The leading causes of low vision and blindness, which include cataract, glaucoma, age-related macular degeneration, corneal dystrophy, and diabetic retinopathy, affect over 40 million Americans and have an estimated annual cost of $25 billion for clinical diagnosis and treatment. The prevalence of visual impairment in adults 40 years and older in the United States is above 3.5% and expected to increase markedly due to population aging. Although several recent studies have demonstrated the utility of intraoperative OCT (iOCT) for verifying completion of surgical goals, real-time iOCT feedback is not currently used to guide ophthalmic surgery because of several fundamental limitations of current-generation iOCT technology: (1) Serial cross-sectional OCT does not provide sufficient spatial position and orientation feedback to guide surgery. (2) Video-rate volumetric OCT trades-off sampling density with field-of-view and consistent alignment of small static OCT fields to regions-of-interest is prohibitively difficult during surgical maneuvers. (3) Co-registration of volumetric OCT data with the surgical field is challenging because fiducials are often confounded by the non-uniform illumination and contrast of surgical microscopy. (4) Real-time volumetric OCT visualization is complex and time-consuming, requiring cross-sectional fly-throughs or computationally expensive renderings that occlude subsurface features. We recently developed multimodal intraoperative spectrally encoded coherence tomography and reflectometry (iSECTR) technologies that allows for simultaneous and intrinsically co-registered en face reflectance and cross- sectional OCT imaging. We hypothesize that (1) imaging data from 4D iSECTR of surgical dynamics will benefit surgical decision-making and lead to improved functional outcomes; and (2) integration of imaging, registration, segmentation, and feedback using heads-up display (HUD) visualization will enhance existing and enable novel surgical maneuvers. We have assembled a multidisciplinary team of engineers and clinicians to perform foundational ex vivo and in vivo imaging studies to (1) quantitatively assess the safety and utility of 4D iSECTR- based surgical feedback; and (2) develop novel technologies, feedback mechanisms, and maneuvers that integrate volumetric iSECTR data for image-guided ophthalmic surgery. Comprehensive 4D imaging of tissue- instrument interaction dynamics (AIM 1) provides unprecedent data on structural changes resulting from surgical manipulation that may be predictive of post-operative functional outcomes and enable image-based interrogation of biomechanics and personalized surgical planning. Real-time surgical visualization and guidance (AIM 2) may improve success rates of conventional surgical interventions as well as next-generation gene and stem cell therapies. Image-guided surgery also may be compatible with robotic-assistance and telemanipulation in wide- ranging surgical specialties outside of ophthalmology. Quantitative analysis of intraoperative imaging performance, utility, and clinical value (AIM 3) will motivate future technology development and clinical adoption.
The incidence of blindness and low vision is expected to increase markedly due to population aging. The standard-of-care in ophthalmic surgery to correct visual impairments is limited by intraoperative visualization methods, which have remained unchanged since the 1920?s. This program investigates the safety and utility of intraoperative spectrally encoded coherence tomography and reflectometry technologies for real-time image- guided surgery and develops novel surgical maneuvers that integrate and utilize volumetric imaging data.
