smartOCT: a low-cost technology to detect and monitor glaucoma in outpatient and primary care centers

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ABSTRACT: Glaucoma is the leading cause of irreversible vision loss globally. Nearly 52.7 million people will be affected in 2020, and that number will grow to ~79.8 million by 2040. The prevalence varies by ethnicity, and the rates of undiagnosed primary open angle glaucoma are alarmingly high (50-85%) in white, black and Latino patients. The challenge in glaucoma detection lies in the asymptomatic nature of its early stage: damage to the optic nerve occurs in an unnoticeable manner that slowly deteriorates the peripheral vision. By the time many patients seek evaluation, the disease has reached a late stage and it is a challenge to preserve the limited remaining central vision. Importantly, early treatment to decrease intraocular pressure (IOP), the only modifiable risk factor for glaucoma, can reduce the rate of progression by 50%, but large population- based studies have confirmed that screening based on IOP is clinically ineffective. Optical coherence tomography (OCT) is central technology for glaucoma screening in standard ophthalmology services. However, the cost and size of clinical OCT systems limits access to the technology by underserved populations, who are simultaneously more likely to be affected with glaucoma-inducing conditions (e.g., diabetes) and less likely to have access to adequate eye care, vision insurance and ability to travel for additional appointments. The availability of low-cost, portable and user-friendly technologies that are deployable in non-specialist outpatient settings (e.g., primary care clinics, endocrinology offices) where high-risk patients present most often is a critical barrier to widespread implementation of effective glaucoma screening programs. We propose a new paradigm for OCT imaging – smartOCT – that leverages the small form factor and ubiquity of smartphones (SPs) to yield a low-cost, lightweight, small-footprint device that facilitates capture, processing, visualization and interpretation of OCT data in outpatient services. Our innovative strategy targets comprehensive integration of OCT with the built-in sensors of smartphones to lower the critical barriers to mass deployment of OCT in clinics. We will demonstrate the feasibility of this technology and clinical workflow through the following specific aims: Aim 1) Finalize a smartOCT prototype for low-cost optic nerve imaging. Aim 2) Confirm the repeatability of smartOCT and comparison to conventional OCT in a pilot clinical study (n = 60). Aim 3) Evaluate the preliminary effectiveness for outpatient services in a pilot study (n = 40) with primary care. If successful, our work will suggest a clear path to broaden access to the OCT technology needed to detect glaucoma and to inspire equip new paradigms and contexts for effective glaucoma screening (e.g., clinics, health fairs, telemedicine). Successful implementation of smartOCT technology will also blaze a trail for the OCT research community to consider new form factors and new scanning mechanisms that can be implicated to study other clinical diseases and/or used in other resource-limited contexts (e.g., global health).