A simpler diagnostic algorithm of the Japan Esophageal Society classification for Barrett's esophagus-related superficial neoplasia.

BACKGROUND: We previously developed a Japan Esophageal Society Barrett's Esophagus (JES-BE) magnifying endoscopic classification for superficial BE-related neoplasms (BERN) and validated it in a nationwide multicenter study that followed a diagnostic flow chart based on mucosal and vascular patterns (MP, VP) with nine diagnostic criteria. Our present post hoc analysis aims to further simplify the diagnostic criteria for superficial BERN. METHODS: We used data from our previous study, including 10 reviewers' assessments for 156 images of high-magnifying narrow-band imaging (HM-NBI) (67 dysplastic and 89 non-dysplastic histology). We statistically analyzed the diagnostic performance of each diagnostic criterion of MP (form, size, arrangement, density, and white zone), VP (form, caliber change, location, and greenish thick vessels [GTV]), and all their combinations to achieve a simpler diagnostic algorithm to detect superficial BERN. RESULTS: Diagnostic accuracy values based on the MP of each single criterion or combined criteria showed a marked trend of being higher than those based on VP. In reviewers' assessments of visible MPs, the combination of irregularity for form, size, or white zone had the highest diagnostic performance, with a sensitivity of 87% and a specificity of 91% for dysplastic histology; in the assessments of invisible MPs, GTV had the highest diagnostic performance among the VP of each single criterion and all combinations of two or more criteria (sensitivity, 93%; specificity, 92%). CONCLUSION: The present post hoc analysis suggests the feasibility of further simplifying the diagnostic algorithm of the JES-BE classification. Further studies in a practical setting are required to validate these results.

Introduction to the feature issue on augmented/virtual reality: optics & photonics.

In recent years, augmented/virtual reality (AR/VR) has been attracting attention and investment in both the tech and academic communities, kickstarting a new wave of innovations. In the wake of this momentum, this feature issue was launched to cover the latest advances in this burgeoning field that pertains to optics and photonics. Alongside the 31 research articles being published, this introduction is appended to share with readers the behind-the-issue stories, submission statistics, reading guides, author biographies, and editors' perspectives.

Efficacy of endoscopy under general anesthesia for the detection of synchronous lesions in oro-hypopharyngeal cancer.

BACKGROUND/AIMS: Image-enhanced endoscopy can detect superficial oro-hypopharyngeal squamous cell carcinoma; however, reliable endoscopy of the pharyngeal region is challenging. Endoscopy under general anesthesia during transoral surgery occasionally reveals multiple synchronous lesions that remained undetected on preoperative endoscopy. Therefore, we aimed to determine the lesion detection capability of endoscopy under general anesthesia for superficial oro-hypopharyngeal squamous cell carcinoma. METHODS: This retrospective study included 63 patients who underwent transoral surgery for superficial oropharyngeal squamous cell carcinoma between April 2005 and December 2020. The primary endpoint was to compare the lesion detection capabilities of preoperative endoscopy and endoscopy under general anesthesia. Other endpoints included the comparison of clinicopathological findings between lesions detected using preoperative endoscopy and those newly detected using endoscopy under general anesthesia. RESULTS: Fifty-eight patients (85 lesions) were analyzed. The mean number of lesions per patient detected was 1.17 for preoperative endoscopy and 1.47 for endoscopy under general anesthesia. Endoscopy under general anesthesia helped detect more lesions than preoperative endoscopy did (p<0.001). The lesions that were newly detected on endoscopy under general anesthesia were small and characterized by few changes in color and surface ruggedness. CONCLUSION: Endoscopy under general anesthesia for superficial squamous cell carcinoma is helpful for detecting multiple synchronous lesions.

Macular neovascularisation in a patient with osteogenesis imperfecta exhibiting a novel COL1A1 mutation.

