Imaging stability of the portable boom-type ophthalmic OCT in multiple application scenarios

Objective  To evaluate the imaging stability of a portable boom-type ophthalmic ultra-high-resolution optical coherence tomography (OCT) device in multiple application scenarios.

Methods  The boom-type mode and handheld mode of the portable boom-type OCT and the desktop OCT were used to perform three-dimensional imaging tests on three healthy adults undergoing physical examinations at the Zhongshan Ophthalmic Center, Sun Yat-sen University as well as on OEMI-7 model eyes in a sitting position.The same two modes of the portable boom-type OCT were used to perform three-dimensional imaging on four awake non-sedated infants, two sedated infants and four healthy adults in the supine position.The obtained 3D imaging data were processed using a correlation analysis method between adjacent B-scans, and the offset of B-scan in the axial (z-axis) and the fast axis transverse (x-axis) were calculated.The procedures for in vivo human eye experiments followed the Declaration of Helsinki and were approved by the Ethics Committee of Zhongshan Ophthalmic Center, Sun Yat-sen University (No.2020 KYPJ154).All subjects and infant guardians signed the informed consent form.

Results  Compared with the handheld imaging mode, the axial and fast axis lateral motion offsets of the model eye were significantly reduced in the boom-type imaging mode from (124.00±12.49)μm to (48.00±15.87)μm and from (24.00±1.00)μm to (2.67±0.57)μm, respectively ( t=2.932, 4.337; both P<0.001).In both human and model eyes, the axial and fast axis lateral motion offsets of the boom-type mode were significantly lower than in the traditional handheld operation mode (both P<0.001).The axial and lateral motion offsets between the boom-type mode and desk-top OCT imaging were comparable, without significant differences (both P>0.05).In both sedated and awake, non-sedated infants in the supine position, the axial offset of the portable boom-type OCT system was similar to that of the healthy adults, without significant difference in the overall comparison ( P=0.385), and the lateral offsets were higher than those of healthy adults, with statistically significant differences (both P=0.013).There was no significant difference in axial deviation between sedated and non-sedated infants ( P>0.05).The lateral deviation of non-sedated infants was higher than that of sedated infants, though the difference was not statistically significant ( P=0.247).

Conclusions  The portable boom-type OCT system can maintain high-speed, high-resolution imaging performance while achieving imaging stability comparable to traditional desktop OCT systems.It is more suitable for bedside imaging of supine subjects, especially uncooperative infants, and has good clinical application prospects.