Particulate matter exposure is associated with mitochondrial stress and extracellular matrix remodeling in scleral fibroblasts.

Environmental particulate matter (PM) exposure has been increasingly implicated in ocular health, yet its effects on scleral structure and fibroblast-related processes remain incompletely understood. In this study, we investigated the impact of PM exposure on scleral tissues and scleral fibroblast-associated features using integrated in vivo and in vitro models. We found that topically applied PM exposure was associated with particle surrogate distribution to ocular tissues and structural alterations in the posterior segment, including scleral thinning and axial elongation. At the cellular level, PM exposure was accompanied by increased oxidative stress, mitochondrial ultrastructural abnormalities, and phenotypic changes in human scleral fibroblasts (HSFs), together with alterations in collagen-related metabolic features. Transcriptomic analyses further revealed differential regulation of pathways related to extracellular matrix organization, mitochondrial metabolism, and cellular stress responses. Collectively, these findings suggest that PM exposure is associated with mitochondrial and extracellular matrix alterations in scleral fibroblasts and may increase scleral structural vulnerability, providing a potential framework for understanding environmental influences on myopia-related ocular remodeling.