PURPOSE: To determine normative values for focal electroretinography in normal young adults, according to the standard protocol recommended by the International Society for Clinical Electrophysiology of Vision - IsCEV. METHODS: 33 normal volunteers aged from 14 to 38 years (mean 22.96±5.73) were included in this study. Focal electroretinography was recorded by corneal electrode after white flicker light stimulation in the macula at high temporal frequencies -42Hz and 31.25Hz. Focal electroretinography parameters as amplitude (nanovolts) and latency (milliseconds) were extracted and analyzed after discrete Fourier transformation. Median, values below 95% and above 95%; maximum; minimum and percentiles were calculated for both parameters; a t test was calculated between amplitudes and latencies for both frequencies. RESULTS: For 42Hz. Amplitude: median 614nV; below 95% 529nV; above 95% 650nV; minimum 370 nV; maximum 794 nV; 2.5th percentile 378.8nV; 97.5th percentile 779.6nV. Latency: median 26.4ms; below 95% 25.4ms; above 95% 26.8ms; minimum 23.4ms; maximum 28.2ms; 2.5th percentile 23.8ms; 97.5th percentile 27.88ms. For 31.25Hz. Amplitude: median 632nV; below 95% 429nV; above 95% 750nV; minimum 364nV; maximum 1036nV; 2.5th percentile 364.8nV; 97.5th percentile 1018.4nV. Latency: median 30.1ms; below 95% 29.3ms; above 95% 31.2ms; minimum 25.9ms; maximum 33.9ms; 2.5th percentile 27.18ms; 97.5th percentile 33.34ms. CONCLUSIONS: Normal limits for focal electroretinography according to the International Society for Clinical Electrophysiology of Vision, guidelines were established in a cohort of young adults. Comparable amplitude values were found for both 42 Hz and 31.25 Hz temporal frequencies. However, latencies was significantly faster for 42 Hz stimuli.
Electroretinography; Electroretinography; Retina; Macula lutea; Reference values
