The cellular responses of corneal fibroblasts to cyclic stretching loads.

Mechanical signaling plays a crucial role in maintaining extracellular matrix (ECM) homeostasis in various structures. In this study, we investigated the responses of corneal fibroblasts to cyclic stretching loads using an in vitro cell culture system. Bovine corneal fibroblasts were cultured and subjected to equibiaxial cyclic strain of 15% for 72 h at a frequency of 0.25 Hz, with bovine skin fibroblasts used as a comparison. We explored various cellular behaviors, including morphological changes, cell proliferation, and metabolism in response to mechanical stretching loads. The expression of genes, protein secretion, and enzymatic activity for several major metalloproteinases was also determined through Q-PCR, Western blot, and gel zymography. Additionally, we investigated the involvement of mitogen-activated protein kinases (MAPKs) signaling pathways in the corneal fibroblasts when subjected to mechanical stimuli. Our findings revealed that, compared to skin fibroblasts, corneal fibroblasts were reluctant to morphological changes in response to a prolonged (72 h) and high-amplitude (15% of strain) cyclic stretching load. However, cyclic stretching loads stimulated the upregulation of MMP-2 expression in corneal fibroblasts via the MAPK signaling pathways involving extracellular signal-regulated kinase and p38. Together with a lack of upregulation in type I collagen expression, our results indicate the induction of the ECM degradation process in corneal fibroblasts in response to cyclic stretching. These findings emphasize the mechanoresponsive nature of corneal fibroblasts and shed light on the potential impact of intense mechanical stress on the cornea in both normal and pathological conditions such as keratoconus, providing valuable insights for understanding corneal mechanobiology.

Refractive outcomes of femtosecond laser-assisted cataract surgery with arcuate keratotomy and standard phacoemulsification with toric intraocular lens implantation.

PURPOSE: Femtosecond laser arcuate keratotomy (FS-AK) and toric intraocular lens (IOL) implantation are effective for the correction of eyes with corneal astigmatism. In this study, the postoperative refractive outcomes of patients receiving femtosecond laser-assisted cataract surgery (FLACS) with FS-AK and patients receiving standard phacoemulsification with toric IOL implantation were evaluated. METHODS: This retrospective study reviewed the postoperative outcomes of patients undergoing FLACS with FS-AK (the FS-AK group) and patients undergoing standard phacoemulsification with toric IOL implantation (the toric IOL group). The main outcome measures were uncorrected and corrected visual acuities, keratometric and refractive astigmatism, and vector analysis. RESULTS: The FS-AK group included 41 eyes with preoperative keratometric astigmatism of - 1.64 ± 0.42 diopters (D), and the toric IOL group included 53 eyes with preoperative keratometric astigmatism of - 2.29 ± 0.91 D (P < 0.001). Postoperative refractive astigmatism was comparable between the two groups. Compared with the FS-AK group, postoperative uncorrected visual acuity was significantly better (P = 0.005) and corrected visual acuity was marginally better in the toric IOL group (P = 0.051). The absolute angles of error were 9.95° ± 9.57° and 5.08° ± 4.94° (P = 0.02) in the FS-AK and the toric IOL groups, respectively. CONCLUSION: Both FLACS with FS-AK and standard phacoemulsification with toric IOL implantation are safe and effective methods for astigmatism correction during cataract surgery. Standard phacoemulsification with toric IOL implantation achieves better visual acuity than FLACS with FS-AK at the 6-month follow-up.

Clinico-microbiological profile of Burkholderia cepacia keratitis: a case series.

