Macular Degeneration: Hunt S

Hunt S. · Universitäts-Augenklinik, Ernst-Abbe-Strasse 2, 53127, Bonn, Deutschland. · Ophthalmologe. · Pubmed #17674004 No free full text.

Abstract: According to a recent publication in Nature Medicine an increased dietary intake of omega-3-polyunsaturated fatty acids (PUFA) may protect against the development and progression of retinal neovascularization. The study conducted by L. Smith et al. of the Children's Hospital Boston attracts world-wide attention. In a mouse model of oxygen-induced retinopathy the researchers were able to demonstrate that neonatal mice kept on a "Japanese diet" (i.e. rich in omega-3-PUFA) developed about 50% less retinal neovascularization as compared to mice kept on a "Western diet" (rich in omega-6-PUFA). The results are now being followed-up by a clinical study with the aim to investigate whether prematurely born infants with a high risk of developing ROP may benefit from a diet supplemented with omega-3-PUFA. In addition, the AREDS2-Study which commenced in October 2006 is examining the role of omega-3-PUFA in the development and progression of age-related macular degeneration.

Krohne TU, Hunt S, Holz FG. · Department of Ophthalmology, University of Bonn, Ernst-Abbe-Str. 2, D-53127 Bonn, Germany. · Br J Ophthalmol. · Pubmed #18952645 No free full text.

Abstract: BACKGROUND: Translocation of an autologous retinal pigment epithelium (RPE) sheet under the macula is currently under investigation as a treatment for exudative AMD. Excimer laser-assisted RPE sheet translocation (EST) employs intraocular excimer ablation of excess graft choroidal tissue as a measure to enhance RPE sheet functionality. This study assessed potential adverse effects of excimer irradiation on RPE cells in vitro. METHODS: Human RPE cells (ARPE-19) received 308 nm XeCl excimer laser treatment or 311-312 nm UV-B irradiation. Cell death was visualised with Trypan Blue and quantified by LDH release assay. Apoptosis was detected by DNA fragmentation assay. RESULTS: Laser treatment of 0.175-0.25 J/cm(2) resulted in delayed cell death within 48 h. Time course and dose response paralleled the effect of UV-B irradiation. Cytotoxicity was mediated by apoptosis. Human choroid/Bruch membrane tissue sheets covering the cells during laser irradiation reduced cytotoxicity by 87-95%. CONCLUSION: Cultured human RPE cells are susceptible to apoptotic cell death induced by 308 nm excimer laser irradiation. Absorption by choroid/Bruch membrane tissue can largely prevent the cytotoxic effect. In clinical application, the residual adverse effect of laser ablation on graft RPE cell viability needs to be outweighed by potential advantageous effects on graft survival and functionality to allow for a sensible application of excimer ablation in RPE translocation surgery.