Changes in cone-driven functions after intravitreal aflibercept injections in patients with age-related macular degeneration.

PURPOSE

To determine the changes in the cone-driven functions in patients with age-related macular degeneration (AMD) treated with intravitreal aflibercept.

METHODS

We studied 44 eyes of 44 patients diagnosed with AMD whose mean age was 75 years. The contralateral unaffected eyes served as controls. All patients were initially treated with 3 consecutive monthly intravitreal aflibercept injections and thereafter with bimonthly injections for 12 months. Full-field cone electroretinograms (cone ERGs) were recorded at the baseline and at 3, 6, and 12 months after beginning the intravitreal aflibercept injections. The cone ERGs were elicited by red stimuli on a blue background. The focal macular ERGs (fmERGs) were elicited by 15 degrees white stimulus spot centered on the fovea. The amplitudes of the a- and b-waves, photopic negative response (PhNR), and sum of the oscillatory potentials (ΣOPs, sum of OP1-3 amplitudes) were analyzed. In addition, the implicit times of the a- and b-waves were also analyzed.

RESULTS

The amplitudes and implicit times of all components of the fmERGs were significantly improved compared to the baseline at 3 months after beginning the intravitreal aflibercept injections (P < 0.0005-0.05). The amplitudes of the a-waves and PhNRs were further increased during the maintenance phase (P < 0.005-0.01). On the other hand, the amplitudes of the full-field a-waves and PhNR of the cone ERGs were significantly reduced at 6 and 12 months compared to the baseline.

CONCLUSIONS

The macular function improved continuously during the maintenance phase of the intravitreal aflibercept injections. In contrast, the cone-driven functions of the more peripheral retina decreased with repeated injections suggesting adverse effects of the intravitreal aflibercept injections on the function of the more peripheral normal retina.