Disruption of cholesterol homeostasis triggers periodontal inflammation and alveolar bone loss.

Oral diseases exhibit a significant association with metabolic syndrome, including dyslipidemia. However, direct evidence supporting this relationship is lacking, and the involvement of cholesterol metabolism in the pathogenesis of periodontitis (PD) has yet to be determined. In this study, we showed that high cholesterol caused periodontal inflammation in mice. Cholesterol homeostasis in human gingival fibroblasts was disrupted by enhanced uptake through C-X-C motif chemokine ligand 16 (CXCL16), upregulation of cholesterol hydroxylase (CH25H), and the production of 25-hydroxycholesterol (an oxysterol metabolite of CH25H). Retinoid-related orphan receptor α (RORα) mediated the transcriptional upregulation of inflammatory mediators; consequently, PD pathogenesis mechanisms, including alveolar bone loss, were stimulated. Our collective data provided direct evidence that hyperlipidemia is a risk factor for PD and supported that inhibition of the CXCL16-CH25H-RORα axis is a potential treatment mechanism for PD as a systemic disorder manifestation.

Unlocking the Potential of A-Site Ca-Doped LaCo0.2Fe0.8O3-δ: A Redox-Stable Cathode Material Enabling High Current Density in Direct CO2 Electrolysis.

Massive carbon dioxide (CO2) emission from recent human industrialization has affected the global ecosystem and raised great concern for environmental sustainability. The solid oxide electrolysis cell (SOEC) is a promising energy conversion device capable of efficiently converting CO2 into valuable chemicals using renewable energy sources. However, Sr-containing cathode materials face the challenge of Sr carbonation during CO2 electrolysis, which greatly affects the energy conversion efficiency and long-term stability. Thus, A-site Ca-doped La1-xCaxCo0.2Fe0.8O3-δ (0.2 ≤ x ≤ 0.6) oxides are developed for direct CO2 conversion to carbon monoxide (CO) in an intermediate-temperature SOEC (IT-SOEC). With a polarization resistance as low as 0.18 Ω cm2 in pure CO2 atmosphere, a remarkable current density of 2.24 A cm-2 was achieved at 1.5 V with La0.6Ca0.4Co0.2Fe0.8O3-δ (LCCF64) as the cathode in La0.8Sr0.2Ga0.83Mg0.17O3-δ (LSGM) electrolyte (300 µm) supported electrolysis cells using La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) as the air electrode at 800 °C. Furthermore, symmetrical cells with LCCF64 as the electrodes also show promising electrolysis performance of 1.78 A cm-2 at 1.5 V at 800 °C. In addition, stable cell performance has been achieved on direct CO2 electrolysis at an applied constant current of 0.5 A cm-2 at 800 °C. The easily removable carbonate intermediate produced during direct CO2 electrolysis makes LCCF64 a promising regenerable cathode. The outstanding electrocatalytic performance of the LCCF64 cathode is ascribed to the highly active and stable metal/perovskite interfaces that resulted from the in situ exsolved Co/CoFe nanoparticles and the additional oxygen vacancies originated from the Ca2Fe2O5 phase synergistically providing active sites for CO2 adsorption and electrolysis. This study offers a novel approach to design catalysts with high performance for direct CO2 electrolysis.

A study on the functional near-infrared spectroscopy on impaired prefrontal activation and impulsivity during cognitive task in patients with major depressive disorder.

BACKGROUND: This study aimed to examine the association between prefrontal activation during a verbal fluency task (VFT) and impulsivity among patients with major depressive disorder (MDD), using functional near-infrared spectroscopy (fNIRS). METHODS: We enrolled a total of 119 participants, 60 with MDD patients and 59 with healthy controls (HCs), aged 18 to 34 years. The Barratt Impulsiveness Scale-11 (BIS-11) was used to assess impulsivity after completing baseline demographic, clinical, and physical assessments. A VFT was used to examine prefrontal activation during cognitive executions while fNIRS was monitored. The changing values of oxygenated hemoglobin (oxy-Hb) and their associations with the BIS-11 score were analyzed. RESULTS: The data analysis comprised 109 participants in total (54 MDD; 55 HCs). Spearman's correlation analysis of the MDD group showed a negative correlation between changes in oxy-Hb and BIS-11 values in the right prefrontal cortex, notably the right frontopolar cortex (FPC) and ventromedial prefrontal cortex (VMPFC). After adjusting for sex, age, years of education, and Hamilton Depression Rating Scale (HAMD), significance was maintained in the right FPC [ρ = -0.317, p = 0.027], and the right VMPFC [ρ = -0.327, p = 0.022]. Furthermore, multivariate linear regression suggested a significant association in the right prefrontal cortex with BIS-11 score [ß = -1.904, SE = 0.799, p = 0.0214]. CONCLUSIONS: Impaired prefrontal activation during a verbal fluency task, led to higher impulsivity in patients with MDD.