BACKGROUND: Burkholderia cepacia, an opportunistic pathogen mainly affecting patients with cystic fibrosis or immunocompromised, has rarely been documented as a cause of corneal infection. The clinical and microbiological profiles of B. cepacia keratitis are reported herein. METHODS: We retrospectively reviewed the medical record of 17 patients with culture-proven B. cepacia keratitis, treated between 2000 and 2019 at Chang Gung Memorial Hospital, Taiwan. Our data included predisposing factors, clinical presentations, treatments, and visual outcomes of B. cepacia keratitis as well as the drug susceptibility of the causative agent. RESULTS: The most common predisposing factor for B. cepacia keratitis was preexisting ocular disease (seven, 41.2%), particularly herpetic keratitis (five). Polymicrobial infection was detected in seven (41.2%) eyes. All B. cepacia isolates were susceptible to ceftazidime. Main medical treatments included levofloxacin or ceftazidime. Surgical treatment was required in five (29.4%) patients. Only four (23.5%) patients exhibited final visual acuity better than 20/200. CONCLUSIONS: B. cepacia keratitis primarily affects patients with preexisting ocular disease, particularly herpetic keratitis, and responds well to ceftazidime or fluoroquinolones. However, the visual outcomes are generally poor.

Paecilomyces/Purpureocillium keratitis: A consecutive study with a case series and literature review.

Paecilomyces/Purpureocillium species is an emerging pathogen of fungal keratitis; the risk factor, clinical course, and outcome of Paecilomyces/Purpureocillium keratitis need more exploration. We retrospectively reviewed 12 patients with culture-proven Paecilomyces/Purpureocillium keratitis in our hospital from 2003 to 2017 and combined them with 50 previous cases reported after the review conducted by Yuan et al. in 2009. Clinical features between the previously and newly reported cases were compared using the publication by Yuan et al. as a cutoff point. The mean age of the 62 newly reported patients with Paecilomyces/Purpureocillium keratitis was 52.7 years. Of these, contact lens wear was the most common predisposing factor (n = 32, 52%), followed by a preexisting corneal disease or previous ocular surgery (n = 12, 19%), and trauma (n = 8, 13%). Fifty eyes (81%) were treated with voriconazole, of which 31 (63%) were medically cured. Twenty-one of 62 eyes (34%) required therapeutic surgery. Compared with the 42 patients reported by Yuan et al., the patients were younger (P = .025); a higher proportion of the patients were contact lens wearers (P = .005); more patients were treated with voriconazole (P = .000); fewer patients required therapeutic surgery (P = .000) in recent reports. Contact lens use has become the major risk factor for Paecilomyces/Purpureocillium keratitis. The surgical rate has been significantly lower in recent publications, probably because of the prevalent use of voriconazole.

Clinical demographics of pterygium excision and prevalence of conjunctival intraepithelial neoplasia: a 15-year review.

PURPOSE: To find clinical demographics of pterygium surgery and prevalence of conjunctival intraepithelial neoplasia (CIN) in pterygium specimen. METHODS: This is a retrospective, institutional study. The records of patients who had received pterygium excision from 2000 to 2014 were reviewed. Patients after complete ophthalmic "examinations", surgical procedures, and pathological reports were enrolled. Surgical procedures, pathology, external eye photography, prevalence of CIN in specimen, and demographic data were described. RESULTS: Of 1787 pterygium cases, 928 were male and 859 were female. The mean age was 65.19 ± 14.21 years. Of these 1787 cases, 1435 (80.3%) cases had primary pterygium excision, while the others (n = 352; 19.7%) had pterygium excision for recurrence. Four cases presented CIN within pterygium tissue (0.22%). The mean age of pterygium patients with CIN was 57.75 ± 7.80 years. In stratified data, our patients who received primary and secondary pterygium excision were found prevalent in the eighth (28.2%) and seventh (26.1%) decade, respectively. Twelve percent of patients who underwent secondary pterygium excision had a recurrence and required another surgery. Patients requiring amniotic membrane transplantation (AMT) during primary pterygium excision were significantly younger (median, 58 years) than those (median, 67 years) without the assistance of AMT (p < 0.001). Similarly, AMT was utilized in younger patients (median, 56 years) during secondary pterygium excision, compared to those without AMT (median, 64 years) (p = 0.001). CONCLUSION: CIN combined with pterygium is very rare. However, the possibility of the development of ocular surface squamous neoplasia in pterygium tissue should not be ignored. Meticulous pathological investigation of the surgical samples is important.

Intravital multiphoton microscopic imaging platform for ocular surface imaging.

