Hsin-Chiung Lin

Multiphoton fluorescence and second harmonic generation microscopy for imaging infectious keratitis.

The purpose of this study is to demonstrate the application of multiphoton fluorescence and second harmonic generation (SHG) microscopy for the ex-vivo visualization of human corneal morphological alterations due to infectious processes. The structural alterations of both cellular and collagenous components can be respectively demonstrated using fluorescence and SHG imaging. In addition, pathogens with fluorescence may be identified within turbid specimens. Our results show that multiphoton microscopy is effective for identifying structural alterations due to corneal infections without the need of histological processing. With additional developments, multiphoton microscopy has the potential to be developed into an imaging technique effective in the clinical diagnosis and monitoring of corneal infections.

Infectious keratitis related to overnight orthokeratology.

PURPOSE To report the microbial culture results, clinical course, and visual outcomes for infectious keratitis related to overnight orthokeratology. METHODS The records of patients with infectious keratitis related to overnight orthokeratology who presented to a tertiary referral center from April 2000 to March 2003 were retrospectively reviewed. RESULTS Twenty patients (21 eyes) were included; 1 patient had bilateral infections. The average age of the patients was 14 years. The average period between the time the patient started the overnight orthokeratology program and the onset of infectious keratitis was 23 months. Thirteen of the 21 eyes were culture positive. Organisms cultured were Pseudomonas aeruginosa (n = 9), coagulase-negative Staphylococcus species (n = 2), Serratia marcescens (n = 1), and Acathamoeba species (n = 1). All patients responded well to medical antimicrobial treatment. Final best spectacle-corrected visual acuity ranged from 20/20 to 20/100. CONCLUSIONS Infectious keratitis is a potential complication of overnight orthokeratology that may cause significant visual impairment. Parents of children who consider overnight orthokeratology should evaluate the benefit of temporary myopia reduction and the risk of infection.

Medical treatment for combined Fusarium and Acanthamoeba keratitis

Purpose:  Acanthamoeba and fungal keratitis are rare ocular infections. We report cases of combined Fusarium and Acanthamoeba keratitis and the clinical course of medical treatment.

Deletion of the FHL2 Gene Attenuating Neovascularization after Corneal Injury

PURPOSE The four-and-one-half LIM domain-containing protein2 (FHL2) is a member of the four-and-a-half LIM domain-only (FHL) gene family. Although FHL2 is expressed in the cornea, its role in angiogenesis is unclear. The aim of this study was to investigate the role of the FHL2 gene in corneal angiogenesis after chemical injury. METHODS FHL2-LacZ knock-in mice were used to trace FHL2 gene expression before and after corneal injury. Corneal angiogenesis between FHL2-null mice and wild-type mice that underwent chemical and mechanical denudation of corneal and limbal epithelium were compared. New growth vessel density was assessed by CD31 staining and was analyzed using image analysis software. Levels of vascular endothelial growth factor (VEGF) and cyclooxygenase (COX)-2 proteins were determined by Western blot assay. RESULTS beta-Galactosidase staining of corneal tissue in FHL2-LacZ knock-in mice revealed that FHL2 gene expression is upregulated in the corneal epithelium after corneal injury. Ten days after injury, corneal neovascularization was observed in control and FHL2-null mice. New corneal vessel density was found to be lower in the FHL2-null mice injury group than in the wild-type mice injury group. Western blot analysis showed that VEGF and COX-2 protein levels were higher after chemical injury in FHL2-null mice and wild-type mice. However, the upregulated VEGF protein was significantly lower in the FHL2-null mice than in the wild-type mice. CONCLUSIONS The decreased chemical-induced corneal angiogenesis found in the FHL2-null mice in this study indicated that FHL2 protein plays a role in inhibiting inflammatory angiogenesis.

Infectious scleritis in Taiwan-a 10-year review in a tertiary-care hospital.

