Accommodative response changes with age measured by pattern electroretinogram.

Abstract

To evaluate whether the transient pattern electroretinogram reflects accommodation, we studied the amplitudes of the P-N component of transient pattern electroretinograms that were elicited in normal volunteers by reversing the checkerboard pattern. The stimuli were presented at a rate of three-reversals per second at a viewing distance of 20 cm. Each subject wore a lens that corrected for distance vision. The ophthalmic lenses were placed in front of the eye. A +12-diopter lens was used first, followed by lenses in decreasing 1-diopter steps, including minus lenses, until no response was recordable. The P-N amplitude was then plotted against increased accommodative stimulus. The graph showed a rapid increase to around 4 diopters, and then a slow decrease with increasing minus lens power. The gradually decreasing part of the graph became steeper under cycloplegic conditions. The amplitude of accommodative response was defined as the difference in diopters between the lens powers for eliciting an electroretinogram amplitude after cycloplegia was achieved and in the untreated pupil. The amplitude of accommodative response attenuated significantly in those subjects older than 40 years.