The purpose of this study is to provide an intravital noninvasive multiphoton microscopic platform for long-term ocular imaging in transgenic fluorescent mice with subcellular resolution. A multiphoton microscopic system with tunable laser output was employed. We designed a mouse holder incorporated with stereotaxic motorized stage for in vivo three-dimensional imaging of ocular surface in 3 transgenic mouse line with fluorescent protein (FP) expression to visualize distinct structures. With our imaging platform and the expression of FPs, we obtained the three-dimensional images across the whole cornea from epithelium to endothelium and in conjunctiva with subcellular resolution in vivo. Specified EGFP expression in corneal epithelium of K5-H2B-EGFP mice helped to identify both corneal and limbal epithelial cells while ubiquitous nuclear FP expression in R26R-GR mice allowed us to visualized nuclei of all cell types. Universal membrane-localized FP in mT/mG mice outlined all cell boundaries, nerve fibers, and capillaries. The simultaneously collected second harmonic generation signals from collagenous stroma provided architectural contrast. Time-lapsed recording enabled monitoring the mitotic activity of corneal epithelial cells and limbal epithelial cells. We developed an intravital multiphoton microscopic stereotaxic imaging platform and showed that, by incorporating FP-expressing transgenic mice, this platform enables in vivo 4-dimensional ophthalmic study at subcellular resolution.

Myopic Regression after FS-LASIK and SMILE.

PURPOSE: To compare the degree of myopic regression after myopia correction with either femtosecond laser-assisted in situ keratomileusis (FS-LASIK) or small-incision lenticule extraction (SMILE) over 18 months. METHODS: Patients undergoing FS-LASIK or SMILE surgery for myopia correction were retrospectively recruited. The propensity scores were used to match patients by age and preoperative manifest spherical equivalent (SEQ) from these 2 groups. Myopic regression was analyzed using the Cox proportional hazard model. RESULTS: A total of 416 eyes of 416 patients undergoing FS-LASIK and 416 eyes of 416 patients undergoing SMILE were matched. Using 1-month SEQ as baseline, the SEQ regression values after FS-LASIK were 0D, -0.17 ± 0.69D, -0.24 ± 0.65D, -0.31 ± 0.65D, -0.32 ± 0.63D, and -0.33 ± 0.62D and the SEQ regression values after SMILE were 0D, -0.07 ± 0.75D, -0.18 ± 0.77D, -0.23 ± 0.82 D, -0.21 ± 0.77D, and -0.24 ± 0.68D at 1, 3, 6, 9, 12, and 18 months, respectively. The Cox proportional hazard model showed that preoperative manifest SEQ (P = 0.021) and designed optical zone (P = 0.048) are significant predictors. The selected surgical procedure had no significant effect on predicting myopic regression (P = 0.470). The cumulative survival rates of myopic regression were 54.74% and 42.10% in the FS-LASIK group and 58.66% and 43.83% in the SMILE group, at 12 and 18 months, respectively (log-rank test, P = 0.11). CONCLUSIONS: After matching based on age and preoperative manifest SEQ, we found that higher myopia and a smaller optical zone contribute significantly to the development of myopic regression after undergoing FS-LASIK or SMILE surgery at 18 months. The selected surgical procedure, however, does not affect the likelihood of myopic regression.

Single-Cell Transcriptomics Reveals Cellular Heterogeneity and Complex Cell-Cell Communication Networks in the Mouse Cornea.

Purpose: To generate a single-cell RNA-sequencing (scRNA-seq) map and construct cell-cell communication networks of mouse corneas. Methods: C57BL/6 mouse corneas were dissociated to single cells and subjected to scRNA-seq. Cell populations were clustered and annotated for bioinformatic analysis using the R package "Seurat." Differential expression patterns were validated and spatially mapped with whole-mount immunofluorescence staining. Global intercellular signaling networks were constructed using CellChat. Results: Unbiased clustering of scRNA-seq transcriptomes of 14,732 cells from 40 corneas revealed 17 cell clusters of six major cell types: nine epithelial cell, three keratocyte, two corneal endothelial cell, and one each of immune cell, vascular endothelial cell, and fibroblast clusters. The nine epithelial cell subtypes included quiescent limbal stem cells, transit-amplifying cells, and differentiated cells from corneas and two minor conjunctival epithelial clusters. CellChat analysis provided an atlas of the complex intercellular signaling communications among all cell types. Conclusions: We constructed a complete single-cell transcriptomic map and the complex signaling cross-talk among all cell types of the cornea, which can be used as a foundation atlas for further research on the cornea. This study also deepens the understanding of the cellular heterogeneity and heterotypic cell-cell interaction within corneas.

