Chlorophyllin-M: A new substance for photodynamic therapy in the retina and choroid.

Department of Morphology, Faculdade de Medicina do ABC, Santo Andre, Sao Paulo, BrazilBackground and Objective: Chlorophyllin-M is a newchlorophyll-based derivative photosensitive compounddeveloped by our research group with easy laboratorialsynthesis and ideal properties for photodynamic therapy(PDT). It is intended for clinical treatments with simpleand lowcost techniques and reagents.The objectiveof thisstudy is to evaluate if intravenous chlorophyllin-M is ableto deliver a photosensitizer to rabbit retina and rabbitchoroid and promote PDT after ocular irradiation with a660nm LASER.Methods: This is a pre-clinical study. Ten eyes of fivepigmented Californian rabbits were included in the study.The right eyes served as the treatment group, and the lefteyes served as the control group. All eyes had beenophthalmologically evaluated and were considerednormal.Results: Ophthalmic exam with anterior biomicroscopy,dilated fundus examination, and fluorescein angiographyafter the LASER procedure revealed normal anteriorsegment, retinal and choroid vessels occlusion, lumennarrowing, and capillary non-perfusion in the treatedareas,indicatingthatPDTwassuccessfulinthetreatmenteyes group.Conclusion: The results of this pre-clinical study encour-agefuturestudieswiththisnewcompound.Chlorophyllin-M may become a new cost-effective agent in the retinaltherapeutic arsenal. Lasers Surg. Med. 47:421–425, 2015.© 2015 Wiley Periodicals, Inc.Key words: LASER; ocular; neovascularINTRODUCTIONPhotodynamictherapy(PDT)referstothedestructionofdiseased tissue by visible light [1]. PDT is a minimallyinvasive and innovative treatment modality for ocularvascular diseases [2]. It involves the administration of aphotosensitizer (PS), which is activated using light with aspecific wavelength in the presence of molecular oxygen,generating reactive oxygen species (ROS) in target tissuesor cells [3]. The PS is a very important parameter for PDTefficiency.The process of photosensitization in PDT leads to thegeneration of ROS and other radical species (R