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1.
The development of polymers with different surface properties and surface modifications of intraocular lenses (IOL) should reduce foreign body reactions after implantation by reducing the surface hydrophobicity of the lenses. It was examined how far such surface variations influenced the adhesiveness of bacteria. The most common organism isolated from cases of postoperative endophthalmitis is Staphylococcus epidermidis. For this reason, three strains of this species, the type strain ATCC 14990 and two clinical isolates (8687, 6579 I), with different hydrophobic surfaces, were studied. IOL made of PMMA, silicone, and a copolymer as well as PMMA lenses with modified surfaces (unpolished, polished, silanized, and heparinized) were used. Bacteria were radiolabelled with 3H-thymidine and the adherent bacteria were calculated per mm2 of lens surface. The three strains adhered better to the unpolished surface of silicone than to PMMA. Treatment of PMMA surface by polishing diminished the differences between the strains. An influence of hydrophobic interactions on the adherence of S. epidermidis ATCC 14990 was demonstrated. The adherence of this hydrophobic type strain was clearly reduced by heparinization of the PMMA surface. In contrast, the hydrophilic catheter isolate 6579 I adhered better to modified surfaces. This strain differed clearly in its PFGE pattern from both hydrophobic strains. Hydrophobic interactions play a role in the bacterial adherence to intraocular lenses in vitro and in vivo. Modifications of polymer surfaces, however, can result in rather different effects depending on the bacterial surface composition and properties.  相似文献   

2.
BACKGROUND: A major goal in research on intraocular lenses (IOL) is the development of new polymers and modifications to reduce foreign-body reactions after implantation. This effect may be achieved by a reduction in the surface hydrophobicity of the polymers. To illustrate the influence of surface modifications on bacterial adhesiveness, the most often isolated organism in "low-grade" postoperative endophthalmitis, Staphylococcus epidermidis, was used. MATERIALS AND METHODS: For this reason three strains of this species, the type strain ATCC 14990 and two clinical isolates (8687, 6579 I) with different hydrophobic surface properties were studied. IOL, used in the experiments were either made of PMMA or silicone with modified surfaces (unpolished, polished, heparinized). The adhesiveness of H3-thymidin-labeled bacteria was calculated/mm2 of lens surface. Each experiment was performed in triplicate and repeated three times. RESULTS: The hydrophobic-type strain showed stronger adherence to unpolished PMMA surface (8000 bacteria per mm2) compared to the polished (5200 bacteria/mm2). In contrast, the hydrophilic strain adhered with 2000 bacteria/mm2 to the unpolished and with 4200 bacteria/mm2 to the polished surface. Polishing PMMA lenses diminished the differences between the three strains. However, surface passivation of silicone lenses increased the adhesion rate of the hydrophilic strain up to 9600 bacteria/mm2. Treatment of PMMA lenses with heparin increased the adhesiveness of the hydrophilic strain and reduced the adhesion rate of the hydrophobic type strain to 250 bacteria/mm2. CONCLUSIONS: It was demonstrated that bacterial adherence to IOL also involves hydrophobic interactions. Obviously, however, that adherence reflects a complex of interactions between the two surfaces.  相似文献   

3.
PURPOSE: The 193-nm argon fluoride excimer laser can remove corneal scars and smooth corneal irregularities, obviating corneal transplantation. We conducted a prospective multicenter trial of excimer laser phototherapeutic keratectomy for corneal vision loss as a basis for Food and Drug Administration premarket approval. METHODS: We treated 232 eyes of 211 patients with corneal vision loss. All had corneal pathology in the anterior 100 microns of the stroma. Mean postoperative follow-up was 10 +/- 8 months. The primary outcome variable was change in best spectacle-corrected visual acuity. RESULTS: At postoperative month 12, best spectacle-corrected visual acuity improved in 46 (45%) of 103 eyes and worsened in nine (9%) of 103 eyes by 2 or more Snellen lines. Best spectacle-corrected visual acuity improved by a mean of 1.6 +/- 2.8 Snellen lines (95% confidence interval, 1.1 to 2.1 lines). Every postoperative visit confirmed statistically significant improvement of mean best spectacle-corrected acuity. At month 12, treated eyes had a mean hyperopic shift in refraction of 0.87 diopter and a mean reduction in astigmatism of 0.36 diopter. Treatment appeared most effective in eyes with hereditary corneal dystrophies, Salzmann's nodular degeneration, and corneal scars, and least effective in eyes with calcific band keratopathy. Complications included recurrence of underlying pathology, corneal graft rejection, and bacterial keratitis. CONCLUSIONS: Argon fluoride excimer laser phototherapeutic keratectomy is effective, with relatively few complications, for treating vision loss from corneal opacification or irregularity. Efficacy, however, varies widely depending upon individual eyes and underlying diagnoses.  相似文献   