Ocular Manifestations and Outcomes in Children With Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: A Comparison With Adult Patients.

PURPOSE: To compare the clinical features and visual outcomes in children and adults with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). DESIGN: Retrospective comparative case series. METHODS: This retrospective study included 280 eyes of 140 patients (35 children and 105 adults) with SJS/TEN treated between 2010 and 2020. The primary outcome measures were the final best-corrected visual acuity (BCVA) and severity of dry eye. The secondary outcome measure was the medical and surgical therapies used. RESULTS: Among 64 eyes of children recruited in the study, acute ocular involvement was found in 58 eyes (90.6%). The chronic score in pediatric patients was significantly higher than that in adult patients (P = .004). The use of antibiotics/nonsteroidal anti-inflammatory drugs (NSAIDs) and Mycoplasma infection were the more common etiologies in children. In all, 75% of eyes in children maintained a visual acuity of 20/40 or better at a mean follow-up time of 4.3 years. The severity of dryness was comparable between the child and adult groups. The proportion of eyes undergoing amniotic membrane and oral mucosa transplantation was significantly higher in children than in adults in the chronic stage, reflecting that children exhibit much more severe complications. CONCLUSIONS: Although pediatric SJS/TEN patients have more severe ocular complications than adults, most children maintain long-term good vision. Early intervention and aggressive treatment help to preserve vision.

Methicillin-resistant Staphylococcus aureus ocular infection: a 10-year hospital-based study.

PURPOSE: To characterize the patient demographics, clinical features, and antibiotic susceptibility of ocular infections caused by methicillin-resistant Staphylococcus aureus (MRSA), including community-associated (CA) and healthcare-associated (HA) isolates. DESIGN: Retrospective, observational study. PARTICIPANTS: Patients (n = 519) with culture-proven S. aureus ocular infections seen between January 1, 1999, and December 31, 2008, in Chang Gung Memorial Hospital. METHODS: Data collected included patient demographics and clinical information. Antibiotic susceptibility was verified by disc diffusion method. MAIN OUTCOME MEASURES: Proportion of MRSA in S. aureus ocular infections and the clinical characteristics, diagnoses, and antibiotic susceptibility patterns of CA-MRSA versus HA-MRSA ocular infections. RESULTS: We identified 274 patients with MRSA ocular infections, which comprised 181 CA-MRSA and 93 HA-MRSA isolates. The average rate of MRSA in S. aureus infections was 52.8% with a stable trend, whereas the annual ratio of CA-MRSA in ocular MRSA infections averaged 66.1% and tended to increase over the 10-year interval. Patients with ocular CA-MRSA were younger. Lid and lacrimal system disorders were more common, but keratitis, endophthalmitis, and wound infection were less common among CA-MRSA cases than HA-MRSA cases. Both CA-MRSA and HA-MRSA isolates were resistant to clindamycin and erythromycin, but CA-MRSA was more susceptible to sulfamethoxazole/trimethoprim. CONCLUSIONS: Community-associated MRSA is an important pathogen of ocular infections; CA-MRSA and HA-MRSA ocular infections differ demographically and clinically, but both strains were multi-resistant in Chang Gung Memorial Hospital, one of the biggest referral centers in Taiwan. In a country with a high prevalence of MRSA, ophthalmologists should be aware of such epidemiologic information.

Fusarium Keratitis in Taiwan: Molecular Identification, Antifungal Susceptibilities, and Clinical Features.

