22 research outputs found

    Comparative effects of various types of toric intraocular lenses on astigmatism correction

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    Currently, various types of toric intraocular lenses (IOL) have been manufactured and can be divided into three types according to the location of correction component; front-toric IOL (correction on anterior IOL surface), back-toric IOL (correction on posterior IOL surface), and bi-toric IOL (correction on both anterior and posterior IOL surfaces). In this study, we aimed to investigate the effectiveness of reducing corneal astigmatism of either normal or post-penetrating keratoplasty (PKP) corneas according to the type of implanted toric IOLs. Medical records were retrospectively reviewed in 370 patients who had undergone phacoemulsification with posterior chamber toric IOL insertion (front-toric IOL, back-toric IOL or bi-toric IOL). Subjects were divided into 2 groups; subjects who had no history of corneal disease with corneal astigmatism more than 1.00 diopters (D) (G1) and subjects who received previous PKP with all corneal sutures removed and had corneal astigmatism more than 1.25D (G2). Preoperatively intended target from SRK/T was evaluated. Refractive astigmatism and its vector analysis (J0, J45), mean numerical error (MNE) and mean absolute error (MAE) were assessed at least a month after cataract surgery. Mean preoperative corneal astigmatisms were 2.2 D and 4.0 D in G1 and G2, respectively. There was significant reduction of mean postoperative refractive astigmatism to 0.89 D in G1 and to 2.33 D in G2. In G1, bi-toric IOL showed significantlymore improved refractive astigmatism than back-toric IOL. In G2, no difference in refractive astigmatism according to toric IOL type was observed. While G2 showed no difference in MNE among toric IOLs, in G1, bi-toric IOL showed significant hyperopic shift compared to back-toric IOL. In both groups, there was no significant difference in MAE according to type of IOL. No postoperative complications were observed. Our study suggests that all types of toric IOL are beneficial in correcting astigmatism of normal and post-PKP corneas. Noticeably, bi-toric IOL showed significantly better results in refractive astigmatism than back-toric IOL in normal cornea. However, bi-toric IOL showed a more hyperopic shift compared to back-toric IOL. Among post-PKP corneas, all types of toric IOL showed similar results

    Association between aging-dependent gut microbiome dysbiosis and dry eye severity in C57BL/6 male mouse model: a pilot study

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    Background While aging is a potent risk factor of dry eye disease, age-related gut dysbiosis is associated with inflammation and chronic geriatric diseases. Emerging evidence have demonstrated that gut dysbiosis contributes to the pathophysiology or exacerbation of ocular diseases including dry eye disease. However, the relationship between aging-related changes in gut microbiota and dry eye disease has not been elucidated. In this pilot study, we investigated the association between aging-dependent microbiome changes and dry eye severity in C57BL/6 male mice. Results Eight-week-old (8 W, n = 15), one-year-old (1Y, n = 10), and two-year-old (2Y, n = 8) C57BL/6 male mice were used. Dry eye severity was assessed by corneal staining scores and tear secretion. Bacterial genomic 16 s rRNA from feces was analyzed. Main outcomes were microbiome compositional differences among the groups and their correlation to dry eye severity. In aged mice (1Y and 2Y), corneal staining increased and tear secretion decreased with statistical significance. Gut microbiome α-diversity was not different among the groups. However, β-diversity was significantly different among the groups. In univariate analysis, phylum Firmicutes, Proteobacteria, and Cyanobacteria, Firmicutes/Bacteroidetes ratio, and genus Alistipes, Bacteroides, Prevotella, Paraprevotella, and Helicobacter were significantly related to dry eye severity. After adjustment of age, multivariate analysis revealed phylum Proteobacteria, Firmicutes/Bacteroidetes ratio, and genus Lactobacillus, Alistipes, Prevotella, Paraprevotella, and Helicobacter to be significantly associated with dry eye severity. Conclusions Our pilot study suggests that aging-dependent changes in microbiome composition are related to severity of dry eye signs in C57BL/6 male mice.This work was supported by the Cooperative Research Program of Basic Medical Science and Clinical Science from Seoul National University College of Medicine (grant no. 800–20190256) and by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1F1A1072506)

