Local and multifocal ERG in age‐related macular degeneratıon.

Abstract

Abstract Purpose: To assess the macular ERG responses in different forms of AMD with OCT‐visualisation. Methods: 60 patients (120 eyes) wıth AMD, aged 57‐82, were examined. The groups were formed based on clinical examination, OCT and fluorescein angiography data. Local ERG (L‐ERG) to a red and green stımulus was recorded wıth MBN ERG system (Russıa). Multıfocal ERG was recorded wıth RETIscan system (Roland Consult, Germany). Results: In group 1 wıth hard drusen (18 eyes) ERG responses were in normal range. In group 2 with soft confluent drusen (18 eyes) a‐wave implicit tıme (IT) was prolonged (p=0,007);N1 of mfERG in normal range. b‐wave amplitude of L‐ERG to red stimulus was reduced (p=0,014), P1 of mf‐ERG reduced in fovea and parafovea (р<0,001). In a group 3а (31 eyes) wıth focal RPE atrophy,a‐wave IT of M‐ERG prolonged (p=0,002), P1 reduced in fovea (p=0,04). In a group 3b (16 eyes) with focal RPE atrophy and hyperpigmentation (VA 0,4‐0,1) a‐ and b‐wave reduced (p<0,001),P1 reduced in fovea and parafovea (р<0,05), N1 in foveal hexagone (p=0,04). In a group 4a with CNV with CMO foveal and parafoveal b‐wave amplitude reduced (p<0,05), P1 and N1 reduced (р<0,001). P1 in paramacular ring was reduced (р<0,05). In group 4b with RPE‐detachment a‐wave prolonged, a‐and b‐wave reduced, P1 and N1 reduced (р<0,001). Conclusions: The most sensitive indicators of macular dysfunction in AMD are the implicit time of a‐wave to a red stimulus local ERG and P1 response density of mf ERG in foveal hexagone. Normal amplitude and implicit time of N1 in soft drusen and early RPE‐atrophy in eyes with prolonged a‐wave of local ERG provides the evidence of smaller contibution of cones to N1 of FOK of mf ERG.