We performed molecular identification and antifungal susceptibilities of pathogens and investigated clinical features of 43 culture-proven Fusarium keratitis cases from 2015-2020 in Taiwan. The pathogens were identified by sequencing of their internal transcribed spacer regions of ribosomal DNA and translation elongation factor 1α gene; their antifungal susceptibilities (to seven agents) were determined by broth microdilution method. We also collected clinical data to compare the drug susceptibilities and clinical features of Fusarium solani species complex (FSSC) isolates with those of other Fusarium species complexes (non-FSSC). The FSSC accounted for 76.7% pathogens, among which F. falciforme (32.6%) and F. keratoplasticum (27.9%) were the most common species. Among clinically used antifungal agents, amphotericin B registered the lowest minimal inhibitory concentration (MIC), and the new azoles efinaconazole, lanoconazole and luliconazole, demonstrated even lower MICs against Fusarium species. The MICs of natamycin, voriconazole, chlorhexidine, lanoconazole, and luliconazole were higher for the FSSC than the non-FSSC, but no significant differences were noted in clinical outcomes, including corneal perforation and final visual acuity. In Taiwan, the FSSC was the most common complex in Fusarium keratitis; its MICs for five tested antifungal agents were higher than those of non-FSSC, but the clinical outcomes did not differ significantly.

Application of a Deep Learning System in Pterygium Grading and Further Prediction of Recurrence with Slit Lamp Photographs.

BACKGROUND: The aim of this study was to evaluate the efficacy of a deep learning system in pterygium grading and recurrence prediction. METHODS: This was a single center, retrospective study. Slit-lamp photographs, from patients with or without pterygium, were collected to develop an algorithm. Demographic data, including age, gender, laterality, grading, and pterygium area, recurrence, and surgical methods were recorded. Complex ocular surface diseases and pseudopterygium were excluded. Performance of the algorithm was evaluated by sensitivity, specificity, F1 score, accuracy, and area under the receiver operating characteristic curve. Confusion matrices and heatmaps were created to help explain the results. RESULTS: A total of 237 eyes were enrolled, of which 176 eyes had pterygium and 61 were non-pterygium eyes. The training set and testing set were comprised of 189 and 48 photographs, respectively. In pterygium grading, sensitivity, specificity, F1 score, and accuracy were 80% to 91.67%, 91.67% to 100%, 81.82% to 94.34%, and 86.67% to 91.67%, respectively. In the prediction model, our results showed sensitivity, specificity, positive predictive value, and negative predictive values were 66.67%, 81.82%, 33.33%, and 94.74%, respectively. CONCLUSIONS: Deep learning systems can be useful in pterygium grading based on slit lamp photographs. When clinical parameters involved in the prediction of pterygium recurrence were included, the algorithm showed higher specificity and negative predictive value in prediction.

Amniotic membrane transplantation in a patient with impending perforated corneal ulcer caused by Streptococcus mitis: A case report and review of literature.

BACKGROUND: Streptococcus mitis (S. mitis) is an opportunistic pathogen that can lead to severe ocular infections. In previous reports, penetrating keratoplasty (PK) was usually adopted for the treatment of persistent corneal ulcers. This report describes an unusual case of nonhealing descemetocele caused by S. mitis treated by antibiotics plus amniotic membrane transplantation (AMT). CASE SUMMARY: A 63-year-old woman presented with a right persistent corneal ulcer that she had suffered from for the past 9 mo. The culture of a corneal scraping yielded S. mitis. The right eye descemetocele decreased in diameter from 3 to 0.8 mm after the continuous administration of topical vancomycin and ceftriaxone for 2 wk. Due to the slow healing, AMT was performed. Her corneal erosion healed and gradually became clear. Her visual acuity recovered from initially counting fingers to 100/200 at the last follow-up, 67 mo after AMT. CONCLUSION: Antibiotics plus AMT may be an effective alternative treatment other than PK to promote epithelialization and to reduce inflammation in the corneas complicated by S. mitis keratitis.

Studies of intracorneal distribution and cytotoxicity of quantum dots: risk assessment of eye exposure.

