Multifocal ERG and Microperimetry Changes in Response to Ranibizumab Treatment of Neovascular AMD: Randomized Phase 2...

Area of Science:

• Ophthalmology
• Retinal Diseases
• Pharmacology

Background:

• Exudative age-related macular degeneration (AMD) is a leading cause of vision loss.
• Ranibizumab is an anti-vascular endothelial growth factor (anti-VEGF) therapy used to treat wet AMD.
• Treatment strategies include monthly injections or pro re nata (PRN) dosing based on disease activity.

Observation:

• A randomized trial compared monthly versus PRN ranibizumab injections in patients with exudative AMD over 12 months.
• High-resolution optical coherence tomography (HR-OCT) guided PRN retreatment based on fluid presence.
• Macular function was evaluated using microperimetry (MP) and multifocal electroretinography (mfERG).

Findings:

• Both monthly and PRN ranibizumab cohorts showed improvements in best-corrected visual acuity (BCVA) and reductions in central foveal thickness (CFT).
• Mean BCVA gains were comparable between groups (PRN: 6.0 ETDRS letters, Monthly: 7.3 ETDRS letters; p=0.68).
• While MP showed significant improvement in mean sensitivity (1.7 dB; p<0.05), mfERG revealed a comparable decrease in N1-P1 response density in both cohorts (p=0.33), suggesting persistent retinal function decline.

Implications:

• Both dosing regimens of ranibizumab are effective in improving visual acuity and retinal anatomy in exudative AMD.
• The study highlights the utility of MP and mfERG in assessing treatment response and retinal health.
• Despite treatment, mfERG findings suggest ongoing retinal function loss, underscoring the need for continued monitoring and potential therapeutic advancements.