N-methylformamide induces multiple organ toxicity in Fischer 344 rats.

N-Methylformamide (NMF) is a widely used chemical (CAS No.: 123-39-7) in several industries and its usage is continuously increasing. However, studies for NMF have been focused on hepatotoxicity from now. Its toxicity profile has not yet been established owing to limited toxicity data. Therefore, we evaluated systemic toxicity via NMF inhalation. We exposed 0, 30, 100, and 300 ppm NMF to Fischer 344 rats for 6 h/day, 5 days a week for 2 weeks. Clinical signs, body weights, food consumption, hematologic parameters, serum chemistry measurements, organ weights, necropsy, and histopathology were performed. Two females exposed to 300 ppm NMF died during exposure period. Decrease of food consumption and body weight in both sexes exposed to 300 ppm in females exposed to 100 ppm were noted during exposure period. Increased RBC and HGB were noted in females exposed to 300 ppm. A decrease in the levels of ALP and K and increase in the levels of TCHO and Na were observed in both sexes exposed to 300 and 100 ppm. Increased levels of ALT, AST, BUN and decreased levels of TP, ALB, Ca were observed in females exposed to 300 and 100 ppm. The relative liver weight was elevated in both sexes exposed to 300 and 100 ppm NMF. Hypertrophy in the liver and submandibular glands and nasal cavity injuries were noted in both sexes exposed to 300 and 100 ppm NMF. Tubular basophilia of the kidneys were noted in females exposed to 300 ppm NMF. We revealed that NMF affect several organs including the kidneys not only the liver and NMF-related toxicity is predominant in female rats. These results could contribute to the development of NMF toxicity profile and may help in developing strategies for the control of occupational environmental hazards related to NMF.

Generation of Parkinson's disease patient-derived human induced pluripotent stem cells line (PNUSCRi001-A) carrying a N227S mutation in GBA gene.

The hiPSC line was generated from peripheral blood mononuclear cells (PBMCs) collected by a male patient with young onset Parkinson's disease, carrying on heterozygous c.680 A > G (N227S) mutation in the GBA gene. The PBMCs was reprogrammed into an induced pluripotent stem cell (iPSC) line (PNUSCRi001-A hiPSCs) using non-integrative sendai virus. The hiPSC line, PNUSCRi001-A displayed a normal karyotype and the Expression of pluripotency markers that is capable of producing derivatives of three germ layers (Ectoderm, Endoderm and Mesoderm).

Human induced pluripotent stem cells line (PNUSCRi002-A) from a patient with Parkinson's disease carrying a R159W mutation in the GBA gene.

Mutation in the glucocerebrosidase encoding gene 1 (GBA) is one of the most frequent causes of Parkinson's disease (PD). Herein, we obtained peripheral blood mononuclear cells (PBMCs) from a patient with PD with a heterozygous c.475C > T (p.R159W) mutation in the GBA gene, and generated an induced pluripotent stem cell (iPSC) line (GBA PD9 or PNUSCRi002-A hiPSCs) using a non-integrative Sendai virus. The iPSC line expressed pluripotency markers (OCT4, NANOG, SSEA-4, TRA-1-60) and displayed differentiation properties in the three germ layers (ectoderm, endoderm, and mesoderm). Additionally, the patient had a normal karyotype.

A Novel Method for Calibration of Digital Soil Images Captured under Irregular Lighting Conditions.

Soil color is commonly used as an indicator to classify soil and identify its properties. However, color-based soil assessments are susceptible to variations in light conditions and the subjectivity of visual evaluations. This study proposes a novel method of calibrating digital images of soil, regardless of lighting conditions, to ensure accurate identification. Two different color space models, RGB and CIELAB, were assessed in terms of their potential utility in calibrating changes to soil color in digital images. The latter system was determined to be suitable, as a result of its ability to accurately reflect illuminance and color temperature. Linear regression equations relating soil color and light conditions were developed based on digital images of four different types of soil samples, each photographed under 15 different light conditions. The proposed method can be applied to calibrate variations in the soil color obtained by digital images, thus allowing for more standardized, objective, and accurate classification and evaluation of soil based on its color.

