Sphere therapy for corneal endothelium deficiency in a rabbit model. Invest Ophthalmol Vis Sci.

PURPOSE. To isolate precursor cells derived from rabbit corneal endothelium (CE) and to use them for the treatment of CE deficiency in a rabbit model. METHODS. A sphere-forming assay was performed to isolate precursor cells from rabbit CE. Immunocytochemistry was used to examine marker expressions of neural and mesenchymal cells in the sphere colonies and their progenies. The pump function of the CE sheet was evaluated by measurement of the potential difference and short circuit current. Precursors obtained from rabbit CE by a sphere-forming assay were injected into the anterior chamber of the eye, after which an eye-down (i.e., CE up) position was maintained for 24 hours to allow attachment by gravitation (sphere eye-down group). The sphere eye-down and control groups, observed for 28 days after surgery, underwent histologic and fluorescence microscopic examinations. RESULTS. Rabbit CE formed primary and secondary sphere colonies. The progeny expressed ␣-smooth muscle actin, nestin, and neural markers and showed a CE-like hexagonal shape and adequate transport activity. Mean corneal thickness in the sphere eye-down group was significantly less than in the other control groups 3, 7, 14, 21, and 28 days (P Ͻ 0.05) after surgery. CE-like hexagonal cells were detected on Descemet's membrane, and corneal edema was substantially suppressed. DiI-labeled cells were spread over the rear corneal surface in the sphere eye-down group only. CONCLUSIONS. Precursors from rabbit CE were isolated by a sphere-forming assay. Rabbit CE-derived sphere therapy is an effective treatment in a rabbit CE deficiency model. (Invest Ophthalmol Vis Sci. 2005;46:3128 -3135

Photodynamic Therapy for Corneal Neovascularization Using Polymeric Micelles Encapsulating Dendrimer

PURPOSE. To investigate the accumulation of new photosensitizers (PSs), dendrimer porphyrin (DP, free DP), and DP encapsulation into polymeric micelles (DP-micelle) and the efficacy of photodynamic therapy (PDT) in an experimental corneal neovascularization model in mice. METHODS. Corneal neovascularization was induced by suturing 10 -0 nylon 1 mm away from the limbal vessel in C57BL6/J mice. To determine the accumulation of free DP and DPmicelle, 10 mg/kg free DP or DP-micelle was administered by intravenous injection 4 days after suture placement. Mice were killed 1, 4, 24, and 168 hours after the injection of PS. Twentyfour hours after the administration of free DP or DP-micelle, mice were treated with a diode laser of 438-nm wavelength at 10 or 50 J/cm 2 . Fluorescein angiography was performed before and 7 days after irradiation, and the area of corneal neovascularization was quantified. RESULTS. Free DP and DP-micelle accumulated in the neovascularized area 1 hour to 24 hours after administration. Fluorescence of DP was weaker than that of DP-micelle. Neither DP-micelle nor DP could be detected in normal limbal vasculature. In the PDT experiments using PS, mean residual rates of corneal neovascularization were 10.1% in the mice treated with DP-micelle and 21.6% in the mice treated with free DP at 10 J/cm 2 (P Ͻ 0.01). At 50 J/cm 2 , mean residual rates of corneal neovascularization were 10.6% in the mice treated with DP-micelle and 13.7% in the mice treated with free DP (P Ͼ 0.05). Although corneal neovascularization in PDT-treated mice exhibited significant regression compared with the control group, significant energy-related vessel regression with increasing laser energy could not be observed. CONCLUSIONS. PDT with DP-micelle and free DP can provide efficacious treatment of corneal neovascularization. (Invest Ophthalmol Vis Sci. 2008;49:894 -899