    Prognostic value of the ADAMTS13-vWF axis in disseminated intravascular coagulation: Platelet count/vWF:Ag ratio as a strong prognostic marker

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    © 2021 John Wiley & Sons Ltd.Introduction: ADAMTS13 deficiency increases the circulating level of von Willebrand factor (vWF). Low ADAMTS13 and high vWF can provide a milieu for microthrombosis, including disseminated intravascular coagulation (DIC). This study investigated the prognostic values of ADAMTS13–vWF axis markers and their correlation with DIC severity. Methods: ADAMTS13–vWF axis markers (vWF antigen (vWF:Ag), vWF ristocetin cofactor (vWF:Rco), ADAMTS13 activity, and anti-ADAMTS13 antibody) were measured in patients (n = 152) suspected of having DIC along with the well-known DIC markers including antithrombin and protein C. Result: The vWF:Ag level was significantly increased, and ADAMTS13 activity was significantly decreased in overt DIC. The vWF:Ag level (hazard ratio 7.365, p =.009), ADAMTS13 activity/vWF:Ag ratio (hazard ratio 3.777, p =.037), ADAMTS13 activity/vWF:Rco ratio (hazard ratio 3.027, p =.028), and platelet count/vWF:Ag ratio (hazard ratio 8.538, p <.001) were significant prognostic markers in Cox regression analysis and correlated well with DIC score and antithrombin and protein C levels. Conclusion: The platelet count/vWF:Ag was the strongest prognostic marker among ADAMTS13–vWF axis markers. The measurement of vWF:Ag may improve prognostic insights of DIC in clinical practice.N

    Matrix metalloproteinase 9 is associated with conjunctival microbiota culture positivity in Korean patients with chronic Stevens-Johnson syndrome

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    Background Stevens-Johnson syndrome (SJS) is an abnormal immune-response causing extensive exfoliation of the mucocutaneous tissue including conjunctiva. While several factors are associated with the alteration of conjunctival microbiota, the conjunctiva of SJS patients are found to harbor a different microbiota compared to healthy subjects. We investigated the conjunctival microbiota of Korean SJS patients, and identified factors associated with the conjunctival microbiota and its positive culture. Methods Medical records were retrospectively reviewed in 30 chronic SJS patients who had undergone conjunctival swab culture sampling. Demographic factors, chronic ocular surface complications score (COCS), tear break-up time (TBUT), tear secretion, tear matrix metalloproteinase 9 (MMP9), and results of conjunctival swab culture were assessed. Results Positive culture was seen in 58.1%. Gram positive bacteria was most commonly isolated, among which Coagulase-negative Staphylococci (45.5%) and Corynebacterium species (40.9%) were predominantly observed. Tear MMP9 positivity was observed significantly more in the positive culture group (100%) compared to the negative culture group (70%) (P = 0.041). Topical cyclosporine and corticosteroid were not associated with repetitive positive cultures. No significant differences in COCS, TBUT, and tear secretion were found between culture-positive and culture-negative groups. Conclusion Our study suggests that tear MMP9 positivity may be related with the presence of an abnormal ocular surface microbiota in chronic SJS patients.N

    Pixel-by-pixel Mean Opinion Score (pMOS) for No-Reference Image Quality Assessment

