Title of Article: Subthreshold Nano-Second Laser Treatment and Age-Related Macular Degeneration
What are the key takeaway points from this article?
Apart from lifestyle modifications and dietary supplements, there are no targeted treatments to slow the progression from the early stages of age-related macular degeneration (AMD) to advanced disease. While nanosecond laser is not yet a recognised intervention for AMD, this literature review demonstrates that it may offer an intervention where there currently is none.
An initial human pilot study was conducted consisting of 108 participants with large drusen (>125μm; meeting the definition of intermediate AMD) with best corrected visual acuity (BCVA) >20/63. The study was split into a control group (58 participants) and a treatment group (50 participants) that received one session of 12 spots of subthreshold 2RT® laser at an average of 0.24mJ in one eye. Drusen were assessed at 6mo, 12mo, and 2 years. After 12 months, 40% of the eyes receiving 2RT® had a statistically significant reduction in drusen area compared to baseline which differed from only a 5% reduction in the control group (p < 0.001). Furthermore, the effect was maintained over 2 years (in 35% of the treatment eyes). Interestingly, the contralateral eyes in the 2RT® laser group that did not receive laser therapy, also demonstrated a reduction in drusen at 12 months (p = 0.05). However, this was not maintained at the two-year follow up mark. Importantly, this study demonstrated spontaneous resolution of drusen without progression to atrophy 2-years post 2RT® therapy. These results were reinforced by the LEAD clinical trial which had 292 participants and demonstrated that patients without reticular pseudo-drusen (RPD), showed more than a 4-fold reduction in progression to late AMD in the 2RT group compared to control.
Preclinical models have shown that a nanosecond laser (2RT®) can be safely delivered to the retina where it is selectively taken up by retinal pigment epithelium. This treatment shows biological plausibility given our current understanding of AMD pathogenesis. The existing literature provides clinical evidence that supports continued research in the field of subthreshold nanosecond laser delivery as a possible early intervention to slow AMD progression. Further well-conducted, randomised clinical trials are required to determine the efficacy and safety of the 2RT® and of other laser therapies with similar treatment goals.
Publication Date: February 2021
Reference:
Cohn AC, Wu Z, Jobling AI, Fletcher EL, Guymer RH. Subthreshold Nano-Second Laser Treatment and Age-Related Macular Degeneration. J Clin Med. 2021;10(3):484. Published 2021 Jan 28. doi:10.3390/jcm10030484
Summary By: Andrew Robart
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