Photocoagulation has been proven safe and effective in the treatment of PDR. In this disorder, the retina becomes ischemic and releases a variety of chemical messengers, most importantly VEGF, that stimulates the growth of new blood vessels, and also markedly increases retinal vascular permeability. The abnormal new vessels, and associated fibrous tissue and macular edema, are major causes of sight-threatening complications in diabetic eye disease.
The retina is translucent tissue that lines the posterior two-thirds of the eye posteriorly to the oraserrata anteriorly. The retina consist of ten layers, arranged in two functional components, pigment and neurosensory with potential space between the two. The nerve fibre layer consists of axons of the ganglion cells, which pass through lamina cribrosa to form the optic nerve.
Optical coherence tomography (OCT) has evolved to become an essential tool in ophthalmology. Its ability to noninvasively image detailed ocular structures and associated microvasculature in vivo with high resolution has revolutionized patient care.