Investigation of Neuroprotective Dyes for Macular Hole Repair

Internal limiting membrane (ILM) peeling during vitrectomy could relieve tangential traction on the fovea and associated with successful rate in various macular pathologies, such as macular hole, macular pucker and myopic foveoschisis, especially for macular hole. Macular hole is vision-threatening disease and ILM peeling is one of the standard procedures for its repair. However, ILM is a very thin and transparent membrane on the surface of retina, therefore, it could cause damage on macula and disturb vision while peeling this membrane without staining. The intravitreous injection of dyes has been reported to allow better visualization of ILM and to contribute to safer peeling by providing a clear contrast between the membrane and the remaining retina. Currently, indocyanine green (ICG) dye was shown to stain avidly the internal limiting membrane (ILM). However, numerous reports have raised concerns over its retinal toxicity and phototoxicity. Alternative chemical dyes also been demonstrated their potential toxicity. Furthermore, subretinal dyes have been reported to cause retinal cell degeneration at lower concentrations than vitreous dyes in both humans and experimental animals. The long-term retention of chemical dye is another issue about safety. The ideal dye need to provide high contrast, neuroprotection and even could nutrition the retinal tissue. It could make surgery easier, reduce surgical damage and improve visual acuity afterwards. Most patients can’t regain their vision even after a successful surgery. Thus, there is a great need to develop new safe dyes for effective staining with neuroprotection. In the previous study, we investigated the safety and efficacy of six anthocyanins for ILM staining, all are extracts from the natural plants. We found three of them, included Cyanidin, Peonidin and Luteolinidin are effective and safe dyes for ILM staining. anthocyanins are essential intergradient in our daily food. Some reports also demonstrated intake of anthocyanins is good for retina. In this study, we will investigate the neuroprotective effect of these 3 anthocyanins. The aim of this study was to investigate in vitro and in vivo the neuroprtective effect of these 3 dyes in cell culture, and injected intravitreally or subretinally into rats’ eyes with clinical examination, fluorescein angiography, histology and, transmission electron microscopy (TEM), and electroretinography (ERG). During the experiment, cells will damage by H2O2 and animals will be treat by light toxicity. The pre-clinical results will find out the potentially dyes which have better neuroprotection for ILM peeling in the future clinical applications.

Project ID:PC10207-0317
External Project ID:NSC102-2314-B182-042