Unilateral cone dysfunction with bull's eye maculopathy

Objective: To report a Japanese subject who presented with an acute-onset, unilateral cone dysfunction with bull's eye maculopathy and to describe the functional changes determined by psychophysical and electrophysiologic tests. Design: A single observational case report. Methods: In addition to a complete ophthalmic examination, the subject underwent some electrophysiologic and psychophysical tests. Main Outcome Measures: Kinetic visual field test, cone and rod perimetry (two-color perimetry), full-field electroretinograms (ERGs), focal macular ERGs, and multifocal ERGs. Results: The full-field ERGs and two-color perimetry showed a predominant loss of cone function in the right eye, whereas the left eye was normal. Cone perimetry and multifocal ERGs revealed that there were small regions functioning normally and other retinal areas that were severely altered in the right eye. Conclusions: The topographical function analysis suggested that the disorder affected the retina unevenly. The cause of this rare case of unilateral cone dysfunction with bull's eye maculopathy still remains unknown.