Functional outcomes after multiple treatments with ranibizumab in neovascular age-related macular degeneration beyond visual acuity

Beatrix Feigl¹, Amanda Greaves², Brian Brown¹

¹Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia; ²Terrace Eye Center, Ophthalmic Physicians and Surgeons, Brisbane, Australia

Purpose: To evaluate neuroretinal function and anatomical outcomes in patients with neovascular age-related macular degeneration (AMD) after three treatments with ranibizumab.

Design: Observational case reports.

Methods: We investigated visual function in three patients, one female (80 years) and two male (77 and 74 years) with neovascular AMD. Twenty healthy participants served as control group. We measured visual acuity (Bailey-Lovie charts), contrast sensitivity (Pelli-Robson) and neuroretinal function using the multifocal electroretinogram (mfERG). Central macular thickness was evaluated using optical coherence tomography (OCT). Main outcome measures were central and peripheral mfERG peak to trough (N1P1) response density amplitudes and peak (P1) implicit times. All tests were performed before the first treatment (baseline) and after each of the three treatments with intravitreal 0.3 mg ranibizumab.

Results: Visual acuity and contrast sensitivity remained stable or improved. Central macular thickness decreased after three treatments in all three patients. We found no significant change in central and peripheral neuroretinal function in the AMD patients between pre- and posttreatments 2 and 3. Although the mfERG amplitudes in the AMD patients were not significantly reduced compared with the age-similar group at baseline, there was a statistically significant reduction in central and peripheral mfERG amplitudes after three treatments.

Conclusion: Anatomical outcomes and central visual function improved or remained stable in the three AMD patients in concordance with past reports. Further investigations of possible adverse effects of ranibizumab on the central and peripheral neuroretina in large prospective clinical trials are suggested.

Keywords: age-related macular degeneration, optical coherence tomography, OCT, multifocal electroretinogram, multifocal ERG, ranibizumab