Thirteen-week inhalation toxicity study of 1-propanol in F344 rats.

1-Propanol is a colorless volatile liquid at room temperature and is an important industrial alcohol. Workers are potentially exposed to it through inhalation during industrial activities, including manufacturing, sampling, filling, and mixing processes, as well as during cleaning, maintenance, and repair. Consequently, further information and/or testing for inhalation-related toxicological data is required to assess occupational risk. In this study, 80 (40 male and 40 female) F344 rats were exposed to 1-propanol vapors for 13 weeks (6 h a day, 5 days per week) at target concentrations of 0, 500, 1,600, and 5200 ppm in a whole-body inhalation chamber system. Clinical signs, mean body weight changes, food consumption, hematology, blood biochemistry, necropsy, organ weight, and histopathological findings were observed. The exposure concentrations in chambers were 501.30 ± 9.54 ppm, 1605.43 ± 66.55 ppm, and 5202.19 ± 102.74 ppm for the low, middle, and high dose groups, respectively. No changes related to 1-propanol were observed, including histopathological findings, except for mean body weight changes. The significant decrease in mean body weight at a high dose was not considered to be an adverse effect. Based on these results, the no observed adverse effect concentration of 1-propanol was estimated to be 5202.19 ppm.

Hypoxia-inducible factor-2α mediates senescence-associated intrinsic mechanisms of age-related bone loss.

Aging is associated with cellular senescence followed by bone loss leading to bone fragility in humans. However, the regulators associated with cellular senescence in aged bones need to be identified. Hypoxia-inducible factor (HIF)-2α regulates bone remodeling via the differentiation of osteoblasts and osteoclasts. Here, we report that HIF-2α expression was highly upregulated in aged bones. HIF-2α depletion in male mice reversed age-induced bone loss, as evidenced by an increase in the number of osteoblasts and a decrease in the number of osteoclasts. In an in vitro model of doxorubicin-mediated senescence, the expression of Hif-2α and p21, a senescence marker gene, was enhanced, and osteoblastic differentiation of primary mouse calvarial preosteoblast cells was inhibited. Inhibition of senescence-induced upregulation of HIF-2α expression during matrix maturation, but not during the proliferation stage of osteoblast differentiation, reversed the age-related decrease in Runx2 and Ocn expression. However, HIF-2α knockdown did not affect p21 expression or senescence progression, indicating that HIF-2α expression upregulation in senescent osteoblasts may be a result of aging rather than a cause of cellular senescence. Osteoclasts are known to induce a senescent phenotype during in vitro osteoclastogenesis. Consistent with increased HIF-2α expression, the expression of p16 and p21 was upregulated during osteoclastogenesis of bone marrow macrophages. ChIP following overexpression or knockdown of HIF-2α using adenovirus revealed that p16 and p21 are direct targets of HIF-2α in osteoclasts. Osteoblast-specific (Hif-2αfl/fl;Col1a1-Cre) or osteoclast-specific (Hif-2αfl/fl;Ctsk-Cre) conditional knockout of HIF-2α in male mice reversed age-related bone loss. Collectively, our results suggest that HIF-2α acts as a senescence-related intrinsic factor in age-related dysfunction of bone homeostasis.

Four-week inhalation toxicity study of 1-propanol in F344 rats.

1-Propanol is used as a solvent for waxes, vegetable oils, resins, cellulose esters, and ethers, and is not considered harmful to humans by food and non-occupational exposures. However, workers are potentially exposed to 1-propanol by inhalation when it is used in the workplace. Thus, inhalation toxicity data are needed to assess the hazard of 1-propanol for workers safety. Five male and five female F344 rats were exposed to 1-propanol vapor for 4-weeks (6 h/day, 5 days/week) at concentrations of 0, 100, 400, and 1600 ppm in a whole-body inhalation chamber system. The actual exposure concentrations were 100.11 ± 5.10, 403.19 ± 12.31, and 1598.08 ± 139.58 ppm for the low, middle, and high dose groups, respectively. No clinical signs, significant mean body weight changes, significant changes of hematology or blood biochemistry results, or histopathological abnormalities were seen related to exposure to the test substance. Under the conditions of this study, the no-observed-adverse-effect level of 1-propanol was over 1600 ppm.

Evaluation of 1-Propanol Toxicity in B6C3F1 Mice via Repeated Inhalation over 28 and 90 Days.

