • nerve fiber layer