Establishing Monoclonal Gammopathy of Undetermined Significance as an Independent Pre-Disease State of Multiple Myeloma Using Raman Spectroscopy, Dynamical Network Biomarker Theory, and Energy Landscape Analysis.

Multiple myeloma (MM) is a cancer of plasma cells. Normal (NL) cells are considered to pass through a precancerous state, such as monoclonal gammopathy of undetermined significance (MGUS), before transitioning to MM. In the present study, we acquired Raman spectra at three stages-834 NL, 711 MGUS, and 970 MM spectra-and applied the dynamical network biomarker (DNB) theory to these spectra. The DNB analysis identified MGUS as the unstable pre-disease state of MM and extracted Raman shifts at 1149 and 1527-1530 cm-1 as DNB variables. The distribution of DNB scores for each patient showed a significant difference between the mean values for MGUS and MM patients. Furthermore, an energy landscape (EL) analysis showed that the NL and MM stages were likely to become stable states. Raman spectroscopy, the DNB theory, and, complementarily, the EL analysis will be applicable to the identification of the pre-disease state in clinical samples.

Efficacy of cooling therapy and α-lipoic acid derivative against chemotherapy-induced alopecia in an animal model.

Chemotherapy-induced alopecia is frequently induced by various regimens of chemotherapy and has a significant impact on mental health and quality of life. However, the effect of available current treatment for chemotherapy-induced alopecia is not sufficient. This study aimed to clarify the therapeutic effects and mechanism of skin cooling and the antioxidant α-lipoic acid derivative on chemotherapy-induced alopecia. We developed a chemotherapy-induced alopecia model of cyclophosphamide (120 µg/g) using Institute of Cancer Research mice. We used cooling therapy and α-lipoic acid derivative application as the treatments. We compared the alopecia score, hair bulb diameter, insulin-like growth factor-1 level, vascular permeability, and apoptosis between the control and treatment groups. The alopecia score significantly improved in each treatment group compared with that in the cyclophosphamide group. Hair bulb diameter significantly improved in the cyclophosphamide + cooling group compared with that in the cyclophosphamide group. The insulin-like growth factor-1 level and vascular permeability level was significantly retained and suppressed, respectively, in each treatment group compared with that in the cyclophosphamide group. The number of apoptotic cells in the vascular endothelium significantly decreased in the cyclophosphamide + α-lipoic acid derivative group compared with that in the cyclophosphamide group. In conclusion, cooling therapy and α-lipoic acid derivative facilitated recovery from chemotherapy-induced alopecia caused by cyclophosphamide through decreasing vascular permeability.

27-GAUGE PARS PLANA/PLICATA VITRECTOMY FOR PEDIATRIC VITREORETINAL SURGERY.

PURPOSE: To report on the feasibility of 27-gauge (G) vitrectomy for pediatric patients. METHODS: This study is an international, multicenter, retrospective, interventional case series. Participants were patients 17 years or younger who underwent 27-G vitrectomy for various indications. RESULTS: The records of 56 eyes from 47 patients were reviewed. Mean age was 5.7 ± 5.2 years. Diagnoses included retinopathy of prematurity (Stages 3 with vitreous hemorrhage, 4A, 4B, and 5), Terson's syndrome, traumatic macular hole, posterior capsular opacification, endophthalmitis, and others. Instruments used were the 27-G infusion, 27-G vitreous cutter, 27-G light pipe, and 27-G internal limiting membrane forceps. Instrument bending was noted in one (1.8%) case. There were no cases with intraoperative complications, infusion issues, or postoperative endophthalmitis. There were 67/145 (46%) sclerotomies that required suturing, of which most (51/145) were sutured out of precaution. There were four cases (7.1%) that required conversion to a larger gauge and three cases (5.3%) that developed postoperative hypotony. Mean visual acuity improved from logarithm of the minimum angle of resolution 1.32 (20/420) to 0.72 (20/105), after a mean follow-up of 125.1 days (P = 0.01). Anatomic success was achieved in 96.4% of eyes after a single surgery. CONCLUSION: Twenty-seven-gauge vitrectomy was safe and feasible in selected pediatric vitreoretinopathies. Further studies are warranted to examine indications and outcomes.