4.
Adhesion of staphylococcal cells to intraocular lenses coated with heparin was studied under in vitro flow conditions (280 microl min(-1)) at 37 degrees C. The intraocular lenses were incubated with human cerebrospinal fluid for 1 h or with cerebrospinal fluid including 0.50% plasma for 12 h, prior to bacterial challenge. Two strains of Staphylococcus epidermidis selected for this study, were isolated from biomaterial-associated infections. Bacterial adhesion was quantitated by bioluminescence and visualized by fluorescence microscopy of acridine orange stained bacteria. Surface coating with heparin significantly decreased bacterial adhesion of both strains after incubation with cerebrospinal fluid including 0.50% plasma for 12 h (p = 0.0209). However, no difference in bacterial adhesion was obtained between intraocular lenses with and without heparin, after incubation with cerebrospinal fluid for 1 h (p = 0.327). Microscopy showed that more bacteria were present on intraocular lenses without heparin than on intraocular lenses with heparin. The results show that preincubation with a proteinaceous fluid influences subsequent bacterial adhesion to the polymer surface. The results suggest that IOLs with heparin coating may be less prone to bacterial adhesion under perfusion conditions after surface conditioning in human CSF with 0.50% plasma and a preincubation period of 12 h. Heparin coating might be a valuable tool to decrease implant-associated bacterial endophthalmitis.  相似文献   

5.
BACKGROUND: Although Gram negative as well as Gram positive bacteria participate in febrile episodes of neutropenic patients, in particular recently the ratio of Gram positive bacteria is increasing. The objective of the present work was to investigate the incidence and antibiotic resistance of pathogenic bacterial agents in neutropenic patients. METHODS AND RESULTS: The presence of bacteria was investigated in 446 neutropenic patients hospitalized at the Haematological Clinic in 1995. Haemocultures (apparatus Bact/Alert 120, cultivation media Organon-Teknika) and urine were examined. The sensitivity for antibiotics was tested by the standard dilution micromethod. In blood most frequently Staphylococcus epidermidis was isolated (45.4%), coagulase-negative strains of Staphylococcus haemolyticus, Staphylococcus hominis and Staphylococcus saprophyticus (14.4%), Acinetobacter calcoaceticus-baumannii (complex 6.3%) and Pseudomonas aeruginosa (6.3%). In urine the following were detected: Staphylococcus epidermidis (36.5%), Enterococcus sp. (14.5%), Escherichia coli (13.1%), Enterococcus faecalis (11.6%) and Enterococcus solitarius (6.5%). In all strains resistance to antibiotics and chemotherapeutic drugs was assessed. CONCLUSIONS: Investigation of the frequency of different bacterial species, along with monitoring of the resistance is an essential prerequisite of initial antibiotic therapy of febrile episodes in neutropenic patients.  相似文献   

6.
An analysis of central microbial keratitis with respect to etiology, recovery, complications and visual outcome was carried out in Gothenburg, Sweden, during a 3-year period. Gram positive bacteria were found in 22 out of 48 cases; Staphylococcus aureus and Staphylococcus epidermidis accounted for more than 50% of these Gram positive cases. Pseudomonas was the most common Gram negative bacterium. No case with etiology of fungus was found. The contact lens wearers showed mainly the same bacterial spectrum as non-wearers. The initial 'shotgun' therapy with cefuroxime and gentamycin seemed adequate for this bacterial spectrum. Seventy percent of the eyes healed within 3 weeks. Contact lens wear and trauma were found to be the two major predisposing factors in the cases with microbial keratitis. The lens wearers had shorter recovery times than the non wearers. The visual results after one month were good in 50% of the eyes, and another 12% attained useful vision.  相似文献   

