In Light of Obtaining Remote Fundus Imaging

In Light of Obtaining Remote Fundus Imaging

June 17, 2022

Optical coherence tomography (OCT) is a non-invasive imaging modality that has revolutionized structural imaging of in vivo biological tissues in ophthalmology by providing images with micrometer scale resolution of the anterior and posterior segments of the eye.

As a result, OCT has become a standard technology employed to manage ocular diseases. Most OCT systems, however, are large tabletop devices exclusively found in imaging rooms at eye care offices.

Additionally, these systems require skilled ophthalmic technicians to operate and align as well as cooperative patients who must be capable of sitting upright and follow directions to use a chinrest and direct their gaze at a fixation target.

Consequently, OCT is not readily accessible for urgent and routine care environments, such as primary care clinics.

Optical coherence tomography (OCT) has become standard of care in the diagnosis and management of a myriad of retinal and optic nerve pathology.

Access to diagnostic equipment and skilled imaging personnel in the after-hours setting is often limited. We examined the utility and diagnostic indications for automated OCT in a high-volume after-hours clinic within an eye institute.

Expanded access to automated OCT in the urgent care setting shows promise for improving the accuracy and timeliness of diagnosis, which can be critical for optimising patient outcomes. OCT also provides clear, immediate documentation of pathology for substantiating medical decision-making.

Optical Coherence Tomography (OCT) systems used in the clinic require patient stabilization and gaze fixation to reduce motion artifacts and align the scanner with the region of interest in the retina.

This limits the use of OCT for uncooperative patients, such as unconscious patients undergoing surgery. By tracking eye location and gaze, and mounting a retinal OCT scanner to a robot, we can automatically align the scanner with the subject’s eye.

Optical coherence tomography (OCT) is a ubiquitous ophthalmic imaging technology. However, currently patients are required to position themselves in chin/forehead rests for stabilization with the system operator in close proximity.

Introducing a robot to the clinic enabled distanced, no-contact imaging of a retina clinic population.

Robotically aligned optical coherence tomography (RA-OCT) can provide high-quality volumetric retinal and optic nerve images of patients in the emergency department (ED), the findings of which correlated well with the clinical examinations, according to pilot study results presented at the Women in Ophthalmology 2021 Summer Symposium.

This technology has the potential to be useful in telemedicine, according to Eun Young (Alice) Choi, MD, and Anthony Kuo, MD, senior author and associate professor of ophthalmology at Duke University School of Medicine in Durham, North Carolina.

Patients who present to the ED with ocular injuries may need to undergo a fundus examination, but there are scenarios in which that need may not be met for various reasons. For example, using RA-OCT may meet that need in remote areas.

In a pilot study, Choi and her colleagues tested the ability of RA-OCT to obtain remote fundus imaging of patients who presented to the Duke University ED with ocular complaints.

Six patients (3 men, 3 women; age range, 24-84 years) were recruited for the study over the course of 6 nonconsecutive days.

Patients who presented with penetrating ocular trauma or loss of blood were excluded. The swept-source OCT machine provided a 32° field of view of the retina, including the fovea and optic nerve head.

Rectangular volumes and full-width B-scans were acquired in triplicate. Thickness maps were generated with semiautomatic segmentation of selected volumes. The ophthalmology resident on call evaluated the patients and documented the imaging findings and diagnosis.

The clinician who operated the RA-OCT during imaging of 2 patients was positioned behind a Plexiglas barrier 6 feet away from the patients. Another 4 patients underwent imaging while the operator was in a separate room that was connected remotely to the RA-OCT via a local network.

A trained reader who was masked to the examination reviewed the OCT images, according to Choi. The investigators reported that the images they obtained were of high quality and agreed with the clinical examinations.

The documented pathologies included drusen and retinal thinning. In cases in which the retinal appeared normal, soft drusen were seen on OCT images.

Although the pathologies imaged in the pilot study were limited to findings in only a few patients, Choi envisions a future for RA-OCT in telemedicine. RA-OCT is an investigational device being used under a research protocol.

The device was developed by Joseph Izatt, PhD, of Duke Biomedical Engineering; Mark Draelos, MD, PhD, of Duke Biomedical Engineering and Surgery; and Ryan McNabb, PhD, of Duke Ophthalmology.

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