Practices, Potential, and Perspectives for Detecting Predisease Using Raman Spectroscopy.

Raman spectroscopy shows great potential for practical clinical applications. By analyzing the structure and composition of molecules through real-time, non-destructive measurements of the scattered light from living cells and tissues, it offers valuable insights. The Raman spectral data directly link to the molecular composition of the cells and tissues and provides a "molecular fingerprint" for various disease states. This review focuses on the practical and clinical applications of Raman spectroscopy, especially in the early detection of human diseases. Identifying predisease, which marks the transition from a healthy to a disease state, is crucial for effective interventions to prevent disease onset. Raman spectroscopy can reveal biological processes occurring during the transition states and may eventually detect the molecular dynamics in predisease conditions.

Fatty acid composition of the methylotrophic yeast Komagataella phaffii grown under low- and high-methanol conditions.

In this study, we analysed the intracellular fatty acid profiles of Komagataella phaffii during methylotrophic growth. K. phaffii grown on methanol had significantly lower total fatty acid contents in the cells compared with glucose-grown cells. C18 and C16 fatty acids were the predominant fatty acids in K. phaffii, although the contents of odd-chain fatty acids such as C17 fatty acids were also relatively high. Moreover, the intracellular fatty acid composition of K. phaffii changed in response to not only carbon sources but also methanol concentrations: C17 fatty acids and C18:2 content increased significantly as methanol concentration increased, whereas C18:1 and C18:3 contents were significantly lower in methanol-grown cells. The intracellular content of unidentified compounds (Cn H2n O4 ), on the other hand, was significantly greater in cells grown on methanol. As the intracellular contents of these Cn H2n O4 compounds were significantly higher in a gene-disrupted strain for glutathione peroxidase (gpx1Δ) than in the wild-type strain, we presume that the Cn H2n O4 compounds are fatty acid peroxides. These results indicate that K. phaffii can coordinate intracellular fatty acid composition during methylotrophic growth in order to adapt to high-methanol conditions and that certain fatty acid species such as C17:0, C17:1, C17:2 and C18:2 may be related to the physiological functions by which K. phaffii adapts to high-methanol conditions.

Role of increased vascular permeability in chemotherapy-induced alopecia: In vivo imaging of the hair follicular microenvironment in mice.

Chemotherapy-induced alopecia is one of the most difficult adverse events of cancer treatment for patients. However, it is still unknown why anticancer drugs cause hair loss. We aimed to clarify the mechanism of chemotherapy-induced alopecia in mice using an in vivo imaging technique with a two-photon microscope, which enables observation of the deep reaction in the living body in real time. In this study, ICR mice were injected intraperitoneally with cyclophosphamide (120 µg/g). Changes in the hair bulb morphology, subcutaneous vessel permeability, and vessel density were evaluated by two-photon microscopy and conventional methods. In order to determine whether there is a causal relationship between vascular permeability and hair loss, we combined cyclophosphamide (50 µg/g) with subcutaneous histamine. Using two­photon microscopy and conventional examination, we confirmed that the hair bulbs became smaller, blood vessels around the hair follicle decreased, and vascular permeability increased at 24 hours after cyclophosphamide injection [corrected]. Apoptosis occurred in vascular endothelial cells around the hair follicle. Additionally, hair loss was exacerbated by temporarily enhancing vascular permeability with histamine. In conclusion, cyclophosphamide caused a decrease in vascular density and an increase in vascular permeability, therefore increased vascular permeability might be one of the causes of chemotherapy-induced alopecia.

Fucosyltransferase 8 plays a crucial role in the invasion and metastasis of pancreatic ductal adenocarcinoma.

