ZnPcS(4) selectively localizes to the choriocapillaris and CNV in rats, resulting in the occlusion of laser-induced CNV with minimal damage to the retina tissues. ZnPcS(4) -PDT is a potential new strategy for the treatment of macular degeneration and other human diseases manifesting as CNV.

Purpose: To develop a practical rat model of blood-retinal barrier (BRB) breakdown induced by anterior segment intraocular surgery. Methods: A 27-gauge needle attached to infusion tubing running to a bottle of balanced salt solution was inserted through the limbus into the rat anterior chamber. The pressure of the balanced salt solution was oscillated from 0 to 12 mm Hg above the atmospheric pressure for 30 times. The needle was removed and the anterior chamber was formed. Then the eye was exposed vertically to the light of the operating microscope. The contralateral eye was left untreated. The eyes were applied with ofloxacin ophthalmic solution after surgery. At several time points after surgery, the integrity of the BRB was assessed by fluorescence fundus angiography, optical coherence tomography, immunohistochemical staining for serum albumin and quantitative measurement using Evans blue as a tracer. Results: The extravasation of fluorescein, the increased central retinal thickness, strong staining for albumin in the retina and substantially elevated retinal Evans blue leakage demonstrated BRB breakdown after anterior segment intraocular surgery. On the 1st day after surgery, the model group showed a statistically significant elevation in the retinal Evans blue leakage as compared to the contralateral control group and the normal control group. These increased and reached the peak on the 2nd day after surgery and decreased to the point that there was no significant difference as compared to the contralateral control group and the normal control group on the 7th day after surgery. Conclusions: This study establishes a practical rat model of BRB breakdown induced by anterior segment intraocular surgery.

Purpose: To determine the potential of culture in vitro to alter the human leukocyte antigen (HLA) molecules and costimulatory molecules on human retinal pigment epithelium (RPE). Methods: Pure RPE were isolated and cultured. Two sets of RPE (normal and activated) were used. Activated RPE were obtained by incubating primary cultures of RPE with recombinant human interferon-γ. The expression of HLA molecules and costimulatory molecules on human RPE at different passages after culture in vitro were analyzed quantitatively by flow cytometry. Results: In the process of routine culture on culture flask, the duration of culture in vitro was significantly correlated with the expression of HLA-ABC molecules on the normal RPE and the activated RPE (r = –0.893, p < 0.001 and r = –0.964, p < 0.001 respectively), HLA-DR molecule on the activated RPE (r = –0.901, p < 0.001) and intercellular adhesion molecule-1 on the normal RPE (r = 0.961, p < 0.001). There were no correlations between the duration of culture in vitro andthe expression of HLA-DR molecule on the normal RPE, intercellular adhesion molecule-1 on the activated RPE, B7-1 and B7-2 molecules on the normal RPE and the activated RPE. Conclusions: The chronic rejection is the major immunological rejection following RPE allogeneic graft. Culture in vitro modulation of HLA molecules and costimulatory molecules on RPE may increase lymphocyte infiltration and activation and promote the chronic rejection following allograft RPE transplantation.