Multifocal electroretinography in patients with exudative amd and intravitreal treatment with pegaptanib sodium.

BACKGROUND

To objectively investigate central retinal function in patients with choroidal neovascularization (CNV) due to age-related macular degeneration (AMD) before and after treatment with pegaptanib sodium (PS).

METHODS

Patients with CNV due to exudative AMD received intravitreal injections of 0.3 mg PS every sixth week if angiographic activity was evident. Longitudinal observation included recordings with multifocal electroretinography (mfERG) before the first treatment and before each injection at follow-up intervals.

RESULTS

During the observation period of 30.5 +/- 8 weeks (mean +/- SD) a mean number of 5.3 +/- 1.3 injections were applied. Final mean log(MAR) visual acuity decreased, statistically nonsignificant, from 0.67 +/- 0.3 at baseline to 0.74 +/- 0.16. mfERG recordings in 12 patients after 25 +/- 9 weeks evinced a decrease in response density which was statistically significant in the central 5 degrees . Mean P1-amplitudes of ring 1, 2, and 3 were reduced by 66%, 39% and 30%, respectively. During follow-up, implicit times of the P1 components remained stable within 4% of baseline. In three of four patients with vision loss of 2 lines or more, P1-response amplitudes decreased substantially at least 6 weeks prior vision loss.

CONCLUSION

Treatment with PS resulted in a decrease of central retinal function more obvious in mfERG than in VA longitudinal testing. Good correlations were seen between changes in mean vision and changes in mfERG response density components. As a decline in P1-response amplitudes anteceded vision loss in this study, our results indicate a possible role of mfERG to predict vision loss during intravitreal pharmacotherapy.