Characteristics of multifocal eletrotetinogram in nonarteritic anterior ischemic optic neuropathy and its relationship with visual acuity and macular central retinal thickness

Abstract

Objective To observe the characteristics of multifocal eletrotetinogram (mfERG) in nonarteritic anterior ischemic optic neuropathy (NAION) and its relationship with visual acuity and macular central retinal thickness (CRT). Methods By means of patients self-contrast analysis. 40 patients (40 eyes) with NAION were collected underwent the examinations of best corrected visual acuity, fundus color photography, fundus fluorescein angiography and field of vision. All the disease and normal eyes had underwent the examination of frequency-domain optical coherence tomography (fdOCT) and mfERG. The CRT and retinal thickness about perifovea, parafovea were documented with fdOCT. All patients underwent the retinal macular function exam with mfERG. Centered by macular fovea, the reaction zone were divided into 5 rings from inside to outside by circles, ring 1 0.00°, ring 2 5.44°, ring 3 10.31°, ring 4 16.31°, ring 5 23.42°. Treated ring 1 hexagon as macular center, the amplitude densities of P1 wave, the amplitude of P1 and N1 wave, and the latencies of P1and N1 wave at every ring were observed. The relationship between mfERG characteristics and visual acuity or CRT were analyzed by Spearman correlation analysis. Results fdOCT revealed that there was significantly statistical difference in the retinal thickness about perifovea between disease eyes and contralateral eyes (P 0.05). mfERG revealed that the decrease of amplitude densities about P1 wave at ring 1 to 2 had significantly statistical difference between two groups (P 0.05). The correlation analysis revealed that the amplitude densities and amplitude of P1 wave at ring 1, amplitude of N1 wave at ring 1 had no effect on visual acuity (r=-0.087, 0.195, -0.134; P>0.05) and CRT(r=-0.154, 0.365, 0.412; P>0.05). Conclusions Compared with contralateral eyes, the disease eyes were significantly decrease in amplitude densities of P1 wave at ring 1 to 2, amplitude of P1 and N1 wave at ring 1.There are no correlated between the amplitude densities of P1 wave at ring 1, amplitude of P1 and N1 wave at ring 1 and visual acuity or CRT. Key words: Optic neuropathy, ischemic/diagnosis; Electroretinography