Macular Edema Surgical Treatment

Macular edema (ME) represents a common final pathway of many intraocular and systemic diseases, which characterized by the accumulation of extracellular fluid in Henle’s layer and the inner nuclear layer of the retina. ME can cause severe visual disturbances and be considered to be multifactorial and difficult to treat. It may be most commonly seen following diabetic retinopathy, retinal vascular occlusion, intraocular surgery, uveitis, pigmentary degeneration, and/or vitreoretinal traction syndrome. The pathogenesis of ME involves the interplay of several affected factors, including the breakdown of the inner and outer blood retinal barriers, release of biochemical messengers, tissue hypoxia, retinal circulatory changes, and vitreous traction. Although medications and some other therapeutic methods are effective in some cases, they cannot be the best treatment due to adverse effects or lack of durability. Thus, the role of the vitreous in the development of ME has received attention. Abnormal glycation cross-linking of vitreal collagen has been found in the vitreous of ME cases. The abnormal collagen structure can destabilize the vitreous, leading to traction on the macula [1–7], which may distort the BRB and result in ME. On the other hand, the breakdown of the blood retinal barriers can lead to a high concentration of vasopermeable and chemoattractant factors in the posterior vitreous [8]. This pool of agents can cause cell migration to the posterior hyaloid. Contraction of these cells could lead to macular traction with possible development of a shallow macular detachment and exacerbation of ME [9,10]. (Fig. 1) Thus, we discuss the possibility of surgical treatment for ME in the following.