Ophthalmic Imaging Gets Robotic Enhancement

The development of robotics-driven alignment technology for ophthalmic imaging platforms enables the capture of high-quality images, even in challenging situations, with the added benefit of providing a contactless, operator-free examination, said Anthony Kuo MD.

To date, Dr Kuo and colleagues—including Drs Joseph Izatt, Ryan McNabb, and Pablo Ortiz in the departments of ophthalmology and biomedical engineering at Duke Univer­sity and Dr Mark Draelos (now in the department of robotics at the University of Michigan)—have created and tested a robotically aligning system for posterior segment optical coherence tomography (OCT). However, he said the robotics technology could readily be applied to other imaging devices used in ophthalmology.

The system acquires images without patients having to lean against chin and forehead rests for stabilisation and without needing a trained technician onsite to position the patient and perform the scan. It therefore addresses the needs for equipment sanitisation and physical distancing that came to the forefront during the COVID-19 pandemic.

Using multiple cameras for near real-time tracking com­bined with open and closed loop control of the OCT imager fixed to the robotic arm, the system automatically detects the eye, maintaining proper alignment during the scan by compensating for patient head and eye motion. Dr Kuo highlighted its ability to track and adjust for patient motions by showing its performance in obtaining a quality scan from a patient with retinal pathology despite tremors from Parkin­son’s disease.

“The robotically aligned imaging and motion compensation even allow for rudimentary OCT angiography,” he added.

Other versions of the system can provide verbal instruc­tions and feedback to patients, recognising subjects when they enter the room and directing them to the imaging device. Once the face-tracking camera locates the face, pupil cameras triangulate the pupil location so the OCT beam is properly projected. Then, patients can initiate the scan by depressing a foot pedal. Once completed in the first eye, the system automatically switches to scan the fellow eye. To finish the session, the patient receives instruction to release the foot pedal.

Initially tested in younger adults with healthy retinas, the system was found to perform well by comparing the quanti­tative and qualitative measurements it provided with those acquired through clinician-operated OCT.¹ Additional mod­ifications helped to make the platform more patient-friendly and compatible for use in a clinical research population.

“Changes accounted for the diverse characteristics of patients encountered in daily practice, including differences related to age, ethnicity, and gender,” Dr Kuo said.

Further system testing initially set an examiner in the same room who made sure the scan capture was successful. Realis­ing examiners could perform their functions remotely through a digital connection, subsequent testing placed the examiner at a satellite clinic 10 kilometres from where the imaging was taking place.

Dr Kuo also recommended two additional articles relating to this research for those interested in learning more.^1,2

Dr Kuo spoke at AAO 2023 in San Francisco, US.

1. McNabb R, Ortiz P, Roh KM, et al. “Contactless, autono­mous robotic alignment of optical coherence tomography for in vivo evaluation of diseased retinas,” Res Sq [Preprint]. 2023 Jan 9:rs.3.rs-2371365.

2. Draelos M, Ortiz P, Qian R, Viehland C, McNabb R, Hauser K, Kuo AN, Izatt JA. “Contactless optical coherence tomog­raphy of the eyes of freestanding individuals with a robotic scanner,” Nat Biomed Eng. 2021 Jul; 5(7): 726–736. doi: 10.1038/ s41551-021-00753-6. Epub 2021 Jul 12. PMID: 34253888; PM­CID: PMC9272353.

3. Song A, Roh KM, Lusk JB, Valikodath NG, Lad EM, Draelos M, Ortiz P, Theophanous RG, Limkakeng AT, Izatt JA, Mc­Nabb RP, Kuo AN. “Robotic Optical Coherence Tomography Retinal Imaging for Emergency Department Patients: A Pilot Study for Emergency Physicians’ Diagnostic Performance,” Ann Emerg Med. 2023 Apr; 81(4): 501–508. doi: 10.1016/j. annemergmed.2022.10.016. Epub 2023 Jan 18. PMID: 36669908; PMCID: PMC10038849.

Anthony N Kuo MD is an Associate Professor of Ophthalmology and Assistant Professor of Biomedical Engineering at Duke University, Durham, North Carolina, US. anthony.kuo@duke.edu