Photopic Negative Response Reflects Severity of Ocular Circulatory Damage after Central Retinal Artery Occlusion

Abstract

Purpose: To determine the relationship of the photopic negative response (PhNR) of the photopic electroretinogram (ERG) with the degree of circulatory disturbances in eyes following central retinal artery occlusion (CRAO). Methods: The circulatory disturbance was graded as mild (group 1) when the arm-to-retina transmission time was <30 s, moderate (group 2) when the time was >30 s and severe (group 3) when concurrent choroidal circulatory damage was found. For statistical analysis, groups 1, 2 and 3 were scored as 1, 2 and 3, respectively. Photopic ERGs were elicited by either short-flash (SF) or long-flash (LF) stimuli. Results: Both the SF and LF PhNR were significantly reduced in groups 2 and 3. The PhNR amplitude was negatively correlated with the severity of the ocular circulatory disturbances (p = 0.0498, ρ = –0.507 for SF PhNR; p = 0.0050, ρ = –0.750 for LF PhNR). Conclusion: The amplitude of the PhNR became more reduced as the severity of the circulatory disturbances increased in eyes with CRAO.