Application of Thermo-setting Gel as Artificial Vitreous

Abstract

Abstract: : Purpose: Intraocular gases and silicone oils are used as intraocular fillers in vitreoretinal surgery. They are all water repellent and are useful as intraocular tamponade. On the other hand, they are not suitable as vitreous substitute with added function as drug delivery system. We injected thermo-setting gel (TG), which has been developed to enhance the effect of glaucoma eye drops, into the vitreous cavity of domestic white rabbit and investigated the result. Methods:We used WTG-127 (Wakamoto Pharmaceutical Co. Ltd.), a TG with improved transparency, for intraocular injection.. After vitrectomy in a domestic white rabbit, we injected 2 ml of WTG-127 into the vitreous cavity. Slit-lump microscopy, indirect ophthalmoscopy, intraocular pressure (IOP) and electroretinogram (ERG) were conducted from 1 day to 1 month after the operation. Results:No corneal opacity, corneal edema, fibrin deposition in anterior chamber, lens opacity, vitreous opacity and rise of IOP were observed throughout the observation period. WTG-127 has good transparency, and did not interfere with fundal examination. No retinal abnormality was observed. ERG showed no reduced amplitude or prolonged latency in the postoperative eye compared with the untreated eye. Conclusions: WTG-127 maintains excellent transparency even after setting at body temperature, and no invasion to intraocular tissues was observed during the short observation period. This material has the potential of becoming a useful artificial vitreous with added function as a drug delivery system.

Keywords: vitreous substitutes • vitreoretinal surgery • animal model