Osteogenesis imperfecta is a congenital disease that presents with varying degrees of connective tissue symptoms, including susceptibility to fracture, growth disorders and hearing loss. Here, we discuss a case in which macular neovascularisation (MNV) resulted in metamorphopsia and decreased visual acuity in a patient with osteogenesis imperfecta exhibiting a novel COL1A1 gene mutation (p.Tyr165*). The patient was a woman in her 30s who reported experiencing distorted vision and diminished visual acuity in her right eye for 1 month as well as a history of hearing loss. Rapid improvements in exudative changes and suppression of relapse were achieved after only two intravitreal injections of ranibizumab. Furthermore, since MNV occurred slightly inferior to the fovea centralis, improvements in visual acuity were better than previously reported. As fragility of Bruch's membrane represents the basis of onset, recurrence and relapse are likely in patients exhibiting MNV, highlighting the need for regular follow-up.

Gradient descent based algorithm of generating phase-only holograms of 3D images.

Fraunhofer diffraction based computer generated holograms (CGH) adopts a Fourier transform lens that reconstructs the image on the Fourier plane. Fresnel diffraction based CGH directly reconstruct the image on the near field, however, the reconstructed image is much farther, which brings difficulty of application. In this paper, a Fresnel transform with the utilization of a Fourier transform lens and a gradient descent based algorithm is proposed to generate holograms of 3D images.

Light field display with near virtual-image mode.

This study proposes a near virtual-image method for a flat-panel light field display using both lens and aperture arrays. The pixels of the flat-panel display are located between the lens array and its focal plane, which increases the viewing zone. The enlarged virtual images of the pixels are generated, and a single enlarged virtual pixel image is transmitted by each aperture of the aperture array. The aperture array also reduces aberrations of the lens array. Because the apertures within the aperture array are wider than the pitch of the pixels, this produces a higher light efficiency than light field displays with aperture arrays. The effectiveness of the proposed technique was verified using constructed light field displays with only horizontal parallax.

Impact of the Concomitant Use of Immunomodulator and a Lower Week 8 Partial Mayo Score on the Persistence of Adalimumab in Refractory Ulcerative Colitis.

Objective Real-world data of adalimumab (ADA) in the treatment of ulcerative colitis (UC) are scarce. We aimed to study the ADA response rates and predictors of response in UC treatment. Methods This observational, prospective and multi-center study assessed the clinical outcome of refractory UC patients treated with ADA who previously had an inadequate response to either conventional therapies or other anti-TNF antibodies or tacrolimus. The primary endpoint was the proportion of UC patients achieving a clinical response and remission at 8 and 52 weeks. We also evaluated the parameters which were associated with a clinical response at 8 and 52 weeks. Results A total of 35 patients were enrolled from 11 centers. The clinical responses at 8 and 52 weeks were 60.0% and 51.4%, respectively. The clinical remission rates at 8 and 52 weeks were 45.7% and 48.6%, respectively. Positive predictors for week 52 response were combination of ADA with immunomodulator (IM) (OR: 27.229; 95% CI; 1.897-390.76; p=0.015) and a week 8 lower partial Mayo score (OR: 0.406; 95% CI; 0.204-0.809; p=0.010). A receiver operation characteristic curve analysis revealed the optimal week 8 partial Mayo score to be 2.5, therefore a partial Mayo score of ≤2 was a positive predictor for the continuation of ADA. No malignancy or death occurred during this study. Conclusion ADA was effective for inducing and maintaining both a clinical response and remission in patients with refractory UC. It remains possible that the concomitant use of IM and a week 8 partial Mayo score of ≤2 may predict the long-term response of ADA.

Diagnostic utility of a novel magnifying endoscopic classification system for superficial Barrett's esophagus-related neoplasms: a nationwide multicenter study.

