Purpose: Photodynamic therapy (PDT) with benzoporphyrin derivative (BPD) may provide a way of treating localized ocular tumors without damaging surrounding structures. Thus, it is important to differentiate among the maximum accumulation times for various structures in the eye. We performed both BPD fluorescence photometry and angiography to determine optimal treatment times for PDT. Methods: Pigmented choro dal tumors in a rabbit model (Retina 14:264, 1994) were used for both biodistribution and angiography. When the tumors reached 2.5-3.0 mm in height, a liposomal preparation of BPD (QLT Photo Therapeutics, Inc., 1mg/kg and 2mg/kg) was injected intravenously, and animals were sacrificed at selected times (15 min, 30 min, 1 h, 3 h, and 24 h). Tumor-bearing eyes were enucleated and frozen in OCT. Cryostat sections were prepared and examined by fluorescence microscopy equipped with appropriate excitation/emission filters. Digital BPD angiography was performed using a Topcon ImageNet H1024 imaging system, a KODAK megaplus camera, and a 50-VT fundus camera. Filters specifically designed for BPD were used. Images were taken at the same time points as in the fluorescence photometry study. Results: Maximal accumulation in the iris, ciliary body, and choroid occurred by 15 min, whereas intratumoral fluorescence peaked between 30-60 min. These findings were confirmed by angiography, which also demonstrated 30-60 min to be the time for highest intratumoral accumulation. Conclusion: Fluorescence photometry confirms our angiographic findings that the optimal treatment time is between 30 min and 1 h following dye injection BPD angiography appears to be a reliable method for studying the biodistribut on of photosensitizers.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience