A Pilot Study Evaluating the Effects of 670 nm Photobiomodulation in Healthy Ageing and Age-Related Macular Degeneration

Abstract

Limited evidence suggests that the application of 670 nm of red light alters the course of aged decline. A previous report on 18 patients showed regression of drusen and improvement in visual functions in patients with intermediate age-related macular degeneration (AMD) by 12 months. We evaluated the functional and structural effects of applying 670 nm light to 31 patients with intermediate AMD and 11 people aged 55 years or above with normal retina. The study eyes were treated daily in the morning with a 670 nm hand-held light source housed in a torch-like tube that emitted energy equivalent to 40 mW/cm2 or 4.8J/ cm2 for 2 min at the viewing aperture. Visual function in terms of best-corrected visual acuity, low luminance visual acuity, scotopic thresholds and rod-intercept time were compared between baseline and 1, 3, 6 and 12 months. Structural changes on optical coherence tomography OCT and colour photographs were also assessed. Five withdrew consent voluntarily due to the intensity of the study visit assessments and two developed neovascular AMD and were excluded from further treatment and the analysis. In normal ageing, there was an improvement in scotopic thresholds in the group with no AMD by 1.77dB (p = 0.03) and no other parameters showed any clinically significant change. In eyes with intermediate AMD, there was no significant improvement in any functional or structural changes at any time point up to 12 months although the compliance was good. This pilot study shows that photobiomodulation with 670 nm has no effect in patients who have already progressed to intermediate AMD.

Photobiomodulation Therapy for Age-Related Macular Degeneration and Diabetic Retinopathy: A Review

“…For this reason, Grewal et al exposed 42 eyes (12 controls, 30 intermediate AMD) to a simple easily reproducible Light Emitting Diode based light source for 120 seconds daily for 12 months. 49 At the end of the study period, no significant anatomic or functional changes were reported.…”

Considerations for the Use of Photobiomodulation in the Treatment of Retinal Diseases

“…The parameters of irradiation used have varied widely, with the variation in the energy density ranging from 0.1 to 25 J/cm 2 , the variation in the irradiance ranging between 8 and 200 mW/cm 2 , and an irradiation duration anywhere between 80 and 250 s ( Table 2 ). However, several studies have reported that PBM plays a negative role in the treatment of progressed AMD, especially accompanied by DME with good visual eyesight [ 32 , 33 , 34 ] ( Table 3 ). Therefore, the progressive stage of retinal diseases is another factor that should be considered when adopting PBM to achieve the best clinical effects.…”

Antiangiogenic activity of photobiomodulation in experimental model using chorioallantoic embryonic membrane of chicken eggs

“…The Food and Drug Administration recently approved the use of photobiomodulation therapy, which showed an effect on age-related macular degeneration (AMD), for clinical studies (8,9) . Although most studies demonstrated the benefits of red light or NIR treatment on experimentally induced retinal damage, the treatment seems to have more activity in the early stages of the disease in clinical practice.…”