Effects of slit lamp-delivered retinal laser photobiomodulation in a rat model of choroidal neovascularization

Exp Eye Res. 2024 Jul:244:109909. doi: 10.1016/j.exer.2024.109909. Epub 2024 May 4.

Abstract

Neovascular age-related macular degeneration, also known as exudative or wet age-related macular degeneration, is the leading cause of blindness in the developed world. Photobiomodulation has the potential to target the up-stream hypoxic and pro-inflammatory drivers of choroidal neovascularization. This study investigated whether photobiomodulation attenuates characteristic pathological features of choroidal neovascularization in a rodent model. Experimental choroidal neovascularization was induced in Brown Norway rats with laser photocoagulation. A custom-designed, slit-lamp-mounted, 670 nm laser was used to administer retinal photobiomodulation every 3 days, beginning 6 days prior to choroidal neovascularization induction and continuing until the animals were killed 14 days later. The effect of photobiomodulation on the size of choroidal neovascular membranes was determined using isolectin-B4 immunohistochemistry and spectral domain-optical coherence tomography. Vascular leakage was determined with fluorescein angiography. The effect of treatment on levels of vascular endothelial growth factor expression was quantified with enzyme-linked immunosorbent assay. Treatment with photobiomodulation was associated with choroidal neovascular membranes that were smaller, had less fluorescein leakage, and a diminished presence of inflammatory cells as compared to sham eyes. These effects were not associated with a statistically significant difference in the level of vascular endothelial growth factor when compared to sham eyes. The data shown herein indicate that photobiomodulation attenuates pathological features of choroidal neovascularization in a rodent model by mechanisms that may be independent of vascular endothelial growth factor.

Keywords: Age-related macular degeneration (AMD); Choroidal neovascularization; Photobiomodulation therapy; Vascular endothelial growth factors; Wet macular degeneration.

MeSH terms

  • Animals
  • Choroidal Neovascularization* / etiology
  • Choroidal Neovascularization* / metabolism
  • Choroidal Neovascularization* / pathology
  • Disease Models, Animal*
  • Enzyme-Linked Immunosorbent Assay
  • Fluorescein Angiography*
  • Immunohistochemistry
  • Laser Coagulation* / methods
  • Low-Level Light Therapy* / methods
  • Male
  • Rats
  • Rats, Inbred BN*
  • Slit Lamp Microscopy
  • Tomography, Optical Coherence*
  • Vascular Endothelial Growth Factor A* / metabolism

Substances

  • Vascular Endothelial Growth Factor A
  • vascular endothelial growth factor A, rat