Long-term observation of retinal electrical activity in dialyzed and renal transplantation patients

The electroretinographic (ERG) intensity-response function was evaluated in 90 patients subjected to regular dialysis treatment (RDT) and in 27 patients after renal transplantation. Using a logistic equation, three parameters for each set of ERG curves were computed: M, the retinal sensitivity; S, the slope; and A, the maximum attainable potential amplitude. A statistically significant decrease of the A and S values of both the b and a waves in the course of RDT was found. After approximately 6 years of RDT, the frequency of patients with pathological A and S values amounted to 94.6% (b wave) and 80.4% (a wave). On the other hand, renal transplantation was accompanied by a tendency to normalize the original pathological values of the ERG parameters. Changes of electrical retinal activity could contribute to the evaluation of the state of compensation in dialyzed patients.