Webster Dictionary(0.00 / 0 votes)Rate this definition: Freebase(0.00 / 0 votes)Rate this definition: Crenulation or Crenulation cleavage is a texture formed in metamorphic rocks such as phyllite, schist and some gneiss by two or more stress directions resulting in superimposed foliations.
Retinal vein occlusions typically occur in older patients with a history of high blood pressure and atherosclerosis. Other causes of retinal vein occlusion include vasculitis, clotting disorders, and medications such as oral contraceptive pills.
Retina Hole. You are probably wondering what is that and so was my husband. There are several different types of retinal tears caused by a PVD. An operculated hole is one of them. These holes are commonly caused by the vitreous pulling on the retina where the fibers are strongly attached and often occur with a PVD.