We evaluated the toxicity of 1-propanol exposure following repeated inhalation over 28- and 90-day periods in male and female B6C3F1 mice to confirm the potential target organs and to determine the no-observable-adverse-effect levels (NOAELs). Five mice of each sex were exposed to 1-propanol at concentrations of 0, 100, 400, or 1600 ppm for 28 days and showed no consequent toxicity. Following this, ten mice of each sex were exposed at concentrations of 0, 500, 1600, or 5200 ppm for 90 days. We observed no effects on food consumption, body weight, organ weight, clinical signs, hematology and biochemistry parameters, or gross or histological features even at the maximum concentration. Therefore, the NOAEL of inhaled 1-propanol was defined as 5200 ppm (12.8 mg/L) for male and female mice under study conditions.

Antioxidant and Anti-Obesity Activities of Polygonum cuspidatum Extract through Alleviation of Lipid Accumulation on 3T3-L1 Adipocytes.

Natural products are widely used due to their various biological activities which include antiinflammatory, antioxidant, and anti-obesity effects. In this study, we determined the antioxidative and anti-obesity effects of Polygonum cuspidatum 50% ethanol extract (PEE). The antioxidative effect of PEE was evaluated using its radical scavenging activity, total phenolic content, and reducing power. The anti-obesity effect of PEE was investigated using 3T3-L1 adipocytes. The antioxidative activity of PEE was progressively increased in various concentrations, mainly due to the presence of phenolic compounds. PEE also alleviated lipid accumulation on 3T3-L1 adipocytes and downregulated the mRNA and protein production of adipogenesis-related (SREBP-1c, PPARγ, C/EBPα) and lipogenesis-related (aP2, FAS, ACC) markers. Furthermore, we found that the inhibitory effect on lipid accumulation via PEE was caused by the alleviation of NF-κB, p38 MAPK, ERK1/2, and JNK at the protein level. Taken together, our results imply that PEE is a potential antioxidant that can prevent obesityassociated disorders.

Quality of life in patients with oral leukoplakia.

BACKGROUND: Oral leukoplakia (OL) is the most common oral potentially malignant disorder, yet despite its chronic and potentially disabling nature, the literature concerning impacts of OL on quality of life (QoL) is limited. This study aimed to evaluate QoL in subjects with OL compared to controls using QoL questionnaires. METHODS: Fifty individuals with OL and 50 controls matched for age, gender, smoking, and alcohol use were administered the Short Generic Health Questionnaire (SF-12) and the discipline-specific Oral Potentially Malignant Disorder Questionnaire (OPMDQ). Responses were compared between the two groups. RESULTS: Subjects with OL reported poorer QoL scores compared to controls in two domains "Role limitations due to physical problems" and "Pain" of the SF-12 questionnaire, and in two domains "Difficulty with diagnosis" and "Effect of treatment on daily life" and in the overall scores of the OPMDQ. Females reported poorer QoL in the overall OPMD QoL score and in the domains of "Physical and function limitation" and "Psychological and social well-being," while older individuals in the domains of "Physical and function limitation" and "Effect of treatment on daily life." Non-alcohol drinkers and subjects with dysplastic or non-homogeneous OLs also reported poorer QoL scores. CONCLUSIONS: Quality of life assessments provide useful insight into the impact of OL on an individual's life and opportunity to improve clinical care.

Controlling hypoxia-inducible factor-2α is critical for maintaining bone homeostasis in mice.

Pathological bone loss is caused by an imbalance between bone formation and resorption. The bone microenvironments are hypoxic, and hypoxia-inducible factor (HIF) is known to play notable roles in bone remodeling. However, the relevant functions of HIF-2α are not well understood. Here, we have shown that HIF-2α deficiency in mice enhances bone mass through its effects on the differentiation of osteoblasts and osteoclasts. In vitro analyses revealed that HIF-2α inhibits osteoblast differentiation by targeting Twist2 and stimulates RANKL-induced osteoclastogenesis via regulation of Traf6. In addition, HIF-2α appears to contribute to the crosstalk between osteoblasts and osteoclasts by directly targeting RANKL in osteoprogenitor cells. Experiments performed with osteoblast- and osteoclast-specific conditional knockout mice supported a role of HIF-2α in this crosstalk. HIF-2α deficiency alleviated ovariectomy-induced bone loss in mice, and specific inhibition of HIF-2α with ZINC04179524 significantly blocked RANKL-mediated osteoclastogenesis. Collectively, our results suggest that HIF-2α functions as a catabolic regulator in bone remodeling, which is critical for the maintenance of bone homeostasis.