BACKGROUND: Currently, no classification system using magnification endoscopy for the diagnosis of superficial Barrett's esophagus (BE)-related neoplasia has been widely accepted. This nationwide multicenter study aimed to validate the diagnostic accuracy and reproducibility of the magnification endoscopy classification system, including the diagnostic flowchart developed by the Japan Esophageal Society-Barrett's esophagus working group (JES-BE) for superficial Barrett's esophagus-related neoplasms. METHODS: The JES-BE acquired high-definition magnification narrow-band imaging (HM-NBI) images of non-dysplastic and dysplastic BE from 10 domestic institutions. A total of 186 high-quality HM-NBI images were selected. Thirty images were used for the training phase and 156 for the validation (test) phase. We invited five non-experts and five expert reviewers. In the training phase, the reviewers discussed how to correctly predict the histology based on the JES-BE criteria. In the validation phase, they evaluated whether the criteria accurately predicted the histology results according to the diagnostic flowchart. The validation phase was performed immediately after the training phase and at 6 weeks thereafter. RESULTS: The sensitivity and specificity for all reviewers were 87% and 97%, respectively. Overall accuracy, positive predictive value, and negative predictive value were 91%, 98%, and 83%, respectively. The overall strength of inter-observer and intra-observer agreements for dysplastic histology prediction was κ = 0.77 and κ = 0.83, respectively. No significant difference in diagnostic accuracy and reproducibility between experts and non-experts was found. CONCLUSION: The JES-BE classification system, including the diagnostic flowchart for predicting dysplastic BE, is acceptable and reliable, regardless of the clinician's experience level.

Light field Mirage using multiple flat-panel light field displays.

This study proposes a digital implementation of the conventional Mirage, which uses two parabolic mirrors to produce 360-degree three-dimensional (3D) images of real objects placed inside of it. The two mirrors are replaced with multiple light field displays to generate rays emitted from 3D objects in 360 degrees. We propose two techniques for eliminating repeated 3D images produced by the multiple displays, that is, non-tracking and tracking techniques. The former supports multiple viewers, although the 3D image size is limited. The latter can produce large 3D images, although the number of viewers is limited. The display system of the lower half of the light field Mirage was constructed by using four light field displays to verify the proposed techniques.

Holographic contact lens display that provides focusable images for eyes.

In this paper, we propose a holographic image generation technique for contact lens displays. The proposed technique employs a phase-only spatial light modulator (SLM), a holographic optical element (HOE) backlight, and a polarizer. The proposed holographic technique can generate 3D images apart from the contact lens displays. Therefore, the eyes can focus on the 3D images while simultaneously observing the real scene through the phase-only SLM and the HOE backlight, which provides see-through capability. A bench-top experimental system was constructed to verify the far-distance image generation capability and see-through function.

Approximated super multi-view head-mounted display to reduce visual fatigue.

To reduce the visual fatigue of the head-mounted displays, we propose an approximated super multi-view technique in which multiple viewpoints are generated two-dimensionally with an interval smaller than the pupil diameter using the time multiplexing technique, and left and right virtual images are two-dimensionally shifted in synchronization with the viewpoint generation. The proposed technique enlarges the depth of field of eyes to provide the accommodation-invariant feature so that the vergence-accommodation conflict is mitigated. We constructed an experimental system by using two LED arrays for the viewpoint generation and one LCD panel vibrated by two stepping motors. The proposed technique was then experimentally validated.

Holographic display having a wide viewing zone using a MEMS SLM without pixel pitch reduction.

A one-micron pixel pitch is believed to be required for spatial light modulators (SLMs) to realize holographic displays possessing a wide viewing zone. This study proposes the use of a microelectromechanical systems (MEMS) SLM for not only displaying holographic patterns but also scanning laser beam. During the rotation of MEMS mirrors in the MEMS SLM, the timing of laser pulses illuminating the MEMS SLM is controlled to change the reflection direction of light modulated by the MEMS SLM in order to enlarge the viewing zone. In this technique, the width of the viewing zone depends on the rotation angle of MEMS mirrors, and not on the pitch of pixels (MEMS mirrors). We experimentally demonstrated the enlargement of the viewing zone angle to ∼40° using the MEMS SLM with a pixel pitch of 13.68 µm.