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    Deep-learning based techniques have contributed to the remarkable progress in the field of automatic image quality assessment (IQA). Existing IQA methods are designed to measure the quality of an image in terms of Mean Opinion Score (MOS) at the image-level (i.e. the whole image) or at the patch-level (dividing the image into multiple units and measuring quality of each patch). Some applications may require assessing the quality at the pixel-level (i.e. MOS value for each pixel), however, this is not possible in case of existing techniques as the spatial information is lost owing to their network structures. This paper proposes an IQA algorithm that can measure the MOS at the pixel-level, in addition to the image-level MOS. The proposed algorithm consists of three core parts, namely: i) Local IQA; ii) Region of Interest (ROI) prediction; iii) High-level feature embedding. The Local IQA part outputs the MOS at the pixel-level, or pixel-by-pixel MOS - we term it 'pMOS'. The ROI prediction part outputs weights that characterize the relative importance of region when calculating the image-level IQA. The high-level feature embedding part extracts high-level image features which are then embedded into the Local IQA part. In other words, the proposed algorithm yields three outputs: the pMOS which represents MOS for each pixel, the weights from the ROI indicating the relative importance of region, and finally the image-level MOS that is obtained by the weighted sum of pMOS and ROI values. The image-level MOS thus obtained by utilizing pMOS and ROI weights shows superior performance compared to the existing popular IQA techniques. In addition, visualization results indicate that predicted pMOS and ROI outputs are reasonably aligned with the general principles of the human visual system (HVS)

    The Incidence and Outcomes of Recurrence of Infection after Therapeutic Penetrating Keratoplasty for Medically-Uncontrolled Infectious Keratitis

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    Background: This study aimed to investigate the outcome of therapeutic penetrating keratoplasty (TPK) for medically-uncontrolled infectious keratitis, and to determine the factors associated with the recurrence of infection after TPK. Methods: A 10-year retrospective study of medically-uncontrolled infectious keratitis with positive culture results, who received TPK at a tertiary referral center in Korea was performed. Data collection included patient demographics, medical history, pre- and post-operative findings, surgical procedures, causative microorganisms, and visual acuities (VA). The primary outcome measure was the recurrence of infection after TPK, and the factors were compared between patients with and without recurrence. Results: A total of 19 patients (19 eyes) were analyzed, of which 6 eyes (31.6%) had infection recurrence at 21.6 +/- 22.84 months after TPK. Recurrence occurred more frequently in the female sex (vs. male, p = 0.013) and in longer duration (>30 days) from infection onset to TPK (vs. <= 30 days, p = 0.025). Final best-corrected-VA was poorer in patients with recurrence than those without (LogMAR 1.60 +/- 0.97 vs. 2.40 +/- 0.46, p = 0.026). Evisceration was performed in 2 out of 6 patients with recurrence (33.3%), while none was performed in those without recurrence (p = 0.028). Conclusion: Infection recurrence after TPK was 31.6%. Given the poor outcome of TPK in eyes with recurrence, close monitoring and intensive treatment are required post-TPK.Y

    Gut dysbiosis is prevailing in Sjögren's syndrome and is related to dry eye severity.

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    OBJECTIVE:To investigate gut dysbiosis in patients with Sjögren's syndrome (SS) or dry eye syndrome (DES) compared to normal subjects and to evaluate the association of dysbiosis with dry eye severity. METHODS:10 subjects with SS, 14 subjects with DES and 12 controls were enrolled. Corneal staining, tear break up time (TBUT) and tear secretion were evaluated. Bacterial genomic 16s rRNA from stool samples were analyzed. Main outcomes were microbiome compositional differences among groups and their correlation to dry eye signs. RESULTS:Gut microbiome analysis revealed significant compositional differences in SS compared to controls and DES. In phylum, Bacteriodetes increased, while Firmicutes/Bacteroidetes ratio and Actinobacteria decreased (p<0.05). In genus, Bifidobacterium was reduced (vs controls; p = 0.025, vs DES; p = 0.026). Beta diversity of SS also showed significant distances from controls and DES (p = 0.007 and 0.019, respectively). SS showed decreased genus of Blautia (p = 0.041), Dorea (p = 0.025) and Agathobacter (p = 0.035) compared to controls and increased genus of Prevotella (p = 0.026), Odoribacter (p = 0.028) and Alistipes (p = 0.46) compared to DES. On the other hand, DES only had increased genus Veillonella (p = 0.045) and reduced Subdoligranulum (p = 0.035) compared to controls. Bacteroidetes, Actinobacteria and Bifidobacterium were significantly related with dry eye signs (p<0.05). After adjustment of age, gender and group classification, multivariate linear regression analysis revealed tear secretion was strongly affected by Prevotella (p = 0.025). With additional adjustment of hydroxychloroquine use, TBUT was markedly affected by Prevotella (p = 0.037) and Actinobacteria (p = 0.001). CONCLUSIONS:Sjögren's syndrome showed significant gut dysbiosis compared to controls and environmental dry eye syndrome, while dry eye patients showed compositional changes of gut microbiome somewhere in between Sjögren's syndrome and controls. Dysbiosis of the gut microbiota was partly correlated to dry eye severity