Novel Hg2+-Selective Signaling Probe Based on Resorufin Thionocarbonate and its µPAD Application.

In this study, a novel resorufin thionocarbonate-based Hg2+-selective signaling probe (RT) for microfluidic paper-based analytical device (µPAD) applications is reported. The designed probe, RT, was readily synthesized by the one-step reaction of resorufin with phenyl thionochloroformate. The RT probe displayed a prominent color change from yellow to pink and a marked turn-on fluorescence signaling behavior exclusively toward the Hg2+ ion. The signaling of RT was due to Hg2+-induced hydrolysis of the phenyl thionocarbonate moiety to form the parent resorufin dye, which restored its spectroscopic properties. In addition, RT exhibited the Hg2+-selective signaling behavior without interference by coexisting environmentally relevant metal ions. The detection limit for Hg2+ in simulated wastewater samples was estimated to be 5.8 × 10-8 M. In particular, an RT-equipped µPAD prepared using a wax printing technique enabled simple and convenient determination of Hg2+ ions in simulated wastewater samples, with a detection limit of 5.9 × 10-6 M.

Operation Protocols To Improve Durability of Protonic Ceramic Fuel Cells.

To develop reliable and durable protonic ceramic fuel cells (PCFCs), the impacts of the operation protocols of PCFCs on the cell durability are investigated through analyses of the main degradation mechanisms. We herein propose three appropriately designed control protocols, including cathode air depletion, shunt current, and fuel cell/electrolysis cycling, to fully circumvent the operating-induced degradation of PCFCs. For this purpose, anode-supported cells, comprised of a NiO-BaCe0.7Zr0.1Y0.1Yb0.1O3-δ anode, BaCe0.7Zr0.1Y0.1Yb0.1O3-δ electrolyte, and NdBa0.5Sr0.5Co1.5Fe0.5O5+δ-Nd0.1Ce0.9O2-δ composite cathode, are prepared, and their long-term performances are evaluated under a galvanostatic condition of 0.5 A·cm-2 at 650 °C. The cell voltages of the protected cells using the operation protocols to prevent performance degradation are stably maintained under the applied current density for more than 1200 h without any noticeable degradation, whereas the performance of the unprotected cell gradually decreased with time, and the decay ratio was 14.9% over 850 h. The significant performance decay of the unprotected cell is strongly associated with the cathode degradation phenomenon, which was caused by the water vapor continuously produced during the electrochemical reactions. Hence, the performance recovery of the PCFCs with the operation protocols is achieved by incrementally decreasing the cathode potential (close to a value of zero) to minimize the effect of high PH2O and PO2 during the PCFC operations.

The impact of visual symptoms on the quality of life of patients with early to moderate glaucoma.

PURPOSE: To investigate the visual symptoms and to determine the impact of visual symptoms on vision-related quality of life (QoL) in patients with early to moderate glaucoma. METHODS: A retrospective, hospital-based, cross-sectional study was conducted from July 1 to August 31, 2014, at a university referral center. A total of 176 patients with early to moderate glaucoma underwent a comprehensive ocular examination, including Humphrey visual field testing. The patients were divided into six groups based on visual symptoms that could be verified by forced-choice questions. Vision-related QoL was assessed by the Korean version of the National Eye Institute Visual Function Questionnaire 25 (K-NEI-VFQ-25). We compared the mean deviation (MD) and questionnaire scores among the groups. RESULTS: Of 352 eyes, 107 (30.4%) were symptomatic. The most common visual symptoms were partial blurring (15.91%), followed by a missing part (7.67%) and a black part (5.97%) of the image. The symptomatic groups (blurred part and missing part) had a significantly worse MD than the asymptomatic group. The symptomatic groups tended to have more visual field defects than the asymptomatic group. The overall NEI-VFQ-25 score in the symptomatic group (black part) was significantly lower than that in the asymptomatic group. Similar effects were observed for other subscale scores, including social functioning, mental health, role difficulties, dependency, and peripheral vision. CONCLUSIONS: Vision-related QoL may be severely compromised in glaucoma patients with visual symptoms. Patients with visual disorders should be evaluated for glaucoma and QoL.

Cationic Ti Complexes with Three [N,O]-Type Tetrazolyl Ligands: Ti↔Fe Transmetalation within Fe Metallascorpionate Complexes.