7.
The effect of extracts from Staphylococcus aureus and Staphylococcus epidermidis on bone matrix production were assessed by analyzing the biosynthesis of osteocalcin and Type I collagen in a human osteoblastic osteosarcoma cell line (MG-63). In MG-63 cells, extracts from Staphylococcus aureus and Staphylococcus epidermidis decreased 1,25(OH)2-vitamin D3 stimulated osteocalcin biosynthesis, and insulin-like growth factor I induced production of Type I collagen in a concentration dependent manner. The basal rate of osteocalcin and Type I collagen formation was unaffected by the bacterial extracts. The inhibitory effect of the bacteria on osteocalcin biosynthesis was seen after 24 hours of treatment and was maintained for at least 96 hours. The extracts of Staphylococcus aureus and Staphylococcus epidermidis enhanced prostaglandin E2 formation in the MG-63 cells. Abolition of the prostaglandin E2 response by treatment with indomethacin and flurbiprofen did not affect bacteria induced inhibition of osteocalcin production. Stimulation of osteocalcin biosynthesis by 1,25(OH)2-vitamin D3 was associated with a decreased rate of cell proliferation. The inhibitory action of the bacterial extracts was not linked to any inhibition of [3H]-thymidine incorporation into deoxyribonucleic acid. These data show that extracts of Staphylococcus aureus and Staphylococcus epidermidis have the ability to inhibit the biosynthesis of bone matrix proteins by a nonprostaglandin and noncytotoxic dependent mechanism and suggest that bone loss in inflammatory processes containing Staphylococcus aureus or Staphylococcus epidermidis may not be caused only by enhanced bone resorption but also by decreased bone formation.  相似文献   

8.
Excimer laser photorefractive keratectomy and excimer laser in situ keratomileusis are relatively new treatment modalities that can be used to correct refractive errors of the eye. They are most commonly used to correct myopia (nearsightedness) but can also be used to correct hyperopia (farsightedness) and astigmatism. The excimer laser alters the refractive state of the eye by removing tissue from the anterior cornea through a process known as photoablative decomposition. This process uses ultraviolet energy from the excimer laser to disrupt chemical bonds in the cornea without causing any thermal damage to surrounding tissue. The modified anterior corneal surface enables light to be focused on the retina, thereby reducing or eliminating the dependence on glasses and contact lenses. We discuss in detail all aspects of excimer laser refractive surgery--techniques, indications and contraindications, clinical outcomes, and complications.  相似文献   

9.
PURPOSE: To measure anterior chamber bacterial and fungal contamination at the beginning and end of cataract surgery with intraocular lens (IOL) implantation in a large series of patients and to determine the influence of preoperative treatment and operative technique on contamination. SETTING: Department of Ophthalmology, County Hospital of Salzburg, Austria. METHODS: This prospective study comprised 700 consecutive patients having planned cataract extraction (511 phacoemulsification, 189 extracapsular cataract extraction [ECCE]). Thirty-four patients required an anterior vitrectomy; 8 myopic patients did not receive an IOL. A preoperative smear and two intraoperative (at the beginning and end of surgery) anterior chamber aspirates were obtained from each patient. Postoperative smears were obtained at discharge. Three preoperative treatments were evaluated: no lacrimal system irrigation, no topical antibiotic (n = 282); lacrimal system irrigation with balanced saline solution, no topical antibiotic (n = 243); lacrimal system irrigation, antibiotic (neomycin) eyedrops (n = 175). All patients received topical indomethacin twice a day preoperatively. RESULTS: Preoperative conjunctival smears showed bacterial growth in 76.6% of eyes, with coagulase-negative staphylococci (75%) the most common bacteria. Anterior chamber aspirates were culture positive in 14.1% at the beginning and in 13.7% at the end of surgery, with coagulase-negative staphylococci and corynebacteria the most common. Contamination rates of conjunctival smears taken at discharge were significantly lower (35%) than those taken preoperatively. There was no statistically significantly higher risk of anterior chamber contamination in eyes having ECCE than in those having phacoemulsification. Preoperative treatment did not statistically significantly influence intraoperative aqueous humor contamination rates. There were no cases of acute postoperative endophthalmitis. CONCLUSION: Bacteria entered the anterior chamber during cataract extraction and remained there at the end of surgery in a significant percentage of patients. Surgical technique, preoperative antibiotics, and preoperative lacrimal system irrigation had no statistically significant effect on contamination.  相似文献   

