gms | German Medical Science

Objective: Dry age-related macular degeneration (AMD) is a chronic, progressive disease and leading cause of visual dysfunction. The LIGHTSITE III (LT3) study evaluated multiwavelength photobiomodulation (PBM) treatment using the LumiThera Valeda^® Light Delivery System in dry AMD [Valeda]. The LT3B study is an open-label extension of the former trial.

Methods: LT3B (NCT06229665) is an open-label, prospective, multi-center extension study on the continued use of PBM in subjects with dry AMD that participated in the 24-month LT3 study. PBM treatment (Tx) consists of low-level light exposure to selected tissues resulting in positive effects on mitochondrial output and improvement in cellular activity. Subjects are treated with 4 series of multiwavelength PBM (590, 660 and 850 nm) delivered every 4 months over a 13-month period using Valeda. Clinical and imaging outcomes were assessed. Data presented include an interim review of available data extending out from 5 months.

Results: The formal LT3 study results demonstrated a significant improvement in best-corrected visual acuity (BCVA) with a primary endpoint BCVA benefit of +6.2 letters at Month 21 in the PBM group (p=0.0036). The LT3 study supported the FDA authorization in the USA for treatment of dry AMD. The LT3B study enrolled 36 subjects (63 eyes) with dry AMD. In this open-label evaluation, a total of 39 eyes previously received the PBM Tx, 15 eyes received Sham Tx, and 9 eyes were non-study (NS) eyes (No Tx). The average time since the end of LT3 (Month 24) and baseline visits for LT3B was 599 days. LT3B baseline BCVA scores were between 65 and 75 letters across groups (Snellen 20/32 – 20/50) (PBM, 74.8; Sham, 65.9; NS, 68.1). Each group showed vision loss during the interval between the LT3 Month 24 timepoint and the LT3B baseline visit (PBM, -2.1; Sham, -5.7; NS, -2.8). At Month 5, following 2 series of PBM Tx, a BCVA gain was observed in each group with the highest gain in the treatment naïve NS group (PBM, +2.2; Sham, +0.5; NS, +5.1). The PBM group showed a mean gain of 5.5 letters after 8 series of PBM Tx and 1,353 days (3.7 years) from Tx initiation.

Conclusions: The LIGHTSITE IIIB study provides a long-term follow-up in subjects that underwent 2 years of PBM treatment. The study further extends the beneficial impact PBM on BCVA, especially when initiated in early to intermediate dry AMD patients. PBM therapy offers a non-invasive treatment strategy targeting a mitochondrial mechanism for patients with dry AMD to maintain retinal health and slow AMD disease progression.