Comparison Between an Electronic Mobile Device and Optical Coherence Tomography to Determine Cup-to-disc Ratio

Glaucoma is the second major cause of blindness in the world, lagging only behind cataract. However, unlike cataract, blindness caused by glaucoma is irreversible. Early diagnosis of the disease and progression monitoring is thus essential for proper treatment in order to avoid irreversible blindness. The most common screening exam for glaucoma diagnosis and monitoring is the eye fundus evaluation where Cup-to-Disc ratio (CDR) among other parameters are assessed. This kind of evaluation is performed by ophthalmologists based on their visual perception, requiring not only specific training but also some significant amount of time of eye examination.Objective measurement of CDR involves high cost equipment which in turn requires some specific training in order to use them. Currently, the Optical Coherence Tomography is used as the gold standard for CDR measurement. An OCT exam uses a high cost and complex equipment that most of the time is not affordable for low-income people. This study proposes a portable electronic device that captures eye fundus images, analyzes these images, performs CDR calculation and allows storing these images for further analysis. This low cost and portable device was developed to be used in several health services (public or private) and has low energy consumption, easing its mobility. Moreover, using this device is easy, not requiring any significant learning effort from ophthalmologists. In developing countries where screening programs for early diagnosis of glaucomatous neuropathy are adopted, an ever-growing number of researchers are putting a significant amount of effort to develop cost-benefit solutions that can reach low-income people and remote areas. Objective: This study compared CDR measurements from the portable electronic device (PED) developed by Centro de Informatica da Universidade Federal de Pernambuco to CDR measurements provided by OCT. Methods:This study was a non-inferiority trial with masked data analysis. Individuals ranging from 18 to 60 years from both genders that met the pre-defined criteria were included. This study was carried out in Recife at Clinica Oftalmologica Zona Sul and at Centro de Informatica-UFPE. Using both equipment, 5 vertical cup-to-disc ratio (VCDR) evaluations were performed for each eye of the individuals, under midriatic conditions. Evaluations were done by examiners who did not know previously results obtained from other equipment. Data was collected by the main researcher of this research. This study was approved by the ethics committee before it started and all research members signed the TCLE agreement. The statistical test employed in this study was Pearson Correlation test.