Accuracy and safety verification of ovarian reserve assessment technique for ovarian tissue transplantation using optical coherence tomography in mice ovary

Abstract

Except for histological study, there are currently no suitable techniques available for the detection and identification of primordial follicles in ovary of primary ovarian insufficiency patients who have undetectable AMH levels. Also, the ability to locate and quantify follicles on ovarian cortex strips, without fixation, is valuable for patients who could undergo subsequent successful ovarian tissue transplantation. Although optical coherence tomography (OCT) is a well-established high resolution imaging technique without fixation commonly applied in biomedicine, few reports are available on ovarian tissue imaging. In present study, we established standard OCT follicle images at each developmental stage, including the primordial follicle, and demonstrated the efficacy of OCT to estimate IVF outcome in transplanted mice ovary like ovarian reserve tests. Unfortunately, the current commercial OCT could not be used to accurate follicle count the number of follicles for whole ovary, because the maximum depth of examination was 100 μm. And we demonstrated the safety of OCT examination, it did not affect IVF outcome and birth defect rate, and reproductive ability. Although there is room for improvement, these findings will be first step to bring OCT examination a step closer to clinical application for measuring true ovarian reserve and localizing follicles.

Current state and future possibilities of ovarian tissue transplantation

“…Optical coherence tomography (OCT), which is a non‐invasive and well‐established high‐resolution imaging technique using near‐infrared ray (NIR) examination, is one answer for this issue. We have demonstrated the efficacy and accuracy of this technique to detect and count the number of primordial follicles with murine and human models . Although optimization and developments for clinical application are needed, OCT may lead to a plan based on the numbers of primordial follicles that are contained in ovarian tissue for OTT.…”

Preliminary human application of optical coherence tomography for quantification and localization of primordial follicles aimed at effective ovarian tissue transplantation

“…Detection of primordial follicles on formalin-fixed and embedded human ovarian tissue was reported in 2016 [ 30 ]; this was the first report of detection of primordial follicles in fresh human ovarian tissue with clear OCT images. In 2017, researchers reported the detection of primordial follicles in fresh murine ovaries [ 31 ]. Through non-invasive detection of primordial follicles in fresh human ovarian tissue, localization of primordial follicles can be assessed.…”

“…In particular, a study has been reported on the clinical application of OCT for the detection of malignant cells and to search for primordial follicles in formalin-fixed and embedded ovarian tissue for fertility preservation [ 30 ]. In addition, researchers have recently reported a study using mice ovaries to investigate the possibility of using OCT to assess ovarian reserve [ 31 ].…”

Evaluation of segmentation algorithms for optical coherence tomography images of ovarian tissue

“…Historically, OCT has been successfully applied to biological imaging in the human eye, [6][7][8] the lung, 9,10 the esophagus, 11 the coronary artery, 12,13 in addition to a number of other organs, including the ovaries. [14][15][16][17][18] The physical principle of OCT systems is similar to that of ultrasound, except that OCT systems measure time-resolved backscattered light instead of sound waves. 19 A complicating factor of OCT is the depth dependence of the system performance.…”