Zhiqun Wang

Corneal nerve structure and function in patients with non-sjogren dry eye: clinical correlations.

PURPOSEnTo evaluate the relationship between the in vivo confocal microscopic (IVCM) morphology of subbasal corneal nerves, corneal sensitivity, and clinical parameters in patients with non-Sjögren dry eye disease (NSDD).nnnMETHODSnForty-three patients with NSDD and 14 healthy age- and sex-matched control subjects were included. Each patient underwent an evaluation of ocular surface disease symptoms using the Ocular Surface Disease Index (OSDI); tear film break-up time (TBUT); corneal and conjunctival staining (Oxford scale); the Schirmer test; corneal sensation testing using the Cochet-Bonnet esthesiometer; and corneal subbasal nerve analysis with IVCM. One eye of each subject was included in the study.nnnRESULTSnMean corneal sensitivity was significantly lower in the NSDD group as compared with the control group (P = 0.014). Corneal subbasal nerves showed significant changes in NSDD patients as compared with normal subjects: lower density (P < 0.001); increased tortuosity (P < 0.001); number of beadings (P < 0.001); and width (P = 0.041). In patients with NSDD, corneal subbasal nerve density was correlated to age (r = -0.352, P = 0.021); the Oxford scale (r = -0.486, P = 0.01); and central corneal sensitivity (r = 0.383, P = 0.041). The maximum length of nerve fibers within a frame (MaxL) was correlated to the OSDI (r = -0.265, P = 0.019) and the Oxford scale (r = -0.307, P = 0.039). In multivariate analysis after adjustment for age, corneal subbasal nerve density remained correlated to the Oxford score (P < 0.001). The Oxford score was also correlated to central corneal sensitivity (r = -0.304, P = 0.042).nnnCONCLUSIONSnNSDD patients have both structural and functional alterations of subbasal corneal nerves and these changes are related to the severity of dry eye.

Acanthamoeba Keratitis: Clinical Characteristics and Management

PURPOSEnTo review characteristics of clinical features in 260 eyes with Acanthamoeba keratitis (AK) from 1991 to 2013.nnnMETHODSnWe retrospectively analyzed 260 eyes from 259 patients diagnosed with Acanthamoeba keratitis (AK) by smear and/or culture and/or laser confocal microscopy between 1991 and 2013 at Beijing Tongren Eye Center. Patient data included age, gender, profession, predisposing risk factors, clinical presentation, treatment, therapy effect, and course of disease.nnnRESULTSnThe most common risk factor in this study was ocular trauma (53.1%), followed by contact lens wear (29.8%). Most of the AK patients were farmers (50.8%), and students (23.8%) formed the second largest group of AK patients. Most cases (77.8%) were classified as advanced stage AK at initial presentation; only a few patients (5.6%) were diagnosed with early stage disease. Of 90 cases, 77 (85.6%) had salt-like dense infiltrate dots on the corneal ulcer, 54 cases (61.1%) had groove-shaped corneal melting around the corneal ulcer, and 37 cases(41.1%) had classic ring infiltrate. Nine cases experienced improved conditions at the beginning of treatment, which subsequently worsened, and then improved gradually. Treatments were administered according to the disease stage. After topical anti-amoeba drug therapy, 48 of 90 cases (53.3%) were cured with corneal scarring remaining; mean duration of treatment was 5 months.nnnCONCLUSIONnSalt-like dense infiltrate dots and groove-shaped corneal melting may serve as useful clues in the diagnosis of AK, in addition to radial neuritis and ring infiltration. Some patients with AK may experience a worsened condition after early improvement with anti-amoeba drug therapy, and then improve gradually.

BIOFILM-FORMING CAPACITY OF STAPHYLOCOCCUS EPIDERMIDIS, STAPHYLOCOCCUS AUREUS, AND PSEUDOMONAS AERUGINOSA FROM OCULAR INFECTIONS

