The Relationship Between Intraocular Pressure and Macular Edema in Patients With Diabetic Macular Edema

Ocular perfusion pressure (ocular perfusion pressure - OPP), considered the driving force of ocular blood flow. Perfusion pressure is defined as the difference between the artery and vein blood pressure. Because ocular venous pressure is the same or slightly higher than the IOP (intra ocular pressure - IOP), it is common to estimate the OPP as the difference between the arterial blood pressure of IOP. The OPP is critical for diffusion of oxygen, nutrients and metabolic waste from retinal imaging, and decrease it may reduce blood flow to the eye and lead to ischemia or hypoxia. the OPP is controlled by a complex system of Autoregulation. Much has been written about the relationship between the OPP and glaucoma, and agreed that OPP is a low risk factor for this disease. Diabetic macular edema (DME) is the most common cause of vision loss in developed countries the working-age. Many studies were carried out in recent years in an attempt to better understand the pathophysiology of Diabetic macular edema, and there is consensus in the scientific literature that hypertension have a significant effect on Diabetic macular edema. this relationship is much more complex than it seems at first glance. Paques and his team have shown an inverse association between blood pressure to drop night and Diabetic macular edema. LARSEN and his team have shown a similar trend. Hayreh published an article from 2007, where he described the mechanism of improvement of the Diabetic macular edema with discontinuation of hypertensive treatment and thereby raising blood pressure. In this article, Hayreh describes hypoxia as a significant factor in Diabetic macular edema, and demonstrated that treatment of hypoxia by increasing the OPP brought good results in terms of macular thickness If so, it seems that there is not only a link between levels of oxygenation of the retina to Diabetic macular edema, but that improved oxygenation of the retina could lower the levels of macular edema in these patients. If a way were found to improve retinal perfusion, this may lead to an improved oxygenation and reduced edema. The Investigators propose to examine the relationship between macular edema IOP in Participants with Diabetic macular edema, thinking that high IOP means lower OPP, which means increased risk for developing macular edema in this Participants group.