The cornea is a potential route of exposure and drug administration for nanoparticles. In this work, we use noninvasive two-photon microscopic imaging to study the distribution and permeability pathway of CdSe/ZnS core/shell quantum dots (QDs) capped with three different functional groups through the cornea. With no additional staining, the two-photon image clearly discloses that fluorescent QDs penetrate and reside within the interlamellar space of second harmonic generating collagenous stroma when the corneal epithelium barrier is injured. An in vitro cytotoxicity test using bovine corneal stromal cells incubated individually with all three kinds of QDs indicates that the cell viability decreases significantly as the QD concentration and incubation period increased. The results also show that the specific QDs influence corneal stromal cell viability up to a significant magnitude of 50% under a relatively low concentration (5-20 nM) and short exposure period (24-48 h). Furthermore, two-photon imaging shows that QDs can be retained within the cornea up to 26 days in an in vivo mouse model. On the basis of our in vivo and in vitro data, we conclude that QDs can penetrate and be retained within cornea long enough to cause consequential cytotoxicity, under the circumstance in which the corneal epithelium barrier is injured. Since corneal abrasion is quite a common situation in daily life, our work raises public attention to the potential risk of eye exposure to nanoparticles.

Clinical characteristics and topographic findings of corneal ectasia in patients with symptomatic Demodex blepharitis.

PURPOSE: The purpose of this study is to present characteristics and topographic findings of patients with corneal ectasia and symptomatic ocular demodicosis. MATERIALS AND METHODS: A retrospective, noncomparative study. Twenty-one patients with symptomatic ocular demodicosis and corneal ectasia since 2017 to 2019 were enrolled. Patients with dry eye syndrome and meibomian gland dysfunction were identified and treated. Demographic data, topography, and clinical data were collected. All patients underwent lash sampling to confirm Demodex mite infestation by direct visualization under the microscope. RESULTS: Twenty-one ectasia patients (36 eyes) were enrolled with male preponderance (M:F =18:3). Mean age (years) was 28.6 ± 8.12. Of the 21 cases reviewed, the average number of topography taken was 6.8 within 43.8 months of follow-up. Corneal ectasia was characterized by focal thinning area beside central cornea, with corresponding mean thickness of 487.1 µm and 518 µm, respectively. All ectasia patients were combined with Demodex blepharitis and associated symptoms, proven by direct microscopic examination. After treatment with eyelid cleanser (OCuSOFT® Lid Scrub® PLUS), warm compress, and improved daily hygiene, ocular demodicosis and topographic changes were controlled and even reversed. CONCLUSION: Our results indicated that ocular demodicosis may be potentially associated with corneal ectasia. Demodex blepharitis still remains an overlooked differential diagnosis in clinic; however, it may be one of the risk factors triggering eye rubbing. Comorbidity of lid infestation with eye rubbing may lead to corneal ectasia, even in elder patients with thick cornea. Therefore, meticulous examination and intensive treatment were highly recommended in this group of patients.

Clinical Aspects of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis With Severe Ocular Complications in Taiwan.

Purpose: Over the last decade, there has been tremendous progress in the treatment of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). To understand whether this has resulted in better ophthalmic outcomes, we aimed to study the incidence of severe ocular complications (SOCs) in the acute and chronic stage among SJS/TEN patients, major causative medications, and therapeutic effect of medical and surgical treatment. Methods: Using electronic medical records review of patients of Chang Gung Memorial Hospital Linkou Branch from 2010 to 2020, 119 patients (236 eyes) received ophthalmic consultation during the acute stage and were retrospectively studied. Sotozono's grading score systems for acute and chronic SJS/TEN were employed for accessing correlation between acute and chronic presentations, the therapeutic effect of systemic etanercept treatment, and outcome of early amniotic membrane transplantation (AMT) performed in patients with severe acute SOCs. Results: There were 46 male and 73 female patients with a mean age of 45.6 ± 22.7 years old (2-90 years), and follow-up time of 408.3 ± 351.0 (116-1,336) days. The numbers of patients with SJS, overlap syndrome, and TEN were 87, 9, and 23, respectively. In total, 109 eyes (55 patients) had acute SOCs, which comprised 46.2% of patients who underwent ophthalmic examination. Antiepileptics were the most common category of culprit drugs causing SOCs in the acute stage. At the end of follow-up, there were 14 eyes (9 patients) with chronic SOCs (5.9%), and non-steroidal anti-inflammatory drugs and cold medicine were the most common causative medications that were associated with severe chronic sequela. The correlation between Sotozono's acute and chronic grading score showed a positive relationship [Spearman's rank correlation coefficient (r) = 0.52, p < 0.001]. The average chronic grading scores in patients receiving systemic corticosteroid combined with etanercept treatment were significantly lower than those receiving corticosteroid only, Finally, the average chronic grading scores in patients receiving AMT <7 days after onset were significantly lower than those performed beyond 7 days. Conclusion: Our study implies that acute manifestation can be an indicator for chronic sequelae. Additional early etanercept treatment and early AMT showed beneficial effect in reducing chronic ocular sequela.