10.
Pharmaceutical agents and irrigating solutions are widely used in both optometric and ophthalmologic practices. Contamination of these containers or solutions could possibly pose some risk of infection to a patient. We set out to investigate the possible contamination of a representative sample of these containers in small office practices. Representative bottles of two diagnostic pharmaceutical agents and an irrigating solution were obtained from primary care optometric and ophthalmologic practices in the San Francisco-Oakland Bay area. These bottles were tested to investigate the rate of contamination and to identify the types of microorganisms in the contaminated solutions. Sixty total samples (proparacaine, tropicamide, and an irrigating solution) were randomly cultured, and 11.7% of the samples showed contamination. Pseudomonas cepacia, Staphylococcus epidermidis, Pseudomonas putida, and Streptococcus species were the predominant organisms isolated from the contaminated bottles. In addition, 17 of the original 60 containers were further cultured for investigation of the dried residue particles around the threads of the containers. Of these 17 containers, 13 (76.5%) tested positive for Staphylococcus and Micrococcus species.  相似文献   

11.
Bacterial biofilm formation on contact lenses (CLs), and CL storage cases may be a risk factor for CL-associated corneal infection and may explain the persistence of organisms in CL storage cases. This study evaluated biofilm formation on, and microbial contamination of, CLs and CL storage cases from patients with microbial keratitis. Contact lenses and CL storage cases from 20 wearers with microbial keratitis were sampled microbiologically and visualized using scanning electron microscopy (SEM). Culture results from the cornea were also noted. Bacterial biofilm was present more frequently (P < 0.05) on CL storage case surfaces (17/20) compared with CL surfaces (11/20) and biofilm density was significantly greater on case surfaces (P < 0.05). There was no association between poor compliance and microbial contamination of the CL storage case, nor between poor compliance and biofilm formation or density on the CL or CL storage case. Biofilm formation occurred equally frequently with hydrogen peroxide and chlorine release care systems. Microbial keratitis in CL wearers is frequently associated with bacterial biofilm in the CL storage case. Despite the use of current CL disinfection systems, the CL storage case is a favourable environment for proliferation of certain organisms. Biofilm on CLs may prolong the retention time of organisms at the ocular surface and increase their potential pathogenicity.  相似文献   