Herein, we report the synthesis of two novel ionic Ti complexes possessing three [N,O]-type bidentate ligands from the reaction of Fe metallascorpionate ligands possessing extended alcohol groups and TiCl4. The reaction of substituted hydroxyphenyl tetrazole and Fe(ClO4)3 in a molar ratio of 3:1 afforded iron scorpionate metalloligands possessing extended arms, which were characterized by IR spectroscopy and ESI-TOF-MS spectrometry. Their molecular structures were also confirmed as neutral Fe-centered scorpionate complexes by X-ray crystallography, in which the extended alcohol groups adopted a tripodal geometry. Moreover, two different crystals of iron scorpionate metalloligand grown from CH2Cl2 and CH3OH were studied, revealing that, in the latter crystal, the tripod arms are folded and aligned toward the C3-rotational axis of the molecule, whereas the tripod arms are unfolded and spread outward from the rotational axis in the former crystal. These metalloligands are solvatochromatic; a bathochromic shift was observed as the solvent polarity increased. From the reaction, the aforesaid Fe complexes were further reacted with TiCl4 in a molar ratio of 1:1 to produce ionic [TiL3]+[FeCl4]- (L = substituted hydroxyphenyl tetrazole) complexes from the transmetalation of Ti and Fe. The complexes were characterized by various analytical methods including UV/vis and IR spectroscopies, electrospray time-of-flight mass spectrometry (ESI-TOF-MS), and X-ray crystallography.

NAMPT enzyme activity regulates catabolic gene expression in gingival fibroblasts during periodontitis.

Periodontal disease is one of the most prevalent chronic disorders worldwide. It is accompanied by inflammation of the gingiva and destruction of periodontal tissues, leading to alveolar bone loss. Here, we focused on the role of adipokines, which are locally expressed by periodontal tissues, in the regulation of catabolic gene expression leading to periodontal inflammation. The expression of the nicotinamide phosphoribosyltransferase (NAMPT) adipokine was dramatically increased in inflamed human and mouse gingival tissues. NAMPT expression was also increased in lipopolysaccharide- and proinflammatory cytokine-stimulated primary cultured human gingival fibroblasts (GF). Adenovirus-mediated NAMPT (Ad-Nampt) overexpression upregulated the expression and activity of COX-2, MMP1 and MMP3 in human GF. The upregulation of IL-1ß- or Ad-Nampt-induced catabolic factors was significantly abrogated by the intracellular NAMPT (iNAMPT) inhibitor, FK866 or by the sirtuin (SIRT) inhibitor, nicotinamide (NIC). Recombinant NAMPT protein or extracellular NAMPT (eNAMPT) inhibition using a blocking antibody did not alter NAMPT target gene expression levels. Moreover, intragingival Ad-Nampt injection mediated periodontitis-like phenotypes including alveolar bone loss in mice. SIRT2, a part of the SIRT family, was positively associated with NAMPT actions in human GF. Furthermore, in vivo inhibition of the NAMPT-NAD+-SIRT axis by NIC injection in mice ameliorated the periodontal inflammation and alveolar bone erosion caused by intragingival injection of Ad-Nampt. Our findings indicate that NAMPT is highly upregulated in human GF, while its enzymatic activity acts as a crucial mediator of periodontal inflammation and alveolar bone destruction via regulation of COX-2, MMP1, and MMP3 levels.

Postoperative change in lateral rectus muscle insertion measured by anterior segment optical coherence tomography.

AimsThe aims of this study were to investigate the longitudinal change in lateral rectus (LR) muscle insertion after recession surgery, and to evaluate a relationship between insertion distance and postoperative amount of deviation.MethodsWe recruited 31 patients who underwent primary LR recession surgery with normal anterior segment structures. An AS-OCT scan of the LR muscle was performed at every visit. Data on sex, age, degree of deviation (prism diopter), and spur-LR insertion distance using AS-OCT were collected at preoperatively and postoperative months 1, 3, and 6. Spur-LR insertion was defined as the shortest distance between the insertion of the LR muscle and the scleral spur was measured using the caliper function in the AS-OCT software.ResultsThe mean distance of spur-LR insertion measured with AS-OCT was 5.5±0.7 mm preoperatively, and 11.1±0.9 mm at 1 month, 11.5±0.8 mm at 3 months, and 11.0±0.7 mm at 6 months postoperatively. There were significant differences in spur-LR insertion between postoperative 1 and 3 months, and between 3 and 6 months (generalized estimating equation, all P<0.001). The overall spur-LR insertion measurement has a significantly negative correlation with postoperative amount of deviation (Pearson's correlation, P=0.035, r=-0.218).ConclusionsAS-OCT is a useful instrument for understanding postoperative changes in EOM after tissue swelling subsides.