Irregularly branched microvessels as visualized by magnifying endoscopy: a reliable marker for predicting deep submucosal invasion of superficial esophageal squamous cell carcinoma.

Background and study aims Magnifying endoscopy with narrow-band imaging (M-NBI) is reported to be useful in diagnosing invasion depth of superficial esophageal squamous cell carcinoma (SCC), but accurate diagnosis of deep submucosal invasion (SM2) has remained difficult. However, we discovered that irregularly branched microvessels observed with M-NBI are detected in SM2 cancers with high prevalence. Thus, this retrospective study aimed to investigate the diagnostic performance of irregularly branched microvessels as visualized by M-NBI for predicting SM2 cancers. Patients and methods Patients with superficial esophageal SCC lesions that were endoscopically or surgically resected at our hospital between September 2005 and December 2014 were included. Endoscopic findings by M-NBI of these lesions were presented to an experienced endoscopist who was unaware of the histopathological diagnosis and who then judged whether irregularly branched microvessels were present. Using the invasion depth according to postoperative histopathological diagnosis as the gold standard, we determined the diagnostic performance of the presence of irregularly branched microvessels as an indicator for SM2 cancers. Results A total of 302 superficial esophageal SCC lesions (228 patients) were included in the analysis. When irregularly branched microvessels were used as an indicator of SM2 cancers, the diagnostic accuracy was 94.0 % (95 % confidence interval [CI]: 91.1-96.1 %), sensitivity was 79.4 % (95 % CI: 66.6-88.4 %), specificity was 95.9 % (95 % CI: 94.3-97.0 %), positive predictive value was 71.1 % (95 % CI: 59.6-79.1 %), and negative predictive value was 97.3 % (95% CI: 95.7-98.5 %). Conclusions Irregularly branched microvessels may be a reliable M-NBI indicator for the diagnosis of cancers with deep submucosal invasion.

Image quality improvement of random phase-free holograms by addressing the cause of ringing artifacts.

Holographic projectors utilize holography techniques, although there are several barriers to realizing holographic projections. One such challenge is the deterioration of the hologram image quality caused by speckle noise and ringing artifacts. Several methods designed to reduce the speckle noise and ringing artifacts have been proposed. However, these methods require multiple diffraction calculations and a significant amount of computational time. In this paper, we reveal that ringing artifacts are due to object light being recorded on the edge of the hologram and that the high-frequency component of the original image leaks outside of the recording area of the hologram when the random phase-free method is used. Therefore, this study proposes an object light centering method that prevents object light from being recorded on the edge of the hologram and prevents the high-frequency component of the original image from leaking outside the recording area of the hologram, which removes the ringing artifact and extends the random phase-free method to an off-axis hologram.

Super multi-view near-eye display to solve vergence-accommodation conflict.

A super multi-view (SMV) technique is applied to near-eye displays to solve the vergence-accommodation conflict that causes visual fatigue. The proposed SMV near-eye display employs a high-speed spatial light modulator (SLM), a two-dimensional (2D) light source array, and an imaging optics for each eye. The imaging optics produces a virtual image of the SLM and real images of the light sources to generate a 2D array of viewpoints. The SMV images are generated using a time-multiplexing technique: the multiple light sources sequentially emit light while the SLM synchronously displays corresponding parallax images. A monocular experimental system was constructed using a ferroelectric liquid crystal display and an LED array. A full-parallax SMV image generation with 21 viewpoints was demonstrated and a comparison of full-parallax and horizontal parallax SMV images provided.

Flexible retinal image formation by holographic Maxwellian-view display.