PURPOSEnTo investigate the biofilm-forming capacity of Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa from ocular infections.nnnMETHODSnS. epidermidis strains, S. aureus strains, and P. aeruginosa strains were isolated from patients with ocular infections between 2009 and 2011. The biofilm-forming capacity of these bacteria was examined using Congo red agar (CRA) and microtiter plate assays. The biofilm-forming related genes, icaA, of S. epidermidis and S. aureus, and pslA, of P. aeruginosa, were detected using PCR. Additionally, the morphology of biofilms was observed using a scanning electron microscopy (SEM).nnnRESULTSnOf the isolated S. epidermidis strains, 34.38% were CRA positive, 28.13% were adherence positive using the microtiter plate assay, and 40.63% carried the icaA gene. Of the isolated S. aureus strains, 55.56% were CRA positive, 51.90% were adherence positive, and 11.11% carried the icaA gene. None of the P. aeruginosa strains were phenotypic positive using CRA and microtiter plate assays, whereas 31.03% contained the pslA gene. There were significant differences between the three species when the biofilm-forming capacity of the strains was compared using the CRA method (P < 0.01) and the microtiter plate assay method (P < 0.01).nnnCONCLUSIONSnOphthalmic isolates of S. epidermidis and S. aureus could produce biofilms in vitro, whereas clinical strains of P. aeruginosa could not. The bacterial strains possess the genetic ability to produce biofilms, but that does not necessarily mean that biofilms will be produced. The knowledge of the process of bacterial adhesion suggests that a timely and appropriate intervention strategy be implemented in the early stages of biofilm-mediated infections.

Keratitis-Associated Fungi Form Biofilms with Reduced Antifungal Drug Susceptibility

PURPOSEnTo investigate the biofilm-forming capacity of Fusarium solani, Cladosporium sphaerospermum, and Acremonium implicatum, and the activities of antifungal agents against the three keratitis-associated fungi.nnnMETHODSnThe architecture of biofilms was analyzed using scanning electron microscopy and confocal scanning laser microscopy (CSLM). Susceptibility against six antifungal drugs was measured using the CLSI M38-A method and XTT reduction assay.nnnRESULTSnTime course analyses of CSLM revealed that biofilm formation occurred in an organized fashion through four distinct developmental phases: adhesion, germling formation, microcolony formation, and biofilm maturation. Scanning electron microscopy revealed that mature biofilms displayed a complex three-dimensional structure, consisting of coordinated network of hyphal structures glued by the extracellular matrix (ECM). The antifungal susceptibility testing demonstrated a time-dependent decrease in efficacy for all six antifungal agents as the complexity of fungal hyphal structures developed. Natamycin (NAT), amphotericin B (AMB), and NAT were the most effective against F. solani, C. sphaerospermum, and A. implicatum biofilm, respectively.nnnCONCLUSIONSnCorneal isolates of F. solani, C. sphaerospermum, and A. implicatum could produce biofilms that were resistant to antifungal agents in vitro.

Effect of Ultraviolet Light Irradiation Combined with Riboflavin on Different Bacterial Pathogens from Ocular Surface Infection

In order to study Staphylococcus epidermis and Staphylococcus aureus in vitro viability after the exposure to ultraviolet (UV) light and riboflavin, twelve strains of Staphylococcus epidermis and twelve strains of Staphylococcus aureus were isolated from patients with bacterial keratitis. The growth situation of Staphylococcus epidermidis and Staphylococcus aureus under different experimental conditions was qualitatively observed. The number of colonies surviving bacteria was counted under different UV light power and different exposure time. The experiment showed that there was no inhibition effect on the growth of bacteria using riboflavin alone. In UV alone group and UV-riboflavin group, inhibition effect on the bacteria growth was found. The UV-riboflavin combination had better inhibition effect on bacteria than UV irradiation alone. The amount of bacteria in the UV-riboflavin group was decreased by 99.1%~99.5% and 54.8%~64.6% in the UV alone group, when the UV light power was 10.052u2009mW/cm2 and the irradiation time was 30u2009min. Moreover, with the increase of the UV power or irradiation time, the survival rates of bacteria were rapidly reduced. Compared with Staphylococcus aureus, Staphylococcus epidermis was more easily to be killed under the action of UV light combined with riboflavin.

