Acquired night blindness due to rod dysfunction after long-term hemodialysis

Purpose To report the clinical findings in 6 patients who developed night blindness after long-term hemodialysis. Study design Retrospective case series. Patients and methods The medical charts of the 6 patients were examined. The fundus photographs, spectral-domain optical coherence tomographic (SD-OCT) images, full-field ERGs, and blood chemistry panels were analyzed. Results The mean age of the 6 patients (4 men) at the time of diagnosis was 69.1 +/- 5.9 years. The mean duration of the hemodialysis was 21.8 +/- 13.4 years (7-41 years). The visual acuity of the patients was preserved at 20/30 or better except in 1 eye. Ophthalmoscopy showed white flecks that were scattered over the midperipheral retina in all the eyes. SD-OCT showed mild macular degeneration in 5 eyes. The scotopic ERGs elicited by dim flashes were absent, and those elicited by bright flashes had negative waveforms. The photopic ERGs were relatively well preserved. These data indicated a rod-specific dysfunction that may account for the night blindness. The plasma concentration of vitamin A was within the normal range in 4 of the patients and slightly lower than the normal limit in 1 of the patients. Administration of vitamin A was performed for 1 patient, and the symptom of night blindness and scotopic ERGs were improved 3 months later. Discussion Long-term hemodialysis can be associated with the night blindness that may be caused by vitamin A deficiency, even though the plasma concentration of vitamin A in these patients was within the normal range.