Experimental Vitreous Substitution

Sammanfattning: Blindness and visual disability are common following vitreoretinal pathologies such as open globe injury, proliferative diabetic retinopathy, and rhegmatogenous retinal detachment (RRD). These conditions often necessitate surgical intervention using vitrectomy with a tamponading vitreous substitute. However, current tamponades are all associated with complications such as inflammation, cataract, glaucoma, and optic nerve atrophy. Translation of new vitreous substitutes into clinical use has proven to be challenging, due to a lack of a comprehensive methodology and numerous requirements; bio-compatibility and clinical.In this thesis, we explore several novel vitreous substitutes using newly developed methods with the ultimate goal of clinical translation.First, in an in vitro adult rat retinal explant culture assay, polyethylene glycol, and Bio-Alcamid® gels provoked retinal degeneration, while a cross-linked hyaluronic acid hydrogel, Healaflow®, matched, and even surpassed the preservation of structure when compared with medium only. Secondly, Healaflow® used as a vitreous substitute in an in vivo rabbit vitrectomy model revealed practical usability and favorable bio- compatibility. In a third study, vitreous substitutes with disparate biocompatibility profiles (silicone oil, Healaflow®, Bio-Alcamid®, and BSS) elicited different patterns of intrinsic and extrinsic retinal inflammation in vivo. Finally, a new rabbit repeat vitrectomy RRD-model revealed excellent tamponading effect of the Healaflow® gel.The combination of the presented in vivo and in vitro methods comprise a new paradigm in translational development of novel vitreous substitutes. Healaflow® stands out as a promising candidate for future clinical use as a vitreous substitute.