Giant Retinal Tears (GRT) are full thickness retinal tears which spread circumferentially for more than 3 clock hours with a posterior vitreous detachment.
They are a challenging case for vitreoretinal surgeons to handle and has a high risk of developing proliferative vitreoretinopathy.
See the excellent article below by Berrocal et al. published in the Journal of Ophthalmic & Vision Research in 2017 on how to manage this condition.
There is also a comprehensive step by step video guide to surgically repair GRT by Dr Hariprasad from Chicago: