Graham E Holder, Moorfields Eye Hospital, London, UK.
英国Moorfields眼科医院

The pattern electroretinogram (PERG) is the retinal response evoked by a structured stimulus, usually a reversing black and white checkerboard. It allows both objective evaluation of macular function and a direct assessment of retinal ganglion cell function. There are two main components to the normal PERG: a positive component (P50) at approximately 50ms, and a larger negative component (N95) at approximately 95ms. The exact origins of the PERG have yet to be fully ascertained, but it currently appears that N95 and ~70% of P50 arise in relation to ganglion cell function, but that some of P50 arises more distally. There is overall reduction of the PERG in macular dysfunction, with both P50 and N95 being reduced or undetectable. In contrast, ganglion cell dysfunction, either primary or consequent upon retrograde degeneration from an optic neuropathy, may selectively affect the N95 component. The PERG therefore facilitates an improved interpretation of the cortical visual evoked potential (VEP) evoked by a similar stimulus.

The combined clinical use of the PERG with ERG and/or VEP will be discussed in relation to an integrated approach to diagnosis.

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