A mobile eye unit for screening of diabetic retinopathy and follow‐up of glaucoma in remote locations in northern Finland

Abstract

Editor, I n industrialized countries, the rate of type 2 diabetes mellitus is increasing in an exponential manner. The proper screening of diabetic retinopathy in rapidly increasing patient populations poses major challenges to health care systems. In Finland, the yearly 3% increase in the number of patients receiving glaucoma therapy further burdens the eye health care system (Tuulonen et al. 2009). The Northern Ostrobothnia Hospital District is responsible for the provision of specialized health care services for its population of 382 000. The distances between facilities and patients within this sparsely inhabited hospital district can be > 200 km. In this area, there are over 13 000 diabetes patients and 4400 patients who receive medication for glaucoma (Finnish Social Insurance Institution, 2008). In order to improve the screening of diabetic retinopathy and the follow-up of glaucoma, we developed an alternative way of delivering services by constructing a mobile examination unit, called ‘EyeMo’ (Fig. 1). The Ministry of Health and Social Welfare in Finland supported the financing of the unit. The goal was to produce a way of providing high-volume services (such as high-quality fundus images and visual field examinations) at low unit costs and to guarantee equal access to care. EyeMo is 10.5 m long and 2.5 m wide. It has two examination rooms, one for visual field testing (Humphrey Field Analyzer HFA-740i; Carl Zeiss Meditec, Inc., Dublin, CA, USA) and one for imaging (using a Canon CF-1 mydriatic fundus camera with a Canon 400 digital SLR camera), as well as a waiting area. Two experienced professionals, a nurse and an imaging technician, work in the unit. Since September 2006, over 7000 patients have been seen and about 7700 examinations conducted in EyeMo. In glaucoma patients, the imaging technician takes one wide-angle image per eye from which both the optic nerve head and retinal nerve fibre layer can be evaluated. In diabetes patients, two images are taken, one centred on the optic disc and the other on the macula. The imaging technician records the images, transfers them to the server and forwards the proposed screening schedules to the municipal health authorities. Standard medical equipment, plain technology and teleradiology practices are used in the mobile unit. DICOM (Digital Imaging and Communications in Medicine) standards are used for data transfer of imaging and visual fields. Confidentiality and security are ensured and the data protection guidelines of the hospital are followed. Feedback to the municipal health authorities is transferred electronically. For diabetes patients, the images are pre-screened in the unit by a nurse who has been specially trained for this task. If no diabetic retinopathy is detected, the nurse makes a recommendation for the next screening according to the national clinical practice guideline. If the imaging results are abnormal, the images are forwarded to an ophthalmologist for off-line consultation (about 30% of images). The purpose of this is to ensure that the images are analysed and feedback provided to the municipal health authorities without delay in order to ensure rapid provision of care. The glaucoma patients seen in EyeMo comprise stable glaucoma patients whose follow-up has been judged to be suitable for monitoring by the mobile unit. In EyeMo, the nurse measures the intraocular pressure and compares it with the pre-set target pressure. Visual fields and fundus images are monitored according to the protocol defined in the national clinical practice guidelines (Tuulonen et al. 2003). The glaucoma test results are analysed off-line by a glaucoma specialist. If necessary, online services are available by telephone and the system can be integrated into the hospital’s electronic patient record database through the third generation of telecommunication hardware standards generally used for mobile networking (3G). After two complete operational years, the unit has received glowing feedback, not only from patients, but also from the authorities which bear the costs of the unit (the municipalities). The benefits of the service to patients include faster access to care, regional equality, a reduced need to Fig. 1. The mobile examination unit, designated EyeMo, is equipped with a waiting area and examination rooms for fundus imaging, visual field testing and measurement of intraocular pressure. Acta Ophthalmologica 2009