Spontaneous improvement of rod system function in a patient with melanoma-associated retinopathy

To report spontaneous improvement of rod visual function in a patient with melanoma-associated retinopathy (MAR).

Electroretinography (ERG), and dark-adapted psychophysical thresholds were performed on a male patient with the MAR syndrome, during four visits over a period of almost 7 years.

There was a spontaneous, subjective improvement in night vision and a decrease in the severity of photopsias of the patient's left eye between the initial and most recent visits. Both the dark-adapted rod-isolated and maximal-flash b-wave ERG amplitude also improved his initial visit to the most recent visit. By comparison, the light-adapted brief-flash and flicker ERG amplitudes were initially within the range of normal in the left eye but showed a subsequent reduction in amplitude. The ERG response of the right eye was only measured at the most recent visit, but gave a dark-adapted response that was similar to that of the left eye on the initial visit, and a light-adapted response that was similar to that of the left eye on the most recent visit. Rod sensitivity was substantially better in the left eye than in the right eye by psychophysical testing, although the right eye did show a noticeable level of improvement in rod thresholds between the initial and most recent visits.

These findings document the potential for spontaneous improvement in electrophysiological and psychophysical rod function, as well as in subjective symptoms, in patients with the MAR syndrome.