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer. It is an aggressive malignancy associated with poor prognosis because of recurrence, metastasis, and treatment resistance. Aberrant glycosylation of cancer cells triggers their migration and invasion and is considered one of the most important prognostic cancer biomarkers. The current study aimed to identify glycan alterations and their relationship with the malignant potential of PDAC. METHODS: Using a lectin microarray, we evaluated glycan expression in 62 PDAC samples. Expression of fucosyltransferase 8 (FUT8), the only enzyme catalyzing core fucosylation, was investigated by immunohistochemistry. The role of FUT8 in PDAC invasion and metastasis was confirmed using an in vitro assay and a xenograft peritoneal metastasis mouse model. RESULTS: The microarray data demonstrated that core fucose-binding lectins were significantly higher in carcinoma than in normal pancreatic duct tissues. Similarly, FUT8 protein expression was significantly higher in carcinoma than in normal pancreatic duct tissues. High FUT8 protein expression was significantly associated with lymph-node metastases and relapse-free survival. FUT8 knockdown significantly reduced the invasion in PDAC cell lines and impaired peritoneal metastasis in the xenograft model. CONCLUSIONS: The findings of this study provide evidence that FUT8 plays a pivotal role in PDAC invasion and metastasis and might be a therapeutic target for this disease.

Trefoil factor 2 activation of CXCR4 requires calcium mobilization to drive epithelial repair in gastric organoids.

KEY POINTS: Determining the signalling cascade of epithelial repair, using murine gastric organoids, allows definition of regulatory processes intrinsic to epithelial cells, at the same time as validating and dissecting the signalling cascade with more precision than is possible in vivo Following single cell damage, intracellular calcium selectively increases within cells adjacent to the damage site and is essential for promoting repair. Trefoil factor 2 (TFF2) acts via chemokine C-X-C receptor 4 and epidermal growth factor receptor signalling, including extracellular signal-regulated kinase activation, to drive calcium mobilization and promote gastric repair. Sodium hydrogen exchanger 2, although essential for repair, acts downstream of TFF2 and calcium mobilization. ABSTRACT: The gastric mucosa of the stomach is continually exposed to environmental and physiological stress factors that can cause local epithelial damage. Although much is known about the complex nature of gastric wound repair, the stepwise process that characterizes epithelial restitution remains poorly defined. The present study aimed to determine the effectors that drive gastric epithelial repair using a reductionist culture model. To determine the role of trefoil factor 2 (TFF2) and intracellular calcium (Ca2+ ) mobilization in gastric restitution, gastric organoids were derived from TFF2 knockout (KO) mice and yellow Cameleon-Nano15 (fluorescent calcium reporter) transgenic mice, respectively. Inhibitors and recombinant protein were used to determine the upstream and downstream effectors of gastric restitution following photodamage (PD) to single cells within the gastric organoids. Single cell PD resulted in parallel events of dead cell exfoliation and migration of intact neighbouring cells to restore a continuous epithelium in the damage site. Under normal conditions following PD, Ca2+ levels increased within neighbour migrating cells, peaking at ∼1 min, suggesting localized Ca2+ mobilization at the site of cell protrusion/migration. TFF2 KO organoids exhibit delayed repair; however, this delay can be rescued by the addition of exogenous TFF2. Inhibition of epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK)1/2 or a TFF2 receptor, chemokine C-X-C receptor 4 (CXCR4), resulted in significant delay and dampened Ca2+ mobilization. Inhibition of sodium hydrogen exchanger 2 (NHE2) caused significant delay but did not affect Ca2+ mobilization. A similar delay was observed in NHE2 KO organoids. In TFF2 KO gastric organoids, the addition of exogenous TFF2 in the presence of EGFR or CXCR4 inhibition was unable to rescue repair. The present study demonstrates that intracellular Ca2+ mobilization occurs within gastric epithelial cells adjacent to the damage site to promote repair by mechanisms that involve TFF2 signalling via CXCR4, as well as activation of EGFR and ERK1/2. Furthermore NHE2 is shown to be important for efficient repair and to operate via a mechanism either downstream or independent of calcium mobilization.

Multicenter survey of sutureless 27-gauge vitrectomy for primary rhegmatogenous retinal detachment: a consecutive series of 410 cases.

