The diabetic macular edema is the main cause of practical blindness in a population in productive age in developer countries. An ophthalmologist usually starts his treatment by a laser coagulation of leasing microaneurysms previously detected by a fluorescein angiogramy.
He is succesful in case of a focal diabetica macular edema. Lower succesfulness of the laser treatmant occurs in case of a difuse macular edema, particularly if a long-term collection of liquid in retina creates a solid plaque of dense exudate directly in the macula.
There are replaced by a glial scar. In this area a loss photoreceptors occurs and low visual acuity is fixed.