Vessey, Kirstan A

Ho, Tracy

Jobling, Andrew I

Mills, Samuel A

Tran, Mai X

Brandli, Alice

Lam, Jackson

Guymer, Robyn H

Fletcher, Erica L

2018-02

<p><b>PURPOSE.</b> Subthreshold, nanosecond pulsed laser treatment shows promise as a treatment for age-related macular degeneration (AMD)" however, the safety profile needs to be robustly examined. The aim of this study was to investigate the effects of laser treatment in humans and mice.</p> <p><b>METHODS.</b> Patients with AMD were treated with nanosecond pulsed laser at subthreshold (no visible retinal effect) energy doses (0.15–0.45 mJ) and retinal sensitivity was assessed with microperimetry. Adult C57BL6J mice were treated at subthreshold (0.065 mJ) and suprathreshold (photoreceptor loss, 0.5 mJ) energy settings. The retinal and vascular responses were analyzed by fundus imaging, histologic assessment, and quantitative PCR.</p> <p><b>RESULTS.</b> Microperimetry analysis showed laser treatment had no effect on retinal sensitivity under treated areas in patients 6 months to 7 years after treatment. In mice, subthreshold laser treatment induced RPE loss at 5 hours, and by 7 days the RPE had retiled. Fundus imaging showed reduced RPE pigmentation but no change in retinal thickness up to 3 months. Electron microscopy revealed changes in melanosomes in the RPE, but Bruch's membrane was intact across the laser regions. Histologic analysis showed normal vasculature and no neovascularization. Suprathreshold laser treatment did not induce changes in angiogenic genes associated with neovascularization. Instead pigment epithelium–derived factor, an antiangiogenic factor, was upregulated.</p> <p><b>CONCLUSIONS.</b> In humans, low-energy, nanosecond pulsed laser treatment is not damaging to local retinal sensitivity. In mice, treatment does not damage Bruch's membrane or induce neovascularization, highlighting a reduced side effect profile of this nanosecond laser when used in a subthreshold manner.</p>

Investigative Ophthalmology & Visual Science, 59(2), p. 731-745

1552-5783

0146-0404

https://hdl.handle.net/1959.11/59275

en

Association for Research in Vision and Ophthalmology

Attribution-NonCommercial-NoDerivatives 4.0 International

Nanosecond Laser Treatment for Age-Related Macular Degeneration Does Not Induce Focal Vision Loss or New Vessel Growth in the Retina

Journal Article

Publication