Ocular pathogenesis and immune reaction after intravitreal dispase injection in mice

PURPOSE: The purpose of the current study was to examine the ocular pathogenesis and immune reaction in mice after intravitreal dispase injection. METHODS: Three microliters of dispase at a concentration of 0.2 U/μl were injected into the vitreal cavities of 4–6-week-old mice. Hematoxylin and eosin staining, immunofluorescence analysis, and electroretinograms of the eyes were then performed to assess ocular changes, and enzyme-linked immunospot assays and intracellular staining of single-cell suspensions of the spleens were used to detect immune changes during an 8 week observation period. RESULTS: Neutrophils were the main inflammatory infiltrating cells appearing at the anterior chamber. No cluster of differentiation (CD)3+ labeled T cells, F4/80+ labeled macrophages, or CD56+ labeled natural killer cells were found in the vitreal cavities or retinas in dispase-injected mice within 5 days after injection. Proliferative vitreoretinopathy (PVR)-like signs first appeared at 2 weeks, gradually increased thereafter, and reached peak values at 8 weeks. There was a statistically significant difference in b-wave amplitudes between the PVR and saline-control eyes. Enzyme-linked immunospot assays and intracellular staining showed that specific CD4+ and CD8+ labeled T cells were not involved in dispase-injected mice. CONCLUSIONS: Our data show that neutrophils in the anterior chamber and PVR-like signs in the retinas were found, and that specific immune reactions were not involved after intravitreal dispase injection in mice.