Endo-tamponade agents are crucial surgical adjuncts for vitreo-retinal surgery. Current clinical agents provide internal tamponade through buoyancy forces requiring the need for prolonged facing down post-operative positioning. Other disadvantages include temporary loss of vision, raised intra-ocular pressure, cataract formation and a need for an additional removal surgery. Therein lies an unmet clinical need to develop alternative biomaterials to overcome these key challenges. We describe a biocompatible and biodegradable thermogelling polymer which provides an internal tamponade effect through surface tension and viscosity. Furthermore, we demonstrate its surgical efficacy in the repair of retinal detachment in a non-human primate model. By three-month post-surgery, the thermogel undergoes biodegradation, and is replaced by a vitreous-like body, thereby mimicking the biophysical needs of the natural vitreous body. In summary, we demonstrate the potential superiority of our thermogel compared to current vitreous tamponade gold standards; and present a significant advancement in the use of biomaterials for vitreo-retinal surgery.