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.
Secondary retinal detachment - also known as exudative retinal detachment or serous retinal detachment. It is caused by inflammation, vascular abnormalities or injury which cause fluid to build up under the retina (there is no hole, break or tear). Tractional retinal detachment - an injury, inflammation or neovascularization causes the fibrovascular tissue to pull the sensory retina from the retinal pigment epithelium.