12.
The advent of the excimer laser has brought about the potential for improved vision in many individuals with myopia and astigmatism. However, photoastigmatic refractive keratectomy (PARK) remains a matter of controversy. The purpose of our study was to determine the predictability of VISX 20/20 excimer laser photorefractive keratectomy in the treatment of myopic astigmatism. PATIENTS AND METHODS: Our study comprised 31 eyes of 22 patients with myopic astigmatism. All patients underwent treatment with a VISX 20/20 excimer laser and were followed up for 6 months. Complete 12-month follow-up data were available from 18 eyes. Park was performed in eyes with myopia between -1.5 and -10.0 D and with astigmatism between -0.5 and -5.5 D. Thus, the corresponding spherical equivalent ranged from -1.75 to -10.5 D. RESULTS: Six months postoperatively, 21/31 (62%) eyes were within +/- 1.0 D of the target refraction and 13/31 (42%) within +/- 0.5 D of the target refraction. In 13 of 15 eyes (87%) with myopia less than -6.0 D, an uncorrected visual acuity of at least 0.8 was noted. In eyes with myopia greater than -6.0 D, 9/16 (56%) showed an uncorrected visual acuity of at least 0.5. Six months after PARK, an increase of one line on the Snellen Visual Acuity Chart was observed in 8/31 (26%) and an increase of two lines was noted in eyes 3/31 (10%). One of 31 eyes (3%) showed an increase of three lines. A decrease in visual acuity of 1 line on the Snellen Visual Acuity Chart was found in 4/31 (13%), and in 3/31 eyes (10%) a decrease of 2-4 lines was noted. Overall, we observed a statistically significant reduction of astigmatism from 1.93 +/- 1.43 D to 0.93 +/- 0.63 D. Reduction of corneal astigmatism less than -1.25 D was not statistically significant. In eyes with astigmatism ranging from -1.25 to -2.5 D or greater than -2.75 D, a significant reduction of the mean astigmatism was noted. The postoperative regression of astigmatic correction was low. However, an axis shift of more than 15 degrees was found in 42%/35% of eyes by subjective refraction (miosis/cycloplegia) and in 33% in corneal topography. No central islands were noted. CONCLUSION: Photoastigmatic refractive keratectomy (PARK) constitutes a potential means of correcting myopic astigmatism. In eyes with astigmatism greater than -1.0 D a significant reduction of 60% of the mean astigmatism was noted. However, the considerable proportion of eyes with a postoperative axis shift greater than 15 degrees and a decrease in visual acuity of two or more lines indicates that further research is needed on excimer laser surgery to improve the reliability and safety.  相似文献   

13.
The purpose of this study was to determine which corneal curvature values most closely correlated to change in subjective manifest refraction following excimer laser photorefractive keratectomy (PRK). METHODS: Excimer laser PRK was performed on ten eyes of ten patients (mean age: 37.3 years). Preoperative refractive errors ranged from -2.25 to -8.75 diopters. Preoperatively and 1 month postoperatively, we determined the spherical equivalent of the manifest refraction (corrected for a 12 mm vertex distance) and measured corneal power using standard keratometry (Bausch and Lomb keratometer) and computerized videokeratography (EyeSys Corneal Analysis System). We collected five corneal values: standard keratometry, videokeratography-derived simulated keratometric readings calculated using the axial, instantaneous and refractive formulas, and corneal refractive power over the central 3-mm zone (effective refractive power); apart from the traditional refractive index of the cornea (n = 1.3375), we used the refractive value of the anterior corneal stroma (n = 1.376). For each of the five corneal values, we subtracted the change in corneal power from the change in manifest refraction and calculated the means and standard deviations. RESULTS: The mean differences between the refraction and the corneal values for a refractive index of 1.3375/1.376 were: 0.89 +/- 0.54*/1.26 +/- 0.59* for standard keratometry; 1.64 +/- 0.75*/1.37 +/- 0.7*, 4.03 +/- 1.86*/ 3.86 +/- 1.87*, and 1.16 +/- 0.76*/0.91 +/- 0.74* for the axial, instantaneous, and refractive videokeratography values, respectively; and 0.83 +/- 1.03*/0.39 +/- 1.08 for the effective refractive power (*,p < 0.05). CONCLUSIONS: In our series, only the values for the effective refractive power, calculated with the refractive Index of the anterior stroma of the cornea, were not statistically different from the change in manifest refraction.  相似文献   

