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Posterior Segment Diabetic Macular Edema Navigated Laser Therapy for Diabetic Macular Edema Marcus Kernt, MD, 1 Michael Ulbig, MD, 1 Anselm Kampik, MD 2 and Aljoscha S Neubauer, MD 1 1. Consultant and Retina Specialist, Department of Ophthalmology; 2. Head of Department of Ophthalmology, Ludwig-Maximilians-University of Munich, Germany Abstract Navigated laser therapy introduces computerized assistance systems to retinal laser photocoagulation treatment. The Navilas system offers high precision and safety and provides additional advantages regarding standardization of planning, execution, documentation, quality assurance, and better overall treatment comfort for the patient as main benefits over conventional laser. Navigated laser therapy is being used with good success in the treatment of diabetic macular edema (DME), retinal vein occlusions (RVO), and fast-pattern navigated panretinal photocoagulation in proliferative diabetic retinopathy (PDR). In center-involving DME, a combination of anti-vascular endothelial growth factor (VEGF) and macular laser may provide advantages over anti- VEGF monotherapy. In terms of navigated laser therapy, recent study data from our clinic and other institutions indicate that combined initial anti-VEGF and navigated macular laser therapy allows treatment success to be achieved and maintained with a significantly reduced number of interventions. Keywords Diabetic retinopathy, macular edema, ETDRS, navigated laser therapy, pattern laser, diabetes Disclosure: Marcus Kernt, MD, and Aljoscha S Neubauer, MD, are scientific consultants to OD-OS GmbH. The remaining authors have no conflicts of interest to declare. Received: October 24, 2013 Accepted: November 25, 2013 Citation: US Ophthalmic Review, 2014;7(1):59–62 Correspondence: Marcus Kernt, MD, Augenklinik der Ludwig-Maximilians-Universität, Mathildenstr. 8, 80336 München, Germany. E: marcus.kernt@med.uni-muenchen.de Current Therapy of Retinal Vascular Disease Retinal vascular disorders are commonly found in ophthalmologic practice: in addition to hypertensive changes and retinal vein occlusions, diabetic eye disease plays a major role. Driven by demographic change and the obesity trend, the prevalence of diabetes has increased steadily recently and is likely to rise further. Diabetic retinopathy (DR) and diabetic macular edema (DME) are ocular complications of diabetes, where numbers are expected to double by 2030. 1 As opposed to other retinal diseases, DR and DME frequently affect the working-age population, requiring long-term disease management. To date, DR and especially its manifestation DME is the main cause of severe visual impairment and blindness. 1–4 For many years, laser photocoagulation has been the mainstay in the treatment of proliferative DR (PDR) and DME. 5,6 For PDR panretinal laser photocoagulation (PRP) is the method of choice to repress neovascularization caused by retinal ischemia and to prevent serious complications. Likewise, for DME without foveal involvement focal laser has been the gold standard for the last 3 decades. 6,7 The concept of clinically significant macular edema (CSMO) was introduced by the Early Treatment Diabetic Retinopathy Study (ETDRS), describing a thickening of the retina and/or hard exudates within a distance of 500 µm from the fovea or a zone of edema greater than one disk area at a distance of one disk diameter of the fovea. 6 Even though the patient still has good vision, immediate action is warranted. Numerous studies have shown that © TO U C H M ED IC A L MED IA 2014 a significant stabilization of visual acuity can be achieved in patients with CSMO by a single or repeated focal laser treatment. 3,4,7 While the exact mechanisms of action of laser photocoagulation in DME (focal or modified grid laser photocoagulation) are not fully understood, it seems clear that extensive tissue scarring is not the primary aim as it is in laser retinopexy or panretinal laser treatment for PDR. It has been postulated that a major goal of macular laser therapy is to solve leakage arising from macular vessels by photocoagulating photoreceptors and it is believed that, in macular laser treatment, photocoagulation of photoreceptor outer segments results in sealing of the blood vessels in the area of highest visual acuity and the subsequent reduced oxygen demand of the outer retina helps reduce retinal hypoxia. 8–10 In addition, increased oxygen tension in the inner retina helps to decrease tissue edema and improve vision by autoregulatory vasoconstriction and reduced hydrostatic pressure in the capillaries and venules. 8,10 With a delayed onset-of-action, treatment success after macular laser photocoagulation can be assessed at the earliest 3 months after the therapy session. 11 Three to four treatments are typically required when using a slit- lamp-based, manually applied laser to achieve stabilization of vision. 11 On average, only limited visual gains can be expected. 6 Over the years, the original ETDRS laser protocol was steadily adjusted and improved, leading to the modified ETDRS protocol used for example in the more recent studies of the Diabetic Retinopathy Clinical Research Network (DRCRnet). 8 However, 59