This prospective, double-blind, randomized controlled trial aims to evaluate the efficacy and safety of repeated low-level red-light (RLRL) therapy in patients with dry age-related macular degeneration (AMD). The primary objective is to assess the effect of RLRL therapy on visual function in patients with dry AMD, while the secondary objective is to evaluate its safety and tolerability. Seventy-four participants aged 50 years or older with dry AMD will be enrolled and randomly assigned in a 1:1 ratio to either the active RLRL intervention group (using the full device power) or the control group (sham device at 10% power). Group assignments will be masked to both participants and investigators. Participants will administer the treatment at home twice daily (3-minute sessions, with at least a 4-hour interval between sessions) over five consecutive weekdays each month for three months. A video tutorial will guide device usage, with ongoing support from the research team. Before enrollment, participants will undergo a comprehensive assessment, including ocular and family history review, OCT, and fundus photography to confirm eligibility. Evaluations will occur at baseline, 1 month, and 3 months, covering best-corrected visual acuity (BCVA), slit-lamp examination, OCT, OCT angiography (OCTA), fundus autofluorescence (FAF), contrast sensitivity, color vision, electroretinography (ERG), visual-related quality of life (VRQL) questionnaires, and adverse event monitoring. The primary outcome is the mean change in BCVA from baseline to 3 months. Secondary outcomes include changes in central drusen thickness, geographic atrophy (GA) size and progression, choroidal blood flow, contrast sensitivity, ERG responses, and VRQL scores. Given the limited treatment options for dry AMD, which are primarily focused on lifestyle changes and nutritional supplements, this study investigates the potential of RLRL therapy as a novel, non-invasive treatment. The results may address the unmet medical need in dry AMD, potentially slowing disease progression and improving patients' quality of life.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
94
Each participant in the RLRL therapy group will be provided a repeated low-level red-light therapy (RLRL) device, which they are required to use twice daily for 3minutes per session, with a minimum interval of 4 hours between sessions (5 days a week) for three month.
Each participant in the sham group will be provided a sham therapy device, which they are required to use twice daily for 3minutes per session, with a minimum interval of 4 hours between sessions (5 days a week) for three month.
The Hong Kong Polytchnic University
Hong Kong, Hong Kong, China
The mean change in BCVA measured by ETDRS chart
An Early Treatment Diabetic Retinopathy Study (ETDRS) chart (Precision Vision, Villa Park, Illinois, USA) with standard illumination will be used to measure distance visual acuity. Best corrected visual acuity and uncorrected visual acuity will be measured.
Time frame: At 1month and 3 months compared to baseline
Change in central drusen volume measured by optical coherence tomography (OCT)
Spectral-domain OCT (Spectralis OCT; Heidelberg Engineering, Heidelberg, Germany) with 49 parallel B-scan lines will be used to image the study eye. The automated real-time (ART) function will average 16 frames per scan. Measurements will include sub-RPE macular drusen volume within the 6 × 6 mm ETDRS grid and mean central subfield sub-RPE drusen thickness within the central 1-mm ETDRS subfield. Automated and manually corrected segmentation of Bruch's membrane and the RPE, provided by the Heidelberg software, will be used for analysis.
Time frame: At 1month and 3 months compared to baseline
Change in central drusen thickness measured by optical coherence tomography (OCT).
Spectral-domain OCT (Spectralis OCT; Heidelberg Engineering, Heidelberg, Germany) with 49 parallel B-scan lines will be used to image the study eye. The automated real-time (ART) function will average 16 frames per scan. Measurements will include sub-RPE macular drusen volume within the 6 × 6 mm ETDRS grid and mean central subfield sub-RPE drusen thickness within the central 1-mm ETDRS subfield. Automated and manually corrected segmentation of Bruch's membrane and the RPE, provided by the Heidelberg software, will be used for analysis.
Time frame: At 1month and 3 months compared to baseline
Change in retinal sensitivity using microperimetry.
Retinal sensitivity will be assessed using microperimetry performed with the MP-3 microperimeter (NIDEK Co., Ltd., Gamagori, Japan). The device will be used to measure localized retinal sensitivity across the macular region following a standardized testing protocol. Retinal sensitivity thresholds and fixation stability parameters will be recorded and analyzed according to the manufacturer's recommendations.
Time frame: At 1month and 3 months compared to baseline
Outcomes of visual-related quality of life (VRQL) assessed by the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25)
The 25-item National Eye Institute Visual Function Questionnaire (VFQ-25) will be administered to assess VRQL. This instrument covers 12 subscales: general health, general vision, ocular pain, near vision, distance vision, social functioning, role limitations, mental health, dependency, driving, color vision, and peripheral vision. Each subscale score ranges from 0 to 100, with higher scores indicating better self-reported visual function.
Time frame: At 3 months compared to baseline
Size of GA assessed by fundus autofluorescence (FAF) imaging
FAF will be acquired using 488-nm excitation (Spectralis OCT; Heidelberg Engineering, Heidelberg, Germany). GA lesions will be quantified with Region Finder software (Heidelberg Engineering), which provides semi-automated measurement of areas with homogeneous hypoautofluorescence and enables longitudinal assessment of lesion growth.
Time frame: At 1month and 3 months compared to baseline
Change in contrast sensitivity using the Mars Letter Contrast Sensitivity Test
The Mars Letter Contrast Sensitivity Test (Mars Perceptrix, Chappaqua, NY, USA) will be performed under standardized photopic lighting at 50 cm. Participants will read letters sequentially from highest to lowest contrast, with contrast decreasing in 0.04 log unit steps. Testing will continue until two consecutive errors are made. Final scores will be calculated per manufacturer's guidelines and expressed in log contrast sensitivity units.
Time frame: At 1month and 3 months compared to baseline
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