Clinical Features and Molecular Characteristics of Methicillin-Susceptible Staphylococcus aureus Ocular Infection in Taiwan.

This study analyzed the clinical features and molecular characteristics of methicillin-susceptible Staphylococcus aureus (MSSA) ocular infections in Taiwan and compared them between community-associated (CA) and health-care-associated (HA) infections. We collected S. aureus ocular isolates from patients at Chang Gung Memorial Hospital between 2010 and 2017. The infections were classified as CA or HA using epidemiological criteria, and the isolates were molecularly characterized using pulsed-field gel electrophoresis, multilocus sequence typing, and Panton-Valentine leukocidin (PVL) gene detection. Antibiotic susceptibility was evaluated using disk diffusion and an E test. A total of 104 MSSA ocular isolates were identified; 46 (44.2%) were CA-MSSA and 58 (55.8%) were HA-MSSA. Compared with HA-MSSA strains, CA-MSSA strains caused a significantly higher rate of keratitis, but a lower rate of conjunctivitis. We identified 14 pulsotypes. ST 7/pulsotype BA was frequently identified in both CA-MSSA (28.3%) and HA-MSSA (37.9%) cases. PVL genes were identified in seven isolates (6.7%). Both CA-MSSA and HA-MSSA isolates were highly susceptible to vancomycin, teicoplanin, tigecycline, sulfamethoxazole-trimethoprim, and fluoroquinolones. The most common ocular manifestations were keratitis and conjunctivitis for CA-MSSA and HA-MSSA, respectively. The MSSA ocular isolates had diverse molecular characteristics; no specific genotype differentiated CA-MSSA from HA-MSSA. Both strains exhibited similar antibiotic susceptibility.

Ultrasensitive Detection of Alzheimer's Amyloids on a Plasmonic-Gold Platform.

More than 55 million people live with dementia worldwide in 2021, and there are nearly 10 million new cases every year. Alzheimer's disease (AD) is the most common cause of dementia. Despite urgent need, early detection of AD and long-term monitoring of AD progression have been challenging. This is due to the limited availability of brain imaging facilities and the highly invasive procedure with the cerebrospinal fluid assay to assess the level of AD biomarkers, such as beta-amyloid (Aß). Reliable measurements of AD biomarkers in blood samples are still difficult because of their very low abundance. Here, we develop a rapid, specific, and ultrasensitive immunoassay using plasmonic-gold nanoisland (pGOLD) chips with near-infrared fluorescence-enhanced detection for Aß1-40 and Aß1-42. We show step-by-step processes and results during the platform establishment, including antibody specificity and sensitivity tests, antibody pair examination, condition optimization, and procedure refinement. Finally, we demonstrate the platform performance with detection sensitivity at the subpicogram per milliliter level. This platform, therefore, has a great application potential for early detection of AD using blood samples.

Long-Term Intravital Imaging of the Cornea, Skin, and Hair Follicle by Multiphoton Microscope.

Multiphoton microscopy allows long-term direct visualization of cells in live animals due to its low photodamage. When coupled with fluorescence protein targeting and second harmonic generation signals from natural collagen as contrast, multiphoton microscopy enables intravital tracing of cells while providing structural information from the extracellular matrix. Compared with conventional histological analysis, it can bring new insight into the cell dynamics in stem cell research. Here, we demonstrate cell imaging and tracing at a single cell resolution in the cornea, skin, and hair follicles using multiphoton microscopy in transgenic mice of which specific cell populations are tagged with fluorescent proteins.