Glyceryl methacrylate (GMA) hydrogel was used as a vitreous implant in 15 rabbit eyes which have been observed for seven months and are still being followed. The dehydrated gel was placed into the vitreous cavity through a small incision at the pars plana ciliaris. Inside the eye the implant swelled by absorbing available intraocular fluid. The final volume of the hydrogel, which can be calculated in advance, was about 32 times bigger than that of the dry implant. The softness of the GMA hydrogel approximated that of the vitreous gel with refractive index, specific gravity, and permeability to water very close to that of the vitreous body. The implants were well tolerated with little or no inflammatory reaction. No complications were observed to result from the presence of the implant inside the eye.
Daniele S, Refojo MF, Schepens CL, Freeman HM. Glyceryl Methacrylate Hydrogel as a Vitreous ImplantAn Experimental Study. Arch Ophthalmol. 1968;80(1):120-127. doi:10.1001/archopht.1968.00980050122020