    The Incidence and Outcomes of Recurrence of Infection after Therapeutic Penetrating Keratoplasty for Medically-Uncontrolled Infectious Keratitis

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    Background: This study aimed to investigate the outcome of therapeutic penetrating keratoplasty (TPK) for medically-uncontrolled infectious keratitis, and to determine the factors associated with the recurrence of infection after TPK. Methods: A 10-year retrospective study of medically-uncontrolled infectious keratitis with positive culture results, who received TPK at a tertiary referral center in Korea was performed. Data collection included patient demographics, medical history, pre- and post-operative findings, surgical procedures, causative microorganisms, and visual acuities (VA). The primary outcome measure was the recurrence of infection after TPK, and the factors were compared between patients with and without recurrence. Results: A total of 19 patients (19 eyes) were analyzed, of which 6 eyes (31.6%) had infection recurrence at 21.6 &plusmn; 22.84 months after TPK. Recurrence occurred more frequently in the female sex (vs. male, p = 0.013) and in longer duration (&gt;30 days) from infection onset to TPK (vs. &le;30 days, p = 0.025). Final best-corrected-VA was poorer in patients with recurrence than those without (LogMAR 1.60 &plusmn; 0.97 vs. 2.40 &plusmn; 0.46, p = 0.026). Evisceration was performed in 2 out of 6 patients with recurrence (33.3%), while none was performed in those without recurrence (p = 0.028). Conclusion: Infection recurrence after TPK was 31.6%. Given the poor outcome of TPK in eyes with recurrence, close monitoring and intensive treatment are required post-TPK

    Cancer cell-induced neutrophil extracellular traps promote both hypercoagulability and cancer progression.

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    IntroductionNeutrophils can generate extracellular net-like structures by releasing their DNA-histone complexes and antimicrobial peptides, which is called neutrophil extracellular traps (NETs). Various stimuli can induce NET formation. In particular, neutrophils and NET formation are abundant in tumor tissue. This study investigated how cancer cells induce NET formation and whether this NET formation promotes plasma thrombin generation and cancer progression.MethodsInduction of NET formation by a pancreatic cancer cell line (AsPC-1) was assessed by measuring the histone-DNA complex level. The endogenous thrombin potential (ETP) was measured by thrombin generation assay. In vitro migration, invasion, and tubule formation assays were performed. The circulating levels of NET markers and hypercoagulability markers were assessed in 62 patients with pancreatobiliary malignancy and 30 healthy controls.ResultsAsPC-1 significantly induced NET formation in a dose-dependent manner. Conditioned medium (CM) from AsPC-1 also induced NETs. Interestingly, NET-formation was abolished by heat-inactivated CM, but not by lipid-extracted CM, suggesting an important role of protein components. A reactive oxygen species inhibitor did not inhibit cancer cell-induced NET formation, but prostaglandin E1 (PGE1, cyclic adenosine monophosphate inducer) and antithrombin did. NETs significantly increased ETP of normal plasma. Of note, NETs promoted cancer cell migration and invasion as well as angiogenesis, which were inhibited by histone-binding agents (heparin, polysialic acid), a DNA-degrading enzyme, and Toll-like receptor neutralizing antibodies. In patients with pancreatobiliary malignancy, elevated NET markers correlated well with hypercoagulability makers.ConclusionOur findings indicate that cancer cell-induced NET formation enhances both hypercoagulability and cancer progression and suggest that inhibitors of NET formation such as PGE1 and antithrombin can be potential therapeutics to reduce both hypercoagulability and cancer progression
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