14.
PURPOSE: To support the hypothesis that Acanthamoeba is not a unique cause of amebic keratitis, we report a case of amebic keratitis in which viable Acanthamoeba could not be isolated from corneal tissue. Vahlkampfia and Hartmannella, two other genera of free-living ameba, were isolated, however, using prolonged culture. METHODS: A 24-year-old wearer of soft contact lenses had keratitis. Extensive histologic and microbiologic investigations were performed on corneal scrape, biopsy, and keratoplasty tissue. Contact lenses, storage case, and the home water supply, where contact lens hygiene was practiced, were examined for the presence of micro-organisms. RESULTS: No viruses, pathogenic bacteria, or fungi were detected from corneal tissue samples. Amebae were observed using light and electron microscopy, but these could not be unequivocally classified using immunocytochemical staining. Viable Vahlkampfia and Hartmannella, but no Acanthamoeba, were isolated from the corneal biopsy sample. Indirect immunofluorescence with a range of polyclonal rabbit antisera raised against axenically cultivated stains of the three amebal genera was unhelpful because of cross-reactivity. A diverse range of micro-organisms was present within the storage case, including the three amebal species. Amebic cysts also were associated with the contact lens. CONCLUSION: A mixed non-Acanthamoeba amebic keratitis has been identified in a wearer of soft contact lenses where lack of storage case hygiene provided the opportunity for the free-living protozoa Vahlkampfia and Hartmannella to be introduced to the ocular surface. When Acanthamoeba-like keratitis occurs, but where Acanthamoeba cannot be isolated using conventional laboratory culture methods, alternate means should be used to identify other amebae that may be present. Polyclonal immunofluorescent antibody staining was unreliable for generic identification of pathogenic free-living amebae in corneal tissue.  相似文献   

15.
Our previous studies identified two iron-regulated cytoplasmic membrane proteins of 32 and 36 kDa expressed by both Staphylococcus epidermidis and Staphylococcus aureus. In this study we show by Triton X-114 phase partitioning and tritiated palmitic acid labelling that these proteins are lipoproteins which are anchored into the cytoplasmic membrane by their lipid-modified N termini. In common with those of some other gram-positive bacteria, these highly immunogenic lipoproteins were released from the bacterial cell into the culture supernatants, with release being promoted by growth of the bacteria under iron-restricted conditions. Immunoelectron microscopy with a monospecific rabbit antiserum to the 32-kDa S. epidermidis lipoprotein showed that the majority of the antigen was distributed throughout the staphylococcal cell wall. Only minor quantities were detected in the cytoplasmic membrane, and exposure of the lipoprotein on the bacterial surface was minimal. A monoclonal antibody raised to the 32-kDa lipoprotein of S. aureus was used in immunoblotting studies to investigate the conservation of this antigen among a variety of staphylococci. The monoclonal antibody reacted with polypeptides of 32 kDa in S. epidermidis and S. aureus and of 40 kDa in Staphylococcus hominis. No reactivity was detected with Staphylococcus lugdunensis, Staphylococcus cohni, or Staphylococcus haemolyticus. The gene encoding the 32-kDa lipoprotein from S. epidermidis has been isolated from a Lambda Zap II genomic DNA library and found to be a component of an iron-regulated operon encoding a novel ABC-type transporter. The operon contains three genes, designated sitA, -B, and -C, encoding an ATPase, a cytoplasmic membrane protein, and the 32-kDa lipoprotein, respectively. SitC shows significant homology both with a number of bacterial adhesins, including FimA of Streptococcus parasanguis and ScaA of Streptococcus gordonii, and with lipoproteins of a recently described family of ABC transporters with proven or putative metal ion transport functions. Although the solute specificity of this novel transporter has not yet been determined, we speculate that it may be involved in either siderophore- or transferrin-mediated iron uptake in S. epidermidis.  相似文献   

16.
PURPOSE: To investigate the aerobic and anaerobic microbiology of dacryocystitis. METHOD: Retrospective review of the 62 clinical and microbiologic records collected between 1980 and 1990. RESULTS: Aerobic or facultative bacteria were recovered in 32 cases (52%), anaerobic bacteria only in 20 cases (32%), mixed aerobic and anaerobic bacteria in seven cases (11%), and fungi in three cases (5%). A total of 94 organisms (1.5 per specimen), which included 56 aerobic or facultative anaerobic organisms, 35 anaerobic organisms, and three fungi, were recovered. The predominant aerobic and facultative bacteria were Staphylococcus aureus (15 isolates), Staphylococcus epidermidis (13 isolates), and Pseudomonas species (seven isolates). The most frequently recovered anaerobes were Peptostreptococcus species (13 isolates), Propionibacterium species (12 isolates), Prevotella species (four isolates), and Fusobacterium species (three isolates). The predominant fungus was Candida albicans (two isolates). Polymicrobial infection was present in 28 cases (45%). CONCLUSION: These data highlight the potential importance of anaerobic bacteria in dacryocystitis.  相似文献   

