O-EV003. Role of multifocal electroretinogram in assessment of early retinal dysfunction in hypertensive patients

Abstract

Introduction . Hypertensive retinopathy is the second most common cause of retinopathy following diabetes, probably caused by retinal ischemia as a consequence of atherosclerotic irreversible changes of systemic hypertension. Non-uniform functional retinal abnormalities are difficult to detect by full-field ERG and needs the disease to reach advanced changes to be affected. mfERG offers an objective noninvasive and reliable method to measure retinal function. It allows simultaneous recording of local ERG responses from different parts of the retina. Also previous studies suggested that the abnormalities in retinal electrophysiological studies usually precede fundus signs of retinopathy as mfERG is affected early by the neurodegenerative process. our aim in this study was to investigate localized retinal dysfunction in hypertensive patients using multifocal electroretinogram (mfERG) and to assess its sensitivity as an early predictor for the development of retinopathy in hypertensive patients. Methods . Ninety-eight eyes were included in this case-control study. Twenty-eight eyes of healthy subjects served as a control group (group I). Seventy eyes belonged to patients with systemic hypertension assigned into two groups; group II including 39 eyes of hypertensive patients with normal fundus and group III including 31 eyes of patients with signs of hypertensive retinopathy. All participants were subjected to complete ophthalmic and electrophysiological examination using mfERG. N1 and P1 wave amplitudes and implicit times from the central hexagon and four concentric rings across the visual field were analyzed. Results . mfERG amplitudes were significantly reduced in hypertensive group with retinopathy than in controls. N1 amplitude was significantly reduced in the most eccentric ring in eyes of hypertensive patients with normal fundus. Conclusion . mfERG is a sensitive objective tool for assessment of retinal dysfunction in hypertensive patients. mfERG amplitude is a promising predictor for early development of retinopathy in systemic hypertension.