The Maxwellian-view display can provide visual information to people with low vision because retinal images can be formed independently of the refractive power of an eye by using rays converging on its pupil. This study presents the holographic Maxwellian-view display, which generates a wavefront converging on the pupil and forming images on the retina. The beam convergent point can be moved electrically in accordance with the pupil movement, and the beam width in the pupil can be changed electrically to control the depth of field of the eye. A compact optical system configuration for the holographic Maxwellian-view display is also proposed. The prototype system was constructed and experimentally tested. Because this holographic technique allows the phase modulation in the pupil, eye aberrations can be corrected; thus, retinal images can be formed for eyes with astigmatism.

Newly developed magnifying endoscopic classification of the Japan Esophageal Society to identify superficial Barrett's esophagus-related neoplasms.

AIM AND METHODS: The Japan Esophageal Society created a working committee group consisting of 11 expert endoscopists and 2 pathologists with expertise in Barrett's esophagus (BE) and esophageal adenocarcinoma. The group developed a consensus-based classification for the diagnosis of superficial BE-related neoplasms using magnifying endoscopy. RESULTS: The classification has three characteristics: simplified, an easily understood classification by incorporating the diagnostic criteria for the early gastric cancer, including the white zone and demarcation line, and the presence of a modified flat pattern corresponding to non-dysplastic histology by adding novel diagnostic criteria. Magnifying endoscopic findings are composed of mucosal and vascular patterns, and are initially classified as "visible" or "invisible." Morphologic features were evaluated for "visible" patterns, and were subsequently rated as "regular" or "irregular," and the histology, non-dysplastic or dysplastic, was predicted. CONCLUSION: We introduce the process and outline of the magnifying endoscopic classification.

Trough level of infliximab is useful for assessing mucosal healing in Crohn's disease: a prospective cohort study.

BACKGROUND/AIMS: Decreased trough levels of infliximab (TLI) and antibodies to infliximab (ATI) are associated with loss of response (LOR) in Crohn's disease. Two prospective studies were conducted to determine whether TLI or ATI better correlates with LOR (Study 1), and whether TLI could become a predictor of mucosal healing (MH) (Study 2). METHODS: Study 1 was conducted in 108 patients, including those with LOR and remission to compare ATI and TLI in discriminating the 2 conditions based on receiver operating characteristic (ROC) curve analyses. Study 2 involved 35 patients who were evaluated endoscopically. RESULTS: In Study 1, there were no differences between the 2 assays in ROC curve analyses; the TLI cutoff value for LOR was 2.6 µg/mL (sensitivity, 70.9%; specificity, 79.2%), and the ATI cutoff value was 4.9 µg/mL (sensitivity, 65.5%; specificity, 67.9%). The AUROC (area under the ROC curve) of TLI was greater than that of ATI. AUROC was useful for discriminating between the 2 conditions. In Study 2, the TLI was significantly higher in the colonic MH group than in the non-MH group (2.7 µg/mL vs. 0.5 µg/mL, P=0.032). CONCLUSIONS: TLI is better than ATI for clinically diagnosing LOR, and a correlation was observed between TLI and colonic MH.

Digital holography and its multidimensional imaging applications: a review.

In this review, we introduce digital holographic techniques and recent progress in multidimensional sensing by using digital holography. Digital holography is an interferometric imaging technique that does not require an imaging lens and can be used to perform simultaneous imaging of multidimensional information, such as three-dimensional structure, dynamics, quantitative phase, multiple wavelengths and polarization state of light. The technique can also obtain a holographic image of nonlinear light and a three-dimensional image of incoherent light with a single-shot exposure. The holographic recording ability of this technique has enabled a variety of applications.

Asymmetric integral imaging system for a see-through three-dimensional display with background imaging function.

A see-through three-dimensional display with variable background imaging function is proposed. The proposed display system is based on integral imaging and consists of three lens arrays and a transparent flat-panel display. An asymmetric alignment of the three lens arrays enables variable background imaging. The background scene situated at any distance from the display system can be imaged at an intended distance from the display system. The possible imaging regions are shown. The proposed technique was experimentally verified using two optical systems that consisted of lens arrays with large and small lens pitches.