Abstract: Peripheral ulcerative keratitis (PUK) is an acute destructive disease of the corneal periphery, typically presenting as a crescent-shaped lesion accompanied by corneal epithelial defects, stromal thinning, and inflammatory cell infiltration. The disease is associated with various systemic and local infectious and non-infectious factors, including rheumatoid arthritis, pathogenic microorganism infections (such as bacteria, fungi, viruses), ocular surgery, and ocular trauma. The exact pathogenesis of PUK remains unclear; however, due to the unique anatomical structure of the corneal limbus, high-molecular-weight substances such as immune complexes may preferentially deposit in this region. Through the combined action of T cells, B cells, the complement system, and matrix metalloproteinases, these deposits trigger corneal epithelial destruction and stromal melting, ultimately leading to the development of peripheral ulcerative keratitis.

Key words: Peripheral ulcerative keratitis, Immune complex