17.
OBJECTIVE: The purpose of this study was to present the microbiology and clinical features of six children with superficial suppurative thrombophlebitis (SST) caused by anaerobic bacteria. METHODS: A retrospective review of microbiological and clinical data was undertaken. RESULTS: Anaerobic bacteria alone were recovered in four instances, and they were mixed with facultative bacteria in two. There were 12 bacterial isolates (10 anaerobic and 2 facultatives). The bacteria were Peptostreptococcus species (four isolates), Prevotella species (three), and one isolate each of Fusobacterium nucleatum, Propionibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis. SST at an intravenous infusion site developed in all but one patient. One patient sustained trauma to the leg, and cellulitis developed. Anaerobes of oral origin (Prevotella and Fusobacterium species) were recovered in scalp vein SST, and of gastrointestinal origin (Bacteroides fragilis) in a lower extremity SST. CONCLUSION: This study highlights the potential importance of anaerobic bacteria in children with SST.  相似文献   

18.
BACKGROUND: We report on the case of a 46-year-old female who presented with delayed microbial keratitis 10 years after uncomplicated radial keratotomy. METHODS: The pre- and postoperative clinical record was reviewed following her presentation to the Corneal Clinic. Slit-lamp examination revealed a stromal inflammatory infiltrate at the site of an earlier radial keratotomy incision. The lesion was scraped and a coagulase-negative Staphylococcus aureus was cultured in enrichment broth. RESULTS: The keratitis was treated successfully with combination fortified topical antibiotics without loss of vision. CONCLUSIONS: Although microbial keratitis is a well documented complication of incisional refractive procedures, it is rarely encountered as late as one decade after surgery. Patients should be warned of this possibility and the need for prompt treatment.  相似文献   

19.
The effect of various hand washing regimens on transfer of bacterial contaminants from the hands to a hydrogel contact lenses was evaluated. Each of 47 subjects performed 5 different hand washing procedures, and then handled a new, sterile hydrogel contact lens. The lenses were cultured to determine colony-forming units (CFUs) and microbial identity. Median CFUs on lenses handled after washing with water, soap and water, or soap and water followed by towel drying were higher than the median CFU for lenses handled after no hand washing. The median CFU for lenses handled after soap and water washing followed by an alcohol wipe was not different from the no washing group. The majority of the contaminants were identified as Staphylococcus epidermidis. These results show that ordinary hand washing alone does not decrease, and may even increase, the amount of contaminants transferred from the hands to a hydrogel lens. Use of an alcoholic wipe after hand washing reverses this effect. Hand washing is still recommended in contact lens hygiene for removal of more pathogenic contaminants.  相似文献   

20.
Photorefractive keratectomy (PRK) is capable of changing the refractive power of the human cornea. Retinoscopy is an objective method of measuring the refractive power of the eye. The authors performed PRK in 28 myopic eyes with the Aesculap Meditec MEL 60 ArF excimer laser. During a prospective study, the subjective and objective refractive power of the eyes were assessed and compared 6 months after PRK. The average preoperative refractive error was: -5.11 +/- 2.51 D and -5.08 +/- 2.20 D on the right side (n = 16) and on the left side (n = 12), respectively. In order to obtain the best corrected visual acuity 6 months after PRK, the right and left eyes needed an average of -0.09 +/- 0.26 D and -0.33 +/- 0.64 D postoperative correction, respectively. The postoperative refractive change could be verified with the retinoscopy at +/-0.5 D accuracy. The authors describe a double refractive corneal ring after PRK, which may disturb retinoscopy. The post-PRK refractive change can be verified by retinoscopy. Postoperative funduscopy, fundus photography and possible future retinal procedures were not disturbed by the double corneal refractive rings in myopic eyes.  相似文献   

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