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Diabetic Macular Oedema Section Heading Section sub Navigated Laser Therapy for Diabetic Macular Oedema Marcus Kernt, 1 Michael Ulbig, 1 Anselm Kampik 2 and Aljoscha S Neubauer 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 computerised assistance systems to retinal laser photocoagulation treatment. As main benefits over conventional laser, the Navilas system offers high precision and safety and provides additional advantages regarding standardisation of planning, execution, documentation, quality assurance and better overall treatment comfort for the patient. Navigated laser therapy is being used with good success in the treatment of diabetic macular oedema (DMO), retinal vein occlusions (RVO) and fast-pattern navigated panretinal photocoagulation in proliferative diabetic retinopathy (PDR). In centre-involving DMO, 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 oedema, ETDRS, navigated laser therapy, pattern laser, diabetes Disclosure: Marcus Kernt and Aljoscha S Neubauer are scientific consultants to OD-OS GmbH. The remaining authors have no conflicts of interest to declare. Received: 24 October 2013 Accepted: 25 November 2013 Citation: European Ophthalmic Review, 2013;7(2):127–30 Correspondence: Marcus Kernt, Augenklinik der Ludwig-Maximilians-Universität, Mathildenstr. 8, 80336 München, Germany. E: Current Therapy of Retinal Vascular Disease Retinal vascular disorders are commonly found in ophthalmological practice: in addition to hypertensive changes and retinal vein occlusions, diabetic eye disease play a major role. Driven by demographic change and the obesity trend, the prevalence of diabetes has increased steadily over the last years and is likely to rise further. Diabetic retinopathy (DR) and diabetic macular oedema (DMO) are ocular complications of diabetes, where numbers are expected to double by 2030. 1 As opposed to other retinal diseases, DR and DMO frequently affect the working- age population, requiring long-term disease management. To date, DR and especially its manifestation DMO 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 DMO. 5,6 For PDR panretinal laser photocoagulation (PRP) is the method of choice to repress neovascularisation caused by retinal ischaemia and to prevent serious complications. Likewise, for DMO without foveal involvement focal laser has been the gold standard for the last three decades. 6,7 The concept of clinically significant macular oedema (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 oedema greater than one disc area at a distance of one disc diameter of the fovea. 6 Even though the patient still has good vision, immediate action is warranted. Numerous studies have shown that a significant stabilisation of visual acuity can be achieved in patients with CSMO by a single or repeated focal laser treatment. 3,4,7 © TO U CH MED I CA L MED IA 2013 While the exact mechanisms of action of laser photocoagulation in DMO (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 oedema 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 stabilisation 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, it was found that despite these improvements to the original protocol, no significant visual improvement could be reached with conventional laser therapy. This holds true also and especially for clinically significant DMO, where the centre of the eye’s sharpest vision is involved. By contrast, the easy-to-standardise pharmacological therapies such as intravitreal anti-vascular endothelial growth factor (VEGF) injections 127