PURPOSE: To evaluate the surgical outcomes of the 27-gauge (G) vitrectomy system for the treatment of primary rhegmatogenous retinal detachment (RRD). METHODS: This retrospective consecutive series multicenter study involved a total of 410 eyes of 406 patients who underwent 3-port transconjunctival 27G pars plana vitrectomy (PPV) for RRD between November 2014 and December 2016 and who were followed for a minimum of 3 months postoperative. The main outcome measure was primary reattachment, with the secondary outcome measures being final reattachment, improvement of visual acuity (VA), intraocular pressure (IOP), intraoperative and postoperative complications, and surgery time. RESULTS: Of the 410 treated eyes, primary reattachment was achieved in 392 (95.6%) and final reattachment was achieved in 410 (100%). In 226 eyes (55.1%) with macula-on RRD, the mean logarithm of the minimum angle of resolution (logMAR) VA improved from 0.16 ± 0.51 pre-surgery to 0.02 ± 0.14 post-surgery (P = 0.11). In 184 eyes (44.9%) with macula-off RRD, logMAR VA improved from 1.06 ± 0.77 pre-surgery to 0.26 ± 0.35 post-surgery (P < 0.001). Following surgery, the mean IOP was highest at 1 day (15.7 ± 7.0 mmHg) postoperative. In all eyes, surgery was concluded without the use of sutures or the need of conversion to a larger-gauge instrument. Although hypotony was observed in 14 (3.4%) of the 410 treated eyes at 1 day postoperative, it spontaneously resolved within 1 week without additional surgical intervention. No postoperative complications such as infectious endophthalmitis were observed throughout the follow-up period. CONCLUSION: Our findings show that 27G PPV is both safe and effective for the treatment of primary RRD.

Raman Spectroscopic Analysis to Detect Reduced Bone Quality after Sciatic Neurectomy in Mice.

Bone mineral density (BMD) is a commonly used diagnostic indicator for bone fracture risk in osteoporosis. Along with low BMD, bone fragility accounts for reduced bone quality in addition to low BMD, but there is no diagnostic method to directly assess the bone quality. In this study, we investigated changes in bone quality using the Raman spectroscopic technique. Sciatic neurectomy (NX) was performed in male C57/BL6J mice (NX group) as a model of disuse osteoporosis, and sham surgery was used as an experimental control (Sham group). Eight months after surgery, we acquired Raman spectral data from the anterior cortical surface of the proximal tibia. We also performed a BMD measurement and micro-CT measurement to investigate the pathogenesis of osteoporosis. Quantitative analysis based on the Raman peak intensities showed that the carbonate/phosphate ratio and the mineral/matrix ratio were significantly higher in the NX group than in the Sham group. There was direct evidence of alterations in the mineral content associated with mechanical properties of bone. To fully understand the spectral changes, we performed principal component analysis of the spectral dataset, focusing on the matrix content. In conclusion, Raman spectroscopy provides reliable information on chemical changes in both mineral and matrix contents, and it also identifies possible mechanisms of disuse osteoporosis.

Determination of Formaldehyde in Water Samples by High-Performance Liquid Chromatography with Methyl Acetoacetate Derivatization.

A high-performance liquid chromatography method with methyl acetoacetate derivatization via the Hantzsch reaction was developed for the analysis of formaldehyde (HCHO) in several water samples. Under optimized conditions, HCHO was detected within 4 min and was not affected by excessive derivatization reagents. The calibration curve constructed from the peak height of HCHO was linear, with a correlation coefficient of 0.9998. The relative standard deviation of the peak height from ten replicates was 0.29%. The detection and quantitative limits were 0.96 µg/L and 3.16 µg/L, respectively. A recovery test of HCHO was performed to compare the developed method with the official analysis method (DNPH method). The developed method was used to determine the HCHO levels in several water samples (tap water, river water, and waste water).

SURGICAL OUTCOMES OF 27-GAUGE VITRECTOMY FOR A CONSECUTIVE SERIES OF 163 EYES WITH VARIOUS VITREOUS DISEASES.