Purpose: The aim of this study was to describe the clinical features of infectious scleritis with distinct inciting events and to analyze the factors associated with poor visual outcome. Methods: We retrospectively reviewed the predisposing factors, clinical findings, isolated organisms, complications, and outcomes of patients with infectious scleritis examined between January 2003 and December 2012 at the Chang Gung Memorial Hospital, Taiwan. Results: Forty-five (94%) of 48 patients with infectious scleritis had preceding inciting factors. Prior ocular surgery (40 eyes, 83%), especially pterygium excision (27 eyes, 57%), accounted for the majority of cases; prior accidental injury was found in 5 eyes (10%). The trauma group had a significantly shorter latency and duration of symptoms before diagnosis when compared with the surgery group. Pseudomonas aeruginosa (22 eyes, 46%) was the most commonly identified pathogen, and fungus was detected in 7 eyes (15%). Fungal infections had a longer symptom duration and smaller scleral ulcers at presentations than bacterial infections did. All patients were administered antimicrobials, and early surgical debridement (median 3 days) was performed in 38 eyes (79%). Three eyes (6%) required eyeball removal, and 10 patients (21%) had a posttreatment vision >20/200. With univariate analysis, the identified factors that were significantly associated with poor visual outcomes were visual acuity at presentation worse than 20/200 (P = 0.01), a long duration of hospitalization (P = 0.02), and eyes complicated by scleral thinning (P = 0.034). Conclusions: Infectious scleritis associated with distinct inciting factors or different offending organisms can display divergent characteristics. Intensive antimicrobial treatment and early surgical debridement can salvage eyes.

Shifting Trends in Bacterial Keratitis in Taiwan: A 10-Year Review in a Tertiary-Care Hospital.

Purpose: To investigate the distribution, current trends, and antibiotic susceptibility profiles of bacterial keratitis isolates over 10 years. Methods: We retrospectively reviewed the microbiology records of all corneal scrapings undertaken for cultures at Chang Gung Memorial Hospital from 2003 through 2012. We identified bacterial isolates and verified antibiotic susceptibilities by using the disk diffusion method. The Mantel–Haenszel linear-by-linear association &khgr;2 test was used to detect the trends. Results: We collected 2012 corneal scrapings, and the culture was positive in 992 samples (49.3%), yielding 1282 isolates. Bacterial isolates were identified for 1039 isolates (81.1%), including 533 gram-positive and 506 gram-negative isolates. An increase in the percentage of gram-positive isolates was significant (P = 0.008), as was a decrease in that of gram-negative isolates (P = 0.002). The most common bacterial isolates were Pseudomonas aeruginosa (24.4%) and coagulase-negative Staphylococcus (16.6%). For gram-positive organisms, the susceptibilities were as follows: vancomycin 100%, ciprofloxacin 88.9%, sulfamethoxazole–trimethoprim 86.8%, clindamycin 73.2%, and oxacillin 56.5%. The susceptibility of gram-positive bacteria to clindamycin and oxacillin increased significantly (P = 0.009 and P = 0.001). For gram-negative organisms, the susceptibilities were as follows: ciprofloxacin 93.7%, piperacillin 91.9%, ceftazidime 90.9%, amikacin 88.3%, and gentamicin 84.7%. No change in trend occurred. Conclusions: In Taiwan, we documented an increasing trend in the percentage of gram-positive bacteria. Methicillin-resistant microorganisms accounted for 43.5% of all gram-positive bacteria, but the trend of resistance to oxacillin and clindamycin significantly decreased. Ciprofloxacin continued to be a good empiric antibiotic for treating bacterial keratitis.

Risk Factors and Microbiological Features of Patients Hospitalized for Microbial Keratitis: A 10-Year Study in a Referral Center in Taiwan.

AbstractWe conducted a retrospective, cross-sectional study to analyze predisposing factors, clinical features, and microbiological characteristics of patients with microbial keratitis hospitalized over 10 years.The medical records of 558 patients who were diagnosed with microbial keratitis and admitted to Chang Gung Memorial Hospital (CGMH), a referral center in Taiwan, from January 1, 2003 to December 31, 2012 were reviewed. Demographics, predisposing factors, isolated organisms, treatment, and hospital stay were recorded. Yearly trends were tested using a linear-by-linear association.Contact lens wear was the most common predisposing factor (31.4%), followed by ocular and systemic diseases (26.3%) and trauma (23.5%). Contact lens-related infectious keratitis increased year by year (P = 0.011). Pseudomonas aeruginosa was the most commonly isolated organism (28%), followed by fungi (17.6%) and coagulase-negative Staphylococcus (5.4%). Except for Serratia marcescens, the identified organisms did not change over 10 years. Most bacterial infections were controlled using antimicrobial treatment, but more than half of patients with fungal keratitis required surgical interventions. The mean hospital stay was 13.7 ± 11.5 days. Previous ocular surgery, large ulcer size, nontuberculous myycobacteris infection, and surgery during admission were related to prolonged hospital stay.In Taiwan, contact lens-related pseudomonal keratitis remained the most common cause of microbial keratitis in patients hospitalized from 2003 to 2012.

