[Evaluation of hypertensive retinopathy through the oscillatory potentials of the electroretinogram]

Abstract

Purpose: To evaluate the behavior of the scotopic Oscillatory Potentials (OP) of total field electroretinogram (ERG) in hypertensive retinopathy.

Methods: Forty-four patients (n=44) were submitted to clinical evaluation and subdivided in to 2 groups: hypertensives (HT) and normotensives (NT). The hypertensives patients were maintained under placebo during the period of the study. Soon afterwards, they were submitted to ophthalmological evaluation and accomplishment of ERG. Total field electroretinogram (ERG), with recording of the answers: scotopic, maximum scotopic, OP scotopic, photopic and flicker.For analysis of the OP answer the latency of the first 2 peaks and the average value of the width of the first 3 peaks of the compound of 3 consecutive answers, denominated Oscillatory Index (OI) were considered.

Results: The sample was composed of 44 patients, with a mean age of 51.55 +/- 7.2 range (34 to 68) years, 24 being females. Arterial hypertension affected 26 (59.1%) of the patients, while 18 (40.9%) were normotensives. The average of the obtained IO was 257.41 microv in the NT group and of 217.81 microv in HT (p=0.006). The averages of latencies obtained for peaks 1 (NT-18.42 and HT-17.91) and 2 (NT-24.54 and HT - 24.29) were not different between the groups (p>0.05).

Conclusions: The hypertensive patients presented significantly smaller oscillatory index than the normotensives, suggesting that arterial hypertension might cause dysfunction of the internal retina.