Pathogenic mechanisms in proliferative vitreoretinopathy

Landmarks in the development of treatment of retinal detachment include the recognition of the significance of retinal breaks that resulted in the distinction between rhegmatogenous retinal detachment (RRD) and exudative retinal detachment, the development of indirect ophthalmoscopy and scleral depression that allow better visualization of the peripheral area of the retina and better identification of retinal breaks, the recognition of the need to seal all retinal breaks, and the realization that vitreous traction is the major underlying cause of retinal tears and RRD. Scleral buckling procedures combine retinopexy to provide a scar around retinal breaks to seal them and scleral indentation to neutralize vitreous traction; they provided the first effective treatment of RRD. As surgeons gained experience with scleral buckling, they became aware that some RRDs, particularly those with fixed folds and/or a funnel configuration, often could not be repaired using this approach. It was thought that excessive vitreous traction was at fault, and the condition was called 'massive vitreous retraction.