Subretinal fibrosis, a consequence of choroidal neovascularization (CNV) in age-related macular degeneration (AMD), leads to irreversible vision loss due to excessive accumulation of extracellular matrix (ECM) proteins and fibrotic scarring. Anti-VEGF therapy can reverse neovascularization, but its effect on fibrosis is relatively limited. To reduce the visual impact of the fibrosis that remains after CNV. Our study investigated the use of ROCK inhibitors, fasudil and belumosudil, to treat subretinal fibrosis after CNV. The results confirmed that levels of key fibrotic markers (TGF-β1, fibronectin, vimentin, α-SMA and pMYPT1) were lower after treatment. IMC provided detailed spatial mapping of protein expression, revealing significant changes in structure and cellular composition before and after the treatment. We found that fasudil and belumosudil are effective in attenuating subretinal fibrosis by modulating the ROCK-signaling pathway, reducing ECM remodeling and attenuating the expression of markers associated with fibrosis. We hope to provide a basis for maximizing clinical benefit, focusing on optimizing dose and timing of treatment, exploring combination therapies for future anti-subretinal fibrosis research.

Wound repair in the retina is a complex mechanism, and a deeper understanding of it is necessary for the development of effective treatments to slow down or even prevent degenerative processes leading to photoreceptor loss. In this study, we harnessed a laser-induced retinal degeneration model (532-nm laser photocoagulation with 300 μm spot size, 60 ms duration and 60 mV pulse), enabling a profound molecular elucidation and a comprehensive, prolonged observation of the wound healing sequence in a murine laser-induced degeneration model (C57BL/6J mice, 6–12 weeks) until day 49 post-laser. Our observations included the expression of specific extracellular matrix proteins and myofibroblast activity, along with an analysis of gene expression related to extracellular matrix and adhesion molecules through RNA measurements. Furthermore, the administration of pirfenidone (10 mg/kg via drinking water), an anti-inflammatory and anti-fibrotic compound, was used to modulate scar formation after laser treatment. Our data revealed upregulated collagen expression in late regenerative phases and sustained inflammation in the damaged tissue. Notably, treatment with pirfenidone was found to mitigate scar tissue formation, effectively downregulating collagen production and diminishing the presence of inflammatory markers. However, it did not lead to the regeneration of the photoreceptor layer.

Subretinal fibrosis, a consequence of choroidal neovascularization (CNV) in age-related macular degeneration (AMD), leads to irreversible vision loss due to excessive accumulation of extracellular matrix (ECM) proteins and fibrotic scarring. Anti-VEGF therapy can reverse neovascularization, but its effect on fibrosis is relatively limited. To reduce the visual impact of the fibrosis that remains after CNV. Our study investigated the use of ROCK inhibitors, fasudil and belumosudil, to treat subretinal fibrosis after CNV. The results confirmed that levels of key fibrotic markers (TGF-β1, fibronectin, vimentin, α-SMA and pMYPT1) were lower after treatment. IMC provided detailed spatial mapping of protein expression, revealing significant changes in structure and cellular composition. We found that fasudil and belumosudil are effective in attenuating subretinal fibrosis by modulating the ROCK-signaling pathway, reducing ECM remodeling and attenuating the expression of markers associated with fibrosis. We hope to provide a basis for maximizing clinical benefit, focusing on optimizing dose and timing of treatment, exploring combination therapies for future anti-subretinal fibrosis research.