Advances in Ophthalmology & Visual System Patients with Diabetic Eye Disease using a Potentially Therapeutic Mask. Do Sufficient Patients Wear the Mask and For How Long? Submit Manuscript | http://medcraveonline.com Abbreviations: DR: Diabetic Retinopathy; DME: Diabetic Macular Edema; OCT: Optical Coherence Tomography; BCVA: Best Corrected Visual Acuity; OLED: Organic LED; CST: Central Subfield Thickness Introduction The retina has one of the highest oxygen consumptions of any tissue in the body [1] and this is mainly due to the photoreceptors and the rods in particular [2]. The rod consumption of oxygen is at its greatest when the retina is dark-adapted [3] and the rods generate dark current. At such time the choroid, the main vascular supply to the photoreceptors, is at its most sluggish and so greater demand is needed from the retinal circulation of the inner retina [4,5]. In diabetic retinopathy, the inner retinal circulation is compromised so the enhanced oxygen requirement of the dark-adapted rods is likely to be a major vascular stress inducer, contributing to the retinal pathology and compromised retinal tissue [6]. In the modern world full dark adaption rarely takes place except during sleep [4]. Thus prevention of rod dark-adaption by use of a night-time light mask is a potentially important home- based, therapeutic option for diabetics with retinopathy and diabetic macular edema (DME). The particular nightly duration of mask wear depends on the patient’s sleep, with the goal being to suppress dark adaptation using the mask for as much time that the patient sleeps as possible. It was shown in a UK safety trial (INSIGHT trial) that both young and elderly normal volunteers and a limited number of patients with diabetic retinopathy wore a light mask nightly for 3 months without major safety issues [7,8] including no significant concerns regarding disruption of circadian rhythms or other sleep issues due to the light. In addition, a proof of concept trial also in the UK, has shown that diabetics with retinopathy wore another type of light mask successfully for 6 months without adverse events [9]. Although this trial (conducted at Kings Hospital, London) was not powered for efficacy, nonetheless it was encouraging that at the outset of the investigation 28 out of 34 trial-completing retinopathy patients had macular cysts and this was reduced to 19 at trial end [9,10]. Similarly INSIGHT’s 15 retinopathy patients had 12 with macular cysts and, of these 10, patients exhibited reduction or elimination of cysts following 3 months of mask wear [8]. For the KINGS trial [9], the light mask contained light emitting diodes (LEDs) that could be recharged from the mains as required. On the other hand, the INSIGHT trial [7,8] used a commercially constructed mask incorporating a pod with Organic LEDs (OLEDs). An OLED is carbon-based technology [11] providing a uniform, glowing illumination for both eyes. Importantly the pod also contains mask wear monitoring so that a precise record of Volume 7 Issue 7 - 2017 1 Vinohrady Teaching Hospital, Czech Republic 2 St Paul’s Eye Unit and the Department of Eye and Vision Science, UK 3 PolyPhotonix Ltd, UK *Corresponding author: Miroslav Veith, Vinohrady Teaching Hospital, Ophthalmology Department, Srobarova 1150-1150, 100 34, Prague 10 Czech Republic, Email: Received: December 01, 2017 | Published: December 18, 2017 Research Article Adv Ophthalmol Vis Syst 2017, 7(7): 00253 Abstract A single centre, prospective, interventional, open label clinical trial was conducted at Vinohrady Eye Department, Prague to evaluate safety and the mask wearing characteristics of patient volunteers who agreed to night-time use of the Noctura 400 light mask for treatment of diabetic retinopathy (DR). Noctura 400 shines green light through closed lids to prevent dark adaption and elevated retinal oxygen consumption while the patient sleeps. A total of 45 patients with advanced non-proliferative or early proliferative DR were recruited and all had diabetic macular oedema (DME). The patients wore the Noctura 400 mask for up to 8 hours per night for six months with measurements of Visual Acuity and Macular thickness at three monthly intervals. The Noctura 400 mask recorded their nightly use. Of the 45 patients who began the trial, 35 (78%) completed the 6 months of nightly mask wear and no major safety issues were identified. Electronic monitoring showed that patients wore the mask for 4.96 +/- 2.97 hours per night and there was no significant lack of persistence over the 6 months trial duration. The average number of missed nights of wear per patient was 34.1+/- 39.0. Visual acuity in these patients showed a modest improvement reversing the visual deterioration noted over 10 months prior to recruitment. Also there was central macular thinning in 38.8% of the completing patients. This commercial device appears to be safe, is worn by the majority of patients with some evidence of benefit even in advanced cases of DR. Keywords: Diabetic retinopathy; Phototherapy; Hypoxia; Sleep mask; Dark adaptation; Retina; Retinopathy; Noctura