Handheld optical coherence tomography (OCT) is a useful tool for imaging retinal thickness in infants. But is it a reliable one?
Researchers at Duke University in Durham, North Carolina, found that measurements taken with a handheld spectral-domain OCT (SD-OCT) system match the reproducibility and reliability of those taken with tabletop SD-OCT machines.1 “We are happily surprised by this finding. We were actually expecting less reproducibility with handheld OCTs,” said Xi Chen, MD, PhD. She added, “Many factors could affect measurements in handheld OCT, including—but not limited to—alignment, hand motion, and infant eye movement.” However, those problems did not arise.
Handheld versus tabletop. For this retrospective review, the researchers included 21 unsedated preterm infants whose foveas were imaged with the handheld device (Envisu C2300, Leica/Bioptigen). Those results were compared to 25 adults scanned with tabletop SD-OCT (Leica/Bioptigen).
Central foveal thickness (CFT) measurements were analyzed by both an expert grader and a typical grader (defined as one who was certified but had less experience).
Agreement with some variation. There was excellent agreement between expert and typical graders on measurements from either imaging system. The graders did, however, find a greater range in infant CFT measurements compared with adults. This was expected because of foveal changes during development. In premature infants, the fovea is shallow, the retinal layers are thin, and there is a lack of photoreceptor sublayers. As the fovea matures, it deepens and the retinal layers thicken. Despite these distinctions in the developing eye, it was notable how reproducible CFT measurements were, Dr. Chen said.
Multiple applications. The results have implications for clinical use as well as for studies, particularly when evaluating infants, uncooperative children, and bedridden adults.
At Duke, pediatric ophthalmologists and pediatric retina specialists have become more reliant on handheld SD-OCT to evaluate the retina and optic nerve in infants and young children, both in the clinic and the OR.
On another front, a prospective study is underway comparing handheld and tabletop instruments in healthy adult volunteers. Handheld instruments could be used in adults who are bedbound or in the ICU as well as in those who otherwise cannot cooperate or follow instructions.
Regarding the current study, Dr. Chen said, “Although it was limited by its retrospective nature, it provided promising results and paved the foundation for future studies evaluating the infant retina.”
1 Wang KL et al. PLoS One. Published online Dec. 11, 2019.
Relevant financial disclosures—Dr. Chen: None.
For full disclosures and the disclosure key, see below.
Full Financial Disclosures
Dr. Chen Research related to this study was funded by a career development award from Research to Prevent Blindness and by the NEI.
Dr. Humayun Allergan: C,L; Duke Eye Center: P; Eyemedix: C,O,P,S; Iridex: P; Johns Hopkins University: P; Lutronic Vision: C,O; MTTR: C,O; Outlook Therapeutics: C; Regenerative Patch Technologies: C,O,P; Replenish: C,O,P; Santen: C,L; Second Sight Medical Products: O,P; USC: E,P.
Dr. Morley None.
Dr. Rose-Nussbaumer None.
||Consultant fee, paid advisory boards, or fees for attending a meeting.
||Employed by a commercial company.
||Lecture fees or honoraria, travel fees or reimbursements when speaking at the invitation of a commercial company.
||Equity ownership/stock options in publicly or privately traded firms, excluding mutual funds.
||Patents and/or royalties for intellectual property.
||Grant support or other financial support to the investigator from all sources, including research support from government agencies (e.g., NIH), foundations, device manufacturers, and/or pharmaceutical companies.
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