PURPOSE: To evaluate the safety and efficacy of 27-gauge vitrectomy for various vitreoretinal disorders. METHODS: In this retrospective comparative study, 163 consecutive eyes with various diseases that underwent 27-gauge pars plana vitrectomy with or without ultraspeed transformer by a single surgeon from June 2012 through December 2014 were analyzed in regard to best-corrected visual acuity, intraocular pressure, intraoperative and postoperative complications, and surgery time. RESULTS: In 2 eyes (1.2%), peripheral retina breaks were encountered intraoperatively, yet no other complications were found in those eyes. No cases required larger-gauge vitrectomy. Mean best-corrected visual acuity improved from 20/58 (logarithm of the minimum angle of resolution, 0.46 ± 0.64) preoperatively to 20/32 (logarithm of the minimum angle of resolution, 0.20 ± 0.40) postoperatively (P < 0.001). Mean follow-up was 16.7 months (range, 6-33 months). Intraocular pressure remained stable throughout the postoperative course. Hypotony was seen in 15 eyes (9.2%) at 1-day postoperative, yet that spontaneously improved within 1 week. No case of retinal detachment or endophthalmitis was recorded. In macular surgeries, such as idiopathic epiretinal membrane and macular hole combined with cataract surgery, the mean surgery time was 32.1 ± 6.9 minutes with ultraspeed transformer (n = 38) and 37.1 ± 7.7 minutes without ultraspeed transformer (n = 40) (P = 0.004). CONCLUSION: The 27-gauge pars plana vitrectomy was found to be safe and effective for treating various vitreoretinal disorders.

Altered Gene Expression of RNF34 and PACAP Possibly Involved in Mechanism of Exercise-Induced Analgesia for Neuropathic Pain in Rats.

Despite the availability of several modalities of treatment, including surgery, pharmacological agents, and nerve blocks, neuropathic pain is often unresponsive and sometimes progresses to intractable chronic pain. Although exercise therapy is a candidate for treatment of neuropathic pain, the mechanism underlying its efficacy has not been elucidated. To clarify the molecular mechanism for pain relief induced by exercise, we measured Rnf34 and Pacap mRNA levels in the spinal cord dorsal horn of SNL rats, a model of neuropathic pain. SNL model rats exhibited stable mechanical hyperalgesia for at least 6 weeks. When the rats were forced to exercise on a treadmill, mechanical and thermal hyperalgesia were significantly ameliorated compared with the non-exercise group. Accordingly, gene expression level of Rnf34 and Pacap were also significantly altered in the time course analysis after surgery. These results suggest that exercise therapy possibly involves pain relief in SNL rats by suppressing Rnf34 and Pacap expression in the spinal cord.

Evaluation of Injured Axons Using Two-Photon Excited Fluorescence Microscopy after Spinal Cord Contusion Injury in YFP-H Line Mice.

Elucidation of the process of degeneration of injured axons is important for the development of therapeutic modules for the treatment of spinal cord injuries. The aim of this study was to establish a method for time-lapse observation of injured axons in living animals after spinal cord contusion injury. YFP (yellow fluorescent protein)-H transgenic mice, which we used in this study, express fluorescence in their nerve fibers. Contusion damage to the spinal cord at the 11th vertebra was performed by IH (Infinite Horizon) impactor, which applied a pressure of 50 kdyn. The damaged spinal cords were re-exposed during the observation period under anesthesia, and then observed by two-photon excited fluorescence microscopy, which can observe deep regions of tissues including spinal cord axons. No significant morphological change of injured axons was observed immediately after injury. Three days after injury, the number of axons decreased, and residual axons were fragmented. Seven days after injury, only fragments were present in the damaged tissue. No hind-limb movement was observed during the observation period after injury. Despite the immediate paresis of hind-limbs following the contusion injury, the morphological degeneration of injured axons was delayed. This method may help clarification of pathophysiology of axon degeneration and development of therapeutic modules for the treatment of spinal cord injury.

[Analysis of Musculoskeletal Systems and Their Diseases. Musculoskeletal disease research by using imaging technique].