A survey of contact lens-related complications in a tertiary hospital in China

PURPOSEnTo describe the type of complications related to contact lens (CL) wear in a tertiary hospital in XX, China.nnnMETHODSnA retrospective study of 141 patients who complained discomfort after wearing contact lens on an outpatient basis of XX Hospital were conducted from the January 2012 to December 2015. The data included patients demographics, lens type, history, slit-lamp examination, reports of corneal scrapings, culture, and examination of in vivo confocal microscopy. Binary logistic regression was used to analyse the possible factors which were associated with more severe corneal complications and superficial punctuate keratitis (SPK).nnnRESULTSnAbout 86.52% were female and 13.48% were male, the age varied between 12 and 56 years old. Of the 141 patients, 82.27% were soft CL wearers, 2.84% were rigid gas permeable lens (RGP) wearers, and 14.89% patients used overnight orthokeratology. The most common complication was dry eye (36.88%), followed by SPK (36.17%) during these cases. Blepharitis and meibomian gland dysfunction (MGD) were noted in 31.91% of cases. Microbial keratitis was seen in 15 patients including 7 cases of Acanthamoeba keratitis. Age was a significant factor to be a case of corneal infection or inflammation [Exp (B)was 0.918, p=0.030], MGD and blepharitis was found to be significantly associated with being a case of SPK [Exp(B)was2.276, p=0.047].nnnCONCLUSIONSnThe commonest complication was dry eye in this study, followed by SPK. Lid margin and meibomain gland should be paid attention to before contact lens prescription. Younger CL wearers need follow-up examinations.

Biofilm-Forming Capacity ofStaphylococcus epidermidis,Staphylococcus aureus, andPseudomonas aeruginosafrom Ocular Infections

PURPOSEnTo investigate the biofilm-forming capacity of Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa from ocular infections.nnnMETHODSnS. epidermidis strains, S. aureus strains, and P. aeruginosa strains were isolated from patients with ocular infections between 2009 and 2011. The biofilm-forming capacity of these bacteria was examined using Congo red agar (CRA) and microtiter plate assays. The biofilm-forming related genes, icaA, of S. epidermidis and S. aureus, and pslA, of P. aeruginosa, were detected using PCR. Additionally, the morphology of biofilms was observed using a scanning electron microscopy (SEM).nnnRESULTSnOf the isolated S. epidermidis strains, 34.38% were CRA positive, 28.13% were adherence positive using the microtiter plate assay, and 40.63% carried the icaA gene. Of the isolated S. aureus strains, 55.56% were CRA positive, 51.90% were adherence positive, and 11.11% carried the icaA gene. None of the P. aeruginosa strains were phenotypic positive using CRA and microtiter plate assays, whereas 31.03% contained the pslA gene. There were significant differences between the three species when the biofilm-forming capacity of the strains was compared using the CRA method (P < 0.01) and the microtiter plate assay method (P < 0.01).nnnCONCLUSIONSnOphthalmic isolates of S. epidermidis and S. aureus could produce biofilms in vitro, whereas clinical strains of P. aeruginosa could not. The bacterial strains possess the genetic ability to produce biofilms, but that does not necessarily mean that biofilms will be produced. The knowledge of the process of bacterial adhesion suggests that a timely and appropriate intervention strategy be implemented in the early stages of biofilm-mediated infections.

Biofilm-Forming Capacity of Staphylococcus epidermidis , Staphylococcus aureus , and Pseudomonas aeruginosa from Ocular InfectionsBiofilm-Forming Capacity of Human Flora Bacteria

PURPOSEnTo investigate the biofilm-forming capacity of Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa from ocular infections.nnnMETHODSnS. epidermidis strains, S. aureus strains, and P. aeruginosa strains were isolated from patients with ocular infections between 2009 and 2011. The biofilm-forming capacity of these bacteria was examined using Congo red agar (CRA) and microtiter plate assays. The biofilm-forming related genes, icaA, of S. epidermidis and S. aureus, and pslA, of P. aeruginosa, were detected using PCR. Additionally, the morphology of biofilms was observed using a scanning electron microscopy (SEM).nnnRESULTSnOf the isolated S. epidermidis strains, 34.38% were CRA positive, 28.13% were adherence positive using the microtiter plate assay, and 40.63% carried the icaA gene. Of the isolated S. aureus strains, 55.56% were CRA positive, 51.90% were adherence positive, and 11.11% carried the icaA gene. None of the P. aeruginosa strains were phenotypic positive using CRA and microtiter plate assays, whereas 31.03% contained the pslA gene. There were significant differences between the three species when the biofilm-forming capacity of the strains was compared using the CRA method (P < 0.01) and the microtiter plate assay method (P < 0.01).nnnCONCLUSIONSnOphthalmic isolates of S. epidermidis and S. aureus could produce biofilms in vitro, whereas clinical strains of P. aeruginosa could not. The bacterial strains possess the genetic ability to produce biofilms, but that does not necessarily mean that biofilms will be produced. The knowledge of the process of bacterial adhesion suggests that a timely and appropriate intervention strategy be implemented in the early stages of biofilm-mediated infections.