Late-onset intrascleral dissemination of Stenotrophomonas maltophilia scleritis after pterygium excision.

Purpose: To report a case of pterygium excision-related infectious scleritis with late-onset intrascleral dissemination. Methods: Case report. Results: A 72-year-old female patient was referred for Stenotrophomonas maltophilia scleritis after undergoing pterygium excision 18 years earlier. Surgical debridement and a tectonic corneal patch graft, along with conjunctival flap, were performed to repair the scleral defect after treatment with fortified topical and systemic antibiotics. However, intrascleral dissemination of scleritis occurred 5 months after the initial episode. Conclusions: Intrascleral dissemination of S. maltophilia scleritis after pterygium excision might be delayed because of limited invasiveness and inherent resistance to several antibiotics. Long-term follow-up may be needed to protect against the possibility of late-onset intrascleral dissemination.

Methicillin-Resistant Staphylococcus aureus Ocular Infection in Taiwan: Clinical Features, Genotying, and Antibiotic Susceptibility.

Abstract Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. This observational study aimed to characterize clinical features, antibiotic susceptibility, and genotypes of ocular infections caused by MRSA based on the clinical and molecular definitions of community-associated (CA) and healthcare-associated (HA) strains. Fifty-nine patients with culture-proven S aureus ocular infection were enrolled from January 1, 2010 to December 31, 2011 at Chang Gung Memorial Hospital, Taiwan. Antibiotic susceptibility was verified using disk diffusion/E test. For characterization, staphylococcal cassette chromosome mec (SCCmec), pulsed-field gel electrophoresis (PFGE), multilocus sequence type (MLST), and Panton–Valentine leukocidin (PVL) gene, were performed. MRSA isolates from the patients with HA factors were classified as clinically defined HA-MRSA, and those carrying SCCmec type I to III as molecularly defined HA-MRSA. Thirty-four patients with MRSA ocular infection were identified. The most common clone of CA-MRSA and HA-MRSA isolates was ST59/PFGE type D/SCCmec IV,VT/PVL (+) (n = 12) and CC 239/PFGE type A/SCCmec III, IIIA/PVL(−) (n = 10), respectively. All the 11 patients with molecularly defined HA-MRSA infections and 50% of the 22 patients with molecularly defined CA-MRSA infections were found to have HA factors (P = .005). CA-MRSA tended to cause lid infections, whereas HA-MRSA tended to cause corneal infections. Contrary to HA-MRSA isolates, nearly all the CA-MRSA isolates were susceptible to trimethoprim/sulfamethoxazole and fluoroquinolones under either clinical or molecular classifications. In Taiwan, CA-MRSA isolates exhibited considerably higher susceptibility to fluoroquinolones when compared with HA-MRSA isolates. A strong correlation was observed between the HA factors and molecularly defined HA-MRSA isolates.

Ulcerative keratitis caused by Haemophilus influenzae.

Purpose: To report the clinical course, treatments, antibiotic sensitivities, and visual outcomes for eyes with ulcerative keratitis caused by Haemophlilus influenzae. Methods: The medical records of 10 patients with culture-proven H. influenzae-associated corneal ulcer in a tertiary referral center in a 5-year period (1998-2003) were retrospectively reviewed. Results: The median age was 61 years (range, 2-83 years). The mean follow-up time was 9.4 months (range, 2-31 months). Risk factors such as previous surgeries (5), herpes simplex keratitis (2), leukoma adherens with calcification (1), and exposure keratitis (1) were identified in 9 patients. In vitro testing of the H. influenzae isolates showed that 6 of 10 were resistant to ampicillin; all were sensitive to amoxicillin/clavulanic acid, ceftriaxone, and cefuroxime. All cases responded well to medical antibiotic treatment. Final best spectacle-corrected visual acuity ranged from no light perception to 20/30. Conclusion: H. influenzae is a rare cause of corneal ulceration. Predisposing factors for infection are usually present. Accurate diagnosis and treatment may preserve ocular integrity and visual acuity.