Intravital fluorescence imaging technique is a method that enables to visualize behavior and function of molecules and cells in vivo . Recently, the intravital fluorescence imaging technique has developed rapidly. In particular, development of functional fluorescent proteins and fluorescent dyes in conjunction with appropriate equipment including two-photon fluorescence microscope and image processing software enables to investigate bone and cartilage tissues in vivo . Here we show recent technological development of the intravital fluorescence imaging in biology. Moreover, we would discuss about issues of the intravital fluorescence imaging and the application of the fluorescent imaging approaches to bone and cartilage biology.

In vivo subcellular imaging of tumors in mouse models using a fluorophore-conjugated anti-carcinoembryonic antigen antibody in two-photon excitation microscopy.

Recently, there has been growing interest in applying fluorescence imaging techniques to the study of various disease processes and complex biological phenomena in vivo. To apply these methods to clinical settings, several groups have developed protocols for fluorescence imaging using antibodies against tumor markers conjugated to fluorescent substances. Although these probes have been useful in macroscopic imaging, the specificity and sensitivity of these methods must be improved to enable them to detect micro-lesions in the early phases of cancer, resulting in better treatment outcomes. To establish a sensitive and highly specific imaging method, we used a fluorophore-conjugated anti-carcinoembryonic antigen (CEA) antibody to perform macroscopic and microscopic in vivo imaging of inoculated cancer cells expressing GFP with or without CEA. Macroscopic imaging by fluorescence zoom microscopy revealed that bio-conjugation of Alexa Fluor 594 to the anti-CEA antibody allowed visualization of tumor mass consisting of CEA-expressing human cancer cells, but the background levels were unacceptably high. In contrast, microscopic imaging using a two-photon excitation microscope and the same fluorescent antibody resulted in subcellular-resolution imaging that was more specific and sensitive than conventional imaging using a fluorescence zoom microscope. These results suggest that two-photon excitation microscopy in conjunction with fluorophore-conjugated antibodies could be widely adapted to detection of cancer-specific cell-surface molecules, both in cancer research and in clinical applications.

Intravital multiphoton fluorescence imaging and optical manipulation of spinal cord in mice, using a compact fiber laser system.

BACKGROUND AND OBJECTIVE: Near-infrared ultrafast lasers are widely used for multiphoton excited fluorescence microscopy in living animals. Ti:Sapphire lasers are typically used for multiphoton excitation, but their emission wavelength is restricted below 1,000 nm. The aim of this study is to evaluate the performance of a compact Ytterbium-(Yb-) fiber laser at 1,045 nm for multiphoton excited fluorescence microscopy in spinal cord injury. MATERIALS AND METHODS: In this study, we employed a custom-designed microscopy system with a compact Yb-fiber laser and evaluated the performance of this system in in vivo imaging of brain cortex and spinal cord in YFP-H transgenic mice. RESULTS: For in vivo imaging of brain cortex, sharp images of basal dendrites, and pyramidal cells expressing EYFP were successfully captured using the Yb-fiber laser in our microscopy system. We also performed in vivo imaging of axon fibers of spinal cord in the transgenic mice. The obtained images were almost as sharp as those obtained using a conventional ultrafast laser system. In addition, laser ablation and multi-color imaging could be performed simultaneously using the Yb-fiber laser. CONCLUSION: The high-peak pulse Yb-fiber laser is potentially useful for multimodal bioimaging methods based on a multiphoton excited fluorescence microscopy system that incorporates laser ablation techniques. Our results suggest that microscopy systems of this type could be utilized in studies of neuroscience and clinical use in diagnostics and therapeutic tool for spinal cord injury in the future.

Ultrasensitive imaging of Ca2+ dynamics in pancreatic acinar cells of yellow cameleon-nano transgenic mice.

