Macular pigment optical density following lutein scleral iontophoresis in intermediate age-related macular degeneration: A six-month pilot study

PURPOSE: To evaluate the effects of scleral iontophoresis lutein delivery on macular pigment optical density (MPOD), retinal anatomy and function in patients with intermediate age-related macular degeneration (iAMD). METHODS: This prospective pilot study included 15 phakic eyes from patients with iAMD. All participants underwent a single session of trans-scleral iontophoresis with a liposomal lutein formulation. MPOD, central macular thickness (CMT), choroidal vascularity index (CVI) and retinal sensitivity (RS) were assessed at baseline (T0), and at 1 month (T1), 3 months (T2) and 6 months (T3). RESULTS: MPOD showed a significant overall change across time points (χ²=11.01, p=0.012), with significant differences between T1 and T3 (p=0.006) and T2 and T3 (p=0.018). CMT significantly decreased at T3 compared with earlier visits (p≤0.002). RS declined at early time points (T1 and T2 vs T0; p=0.027 and p=0.002, respectively), while CVI exhibited modest reductions by T2 and T3 (p=0.021 and p=0.017). A significant inverse correlation was found between ΔMPOD and ΔRS at T2-T0 (ρ=-0.520, p=0.035). Best-corrected visual acuity remained stable across all visits. CONCLUSIONS: The inverse correlation between MPOD change and RS decline at 3 months raises the possibility that early augmentation of MP may provide a protective functional effect. These data support the short-term feasibility of scleral iontophoresis for targeted lutein delivery.