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Retinitis pigmentosa (ERG)

The EGR is usually affected profoundly and early in the retinitis pigmentosa disease process, with both scotopic (rod) and photopic (cone) function being affected. Here, a normal ERG is contrasted to a retinitis pigmentosa patient ERG. The top 3 records are from a normal patient and represent from the top down: (1) scotopic and photopic function; (2) isolated photopic function; and (3) isolated scotopic function. The bottom record is from a retinitis pigmentosa patient and reflects an absence of scotopic function. (Contributed by Dr. James Walters.)