Yellow Cameleons are genetically encoded Ca2+ indicators in which cyan and yellow fluorescent proteins and calmodulin work together as a fluorescence (Förster) resonance energy transfer Ca2+-sensor probe. To achieve ultrasensitive Ca2+ imaging for low resting Ca2+ or small Ca2+ transients in various organs, we generated a transgenic mouse line expressing the highest-sensitive genetically encoded Ca2+ indicator (Yellow Cameleon-Nano 15) in the whole body. We then focused on the mechanism of exocytotic events mediated by intracellular Ca2+ signaling in acinar cells of the mice with an agonist and observed them by two-photon excitation microscopy. In the results, two-photon excitation imaging of Yellow Cameleon-Nano 15 successfully visualized intracellular Ca2+ concentration under stimulation with the agonist at nanomolar levels. This is the first demonstration for application of genetically encoded Ca2+ indicators to pancreatic acinar cells. We also simultaneously observed exocytotic events and an intracellular Ca2+ concentration under in vivo condition. Yellow Cameleon-Nano 15 mice are healthy and no significant deteriorative effect was observed on physiological response regarding the pancreatic acinar cells. The dynamic range of 165% was calculated from Rmax and Rmin values under in vivo condition. The mice will be useful for ultrasensitive Ca2+ imaging in vivo.

Development and preclinical evaluation of a new viewing filter system to control reflection and enhance dye staining during vitrectomy.

PURPOSE: We developed a new artificial image enhancement system and evaluated its usefulness in controlling intraoperative reflection and enhancing of Brilliant Blue G (BBG) staining. METHODS: The system was composed of three kinds of filters (a polarizing filter, a blue-enhancing filter, and a sharp-cut filter Y) and attached to the inferior surface of the operating microscope. Twenty-seven post-mortem extracted porcine eyes were used for a series of examinations. We performed surgery using the 23G-vitrectomy system with a halogen light and xenon lights and compared the reduction of intraoperative reflection under air condition and visibility and BBG contrast with and without this system. The evaluation of images was calculated in CIE 1976 (L*, a*, b*) color space (CIELAB) carried out by ImageJ software. The transmission of each filter and absorbance of BBG was measured by a spectrophotometer. We measured spectral irradiance at each wavelength about each filter from each light source with a spectroradiometer. RESULTS: Under both light sources, intraoperative reflection was controlled using a polarizing (PL) filter or combination of filters under air condition. Evaluation of the value of L* within the cutter surface was changed by 37.8 % under the halogen light, and 61.6 % (averaged) under the xenon light with inserted filters versus no filter. The BBG intensity difference was obtained with sharp-cut Y filter under both light source and PL with blue enhancing filter under the halogen light using each L*, a*, b* parameter with statistically significant (p < 0.01, 0.05). However, there was a relative decrease in the observation illuminance when the filter inserted according to the attenuation total spectral irradiance. CONCLUSIONS: This system can reduce intraoperative reflections under the air condition and obtain an excellent BBG staining intensity induced by various light sources.

Clinical evaluation and feasibility of changing intraoperative visibility with a novel viewing filter system for human eye.

PURPOSE: The study was conducted to develop a new viewing system as a clinical prototype that enables visibility during surgery. METHODS: The system was composed of several filters attached to the microscope. This nonrandomized, retrospective, observational case series study involved 33 eyes from 32 patients who presented with various diseases and underwent surgery. The authors evaluated the changes in visualization focusing on controlling intraoperative visibility under air infusion and enhancing Brilliant Blue G staining focusing a sharp-cut filter Y (SCY). Visibility was compared under various surgical conditions, including cataract surgery, both with and without this system. Quantitative analysis of changes in intraoperative reflection including halation under air infusion and Brilliant Blue G intensity was carried out using the International Commission on Illumination 1976 (L*, a*, b*) color space method. RESULTS: A SCY reduced the reflection and halation by a maximum of 69.6%, when compared with use of no filter under air infusion (P < 0.01). The color difference between Brilliant Blue G-stained and nonstained areas was improved by 127.8% relative to values with no filter and using SCY (P < 0.01) in macular hole cases. Furthermore, in cataract surgery with corneal opacity, improvement of visibility was observed by SCY insertion. CONCLUSION: The system improved intraoperative visibility under air infusion and the Brilliant Blue G staining intensity by use of SCY during vitrectomy.