Effect of oral photochemotherapy (8-methoxypsoralen + UVA) on the electrophysiologic function of retina.

CONTEXT: Since we had observed electroretinographic (ERG) abnormalities in some patients undergoing photochemotherapy with normal eye examination, we decided to investigate the effects of this therapy on retinal function.

OBJECTIVE

To investigate the effects of oral photochemotherapy (8-methoxypsoralen + Ultraviolet-A) on electrophysiologic function of retina.

MATERIALS AND

METHODS

Patients with vitiligo, psoriasis or eczema were enrolled. Patients with any abnormal eye exam or a positive drug or family history for retinal disease were excluded. Baseline standard ERG was provided with the RETIport32 device. The second ERG was performed 6 months after the first and at least 1 week after the last photochemotherapy session (mean number of sessions: 45 ± 11). The outcome measures were changes in rod response, standard combined response, single-flash cone response, 30-Hz flicker (N1-P1) and oscillatory potentials amplitudes.

RESULTS

Forty patients were enrolled; 20 of them (mean age: 31.1 ± 12 years) completed the study. The mean rod response b-wave amplitude decreased from 88.9 ± 47.5 to 86.4 ± 36.6 and standard combined response b-wave amplitude decreased from 266.52 to 261.85 µV (p = 0.422 and p = 0.968, respectively) and the standard combined response a-wave amplitude increased from 155.4 ± 40.0 at baseline to 165.1 ± 48.4 in the follow-up ERG (p = 0.092). The mean single-flash cone response a-wave amplitude decreased insignificantly in the follow-up ERG trace (34.5 ± 13.7 and 29 ± 15.4, respectively, p = 0.242). The mean single-flash cone response b-wave amplitude showed an insignificant increase (p = 0.087). The amplitudes of 30-Hz flicker wave and oscillatory potentials did not change significantly in the follow-up ERG (p = 0.551 and p = 0.739, respectively).

CONCLUSION

Since no significant change in ERG traces was observed, oral photochemotherapy seems safe for retinal electrophysiologic function.