ABSTRACT In adults and older children, Optical Coherence Tomography (OCT) is the gold standard for diagnosis and management of retinal diseases and systemic disease effects. Most clinical OCT systems are large, tabletop devices that require a compliant subject, capable of positioning in a chin rest and fixating on a target. This typically excludes infants, young children and patients who are unable to cooperate, from OCT imaging. These patients have one of the greatest needs for OCT imaging due to their inability to communicate about disturbance or loss of vision before critical stages of disease development or irrecoverable vision loss occurs. One group in particular are infants at risk for retinopathy of prematurity (ROP) who make up 1.4% of the newborn population. The use of handheld OCT (HH-OCT) systems for point of care imaging has led to significant insights into the development of ROP. However, the clinical adoption of HH-OCT has been limited due to the slow speed, size, and weight of current commercial HH-OCT systems and their limited field of view. While the 40° FOV of most handheld systems is useful for macular imaging, it is insufficient for imaging of the peripheral retina where many pediatric retinal diseases, especially ROP, occur. The overall premise of this proposal is that the development of a highspeed, lightweight, widefield, handheld OCT system will significantly improve the diagnostic utility of HH- OCT for assessment of retinal diseases including those involving the peripheral retina, such as ROP, in I/YC/UC patients. This development will ultimately improve access to care for these patients and reduce the cost of care for these patients. Under NIH SBIR Phase I support (R43-EY033604) Theia Imaging developed the T1-W (widefield) system, a light weight, high speed, contact HH-OCT system with a 110° FOV. The system operates at 300 kHz (9x faster than any commercial handheld), its handpiece weighs 325g, and does not require mydriasis for imaging. Imaging of an adult volunteer shows that the system provides excellent visualization of retinal structures in both the macula and the periphery and en-face projections of retinal vessels demonstrate the ability of the system to image most of zone II in a single acquisition. Under ongoing NIH support (R44-EY032394), Theia is developing and pursuing regulatory clearance for 300 kHz non-contact OCT system. Instead of developing, pursuing regulatory clearance for, and marketing a separate widefield device with the proposed modifications, we will merge the non-contact and widefield systems into the T2-platform. The T2-platform costs of the T2- core, a 300 kHz OCT engine with a modular scan head that accepts a variety of OCT lens bores including non- contact and widefield bores. We believe that the flexibility and cost reduction provided by a modular platform will dramatically improve access to OCT imaging for I/YC/UC patients, as one device can provide imaging for the wide variety of patho...