Objective functional assessment of age-related maculopathy: a special application for the multifocal electroretinogram.

This paper gives a brief review of methods that assess objectively function in age-related maculopathy (ARM) with emphasis on a newer method, the multifocal electroretinogram (mfERG). In contrast to other electrophysiological tests, such as the full-field and focal electroretinogram (ERG) or the electro-oculogram (EOG), which measure summed responses from various cells from larger areas of the retina, the multifocal electroretinogram maps function locally with a resolution as small as four degrees within the central 30 degrees. By using different paradigms it can measure local cone- and rod-mediated functional impairment at early and late stages of ARM. This improved mapping and higher resolution of the posterior pole compared to other objective methods might lead to earlier detection of ARM. Its usefulness has been demonstrated in documenting the effects of treatment after established laser treatments, such as photodynamic therapy (PDT) and in documenting function after retinal pigment epithelial transplantation, a possible future treatment in late neovascular ARM.