Stanford University Network for Diagnosis of Retinopathy of Prematurity (SUNDROP): Truly Mobile Teleophthalmology

Malini Veerappan Pasricha

Cassie A. Ludwig

Darius M. Moshfeghi

The Stanford University Network for Diagnosis of Retinopathy of Prematurity (SUNDROP) is a telemedicine-based program for in-hospital screening of infants at high risk for treatment-warranted retinopathy of prematurity (ROP) at 11 neonatal intensive care units (NICUs) in Northern California, Nevada, and Indiana. All screenings are performed by trained NICU nurses using the RetCam family of cameras (Clarity Medical Systems, Pleasanton, CA) and transmitted remotely to a pediatric vitreoretinal surgeon reader (DMM) via synchronization in a HIPAA-compliant fashion with the SUNDROP servers. Images must be interpreted and management determined within 24 hours of examination.^1,2

The remote expert reader was preparing to board his international flight when he received images for 21 NICU patients. This presented a potential problem for the expert reader to transmit results back to the NICU within the 24-hour time allowance. The minimum time delay was 16 hours: flight duration of 10 hour 45 minutes, plus 2 hours for immigration and customs, 2 hours for travel from airport to hotel, and 1 hour for hotel check-in to remote computer login. One solution would be to tap into a backup reader, but like many other institutions with few pediatric retina specialists, this was not an option.

However, upon reaching a cruising altitude of 30,000 feet, the reader connected to the Wi-Fi on his laptop, remotely logged into the secure server with the Stanford virtual private network (VPN) and began grading images using the proprietary viewer under a laptop privacy screen. VPN extends a private network (the health care system network in the current scenario) across a public internet connection, allowing the user to send and receive data as if they were connected to the private network. This gives the user the security of the private network, thus maintaining the privacy of patient data in the case of clinical care. Despite significant delays due to internet coverage, the reader was able to interpret all 321 images for 21 patients and enter results into the secure data system within 3 hours and 20 minutes.

Recently, the expert reader was able to perform gradings using his tethered phone internationally while traveling in a taxi and using the VPN connection. Although tele-ophthalmology is not a novel concept, neither air grading nor mobile grading had previously been possible due to connectivity and bandwidth constraints.

The goal of tele-ROP screening is to provide timely assessment of high-risk ROP babies. Several growing barriers to screening are decentralization of NICUs, low reimbursement, and high ROP malpractice.³ In addition, changes in the Joint Statement recommendations increased the number of infants eligible for screening and prolonged screening periods (earlier start, later termination), increasing utilization of screening services.¹ Therefore, we must enhance accessibility of tele-ROP screening to providers. Expanding current protocols to include in-sky service may help.

Successful application of in-flight teleophthalmology requires personnel training, high-quality image acquisition, and secure transfer and data storage. Internet coverage and laptop privacy screens are additional considerations. Seven major U.S. airlines offer Wi-Fi, but availability in-flight depends on aircraft model and powering equipment.

Wi-Fi speeds are lacking. At the time of writing, Delta and Virgin America clock in-flight speeds at 15 megabytes per second (Mpbs); Jetblue at 12 Mpbs; Southwest at 10 Mpbs; and Alaska, American, and United at 9.8 Mpbs; this is compared to AT&T and Xfinity's speeds of 1,000 Mbps in Palo Alto, California.⁴

Other limitations of this paradigm include flights that are not equipped with Wi-Fi capabilities or flights that have an unexpected outage. Personal device associated issues are another limitation, such as insufficient device battery and hardware/software glitches. The use of alternative devices, such as phones or handheld tablets, has not been studied for comparative accuracy.

Traditionally, in-flight doctoring was limited to basic management of in-flight medical emergencies.⁵ With increasing connectivity, in-sky continuation of daily physician responsibilities is now possible. If today we can diagnose critical ophthalmic conditions from a laptop at 30,000 feet, tomorrow holds a bright future.