Infectious keratitis after photorefractive keratectomy

Infectious Keratitis After Keratorefractive Surgery: Update and Review of the Literature

OBJECTIVES

To summarize the clinical manifestations, microbiological profile, treatment, and prognosis of corneal infections after different keratorefractive surgery.

METHODS

To obtain relevant studies, English-language databases, including PubMed, Ovid Embase, Web of Science, and CLNAHL, were searched from January 1979 to March 2022. The fundamentals of the literature, clinical characteristics, pathogens, and treatments were retrieved for each included article.

RESULTS

Eighty-four studies involving 306 infectious eyes were included in this review. Risk factors of potential infection included a history of blepharitis, contact lens usage, and contaminated surgical instruments. The mean onset time was 22.9±38.7 days (range: 1 day to 3 years). The most common organism isolated from infectious keratitis after keratorefractive surgery were Staphylococcus aureus , followed by Mycobacterium and coagulase-negative Staphylococcus . Most of the infections after refractive procedures were sensitive to medical treatment alone, and the ultimate best-corrected visual acuity after medical treatment was as follows: 20/20 or better in 82 cases (37.0%), 20/40 or better in 170 cases (76.5%), and worse than 20/40 in 52 cases (23.5%). Surgical interventions including flap lift, flap amputation, ring removal, and keratoplasty were performed in 120 eyes (44.5%).

CONCLUSIONS

Most infections after keratorefractive surgery occur within a week, whereas more than half of the cases after laser-assisted in situ keratomileusis happen after about a month. Gram-positive cocci and mycobacterium are the most common isolates. Infections after LASIK, intracorneal ring (ICR) implantation, and small incision lenticule extraction, which primarily occur between the cornea layers, require irrigation of the tunnels or pocket with antibiotics.

Post photorefractive keratectomy (PRK) infectious keratitis; six-year experience of a tertiary eye hospital

BACKGROUND/OBJECTIVES

As an essential development in the new century, surface ablation procedures have attracted increasing attention. There exists a concern regarding the risk of infectious keratitis. Hence, we aimed to investigate the rate and predisposing factors of infectious keratitis after photorefractive keratectomy (PRK).

SUBJECTS/METHODS

This retrospective study was designed in two phases. First, the rate of post-PRK keratitis of Farabi Eye Hospital was investigated. In other words, the targeted population was the patients who developed keratitis after performing procedure at Farabi Eye Hospital. In the second phase, all the patients with the diagnosis of post-PRK keratitis were studied regardless of the centre where surgery was performed. Patients with the diagnosis of infectious keratitis between 2014 and 2020 were enrolled and following information was analyzed: demographics, presentation time after surgery, perioperative medications, culture results, risk factors, medical treatment, complications, and final visual acuity.

RESULTS

The total number of PRK procedures in our centre was 24,986 (13,253 patients), in which 6 eyes of 5 patients developed keratitis. Beside these 5 patients, 24 referred patients (24 eyes) from the other centres were enrolled. Finally, a total number of 29 patients (30 eyes) were included. Our analysis revealed that manipulation of contact lens, dry eye, and blepharitis were the essential predisposing factors for keratitis development.

CONCLUSION

The overall post-PRK keratitis occurrence rate of our study was 0.02%. Our observation highlighted the importance of preoperative examination and treatment of the lids and dry eye disease.

A Case Report of Gemella haemolysans Keratitis After Refractive Surgery

Purpose

Systematic review of Gemella haemolysans infection associated with ophthalmology, and to summarize the clinical characteristics of Gemellahaemolysans keratitis after refractive surgery.

Methods

Case report and literature review.

Results

We report an 18-year-old man who developed corneal infection after Trans-PRK, and the culture results of lesion specimens confirmed G. haemolysans keratitis. He was treated with fortified topical antibiotics, and clinical improvement was noted shortly after treatment. Resolution of keratitis was achieved at 1 month. Then, a systematic review of the reported cases of ocular G. haemolysans infection was conducted. We summarized clinical manifestations of G. haemolysans infection in cornea.

Conclusion

We reported a case of G. haemolysans keratitis infection after refractive surgery, and reviewed the literature of ocular G. haemolysans infection.

Correlation of Staphylococcus Epidermidis Phenotype and Its Corneal Virulence

PURPOSE

S. epidermidis is an ocular pathogen and a leading cause of keratitis. It produces hemolysins and at least 3 proteases. The purpose of the present study is to compare the secretion of hemolysins and proteases between 28 ocular isolates and one non-ocular strain and to determine their relationship to ocular virulence in selected strains using a rabbit model of infection.

MATERIALS AND METHODS

Culture supernatants were compared for protease production and hemolysis. Selected strains were injected into rabbit corneas and their virulence and pathology recorded. The major protease activity in a virulent strain was identified and the gene was cloned and expressed as a recombinant protein. The corneal toxicity of this protease was determined. Antibodies to the native protease were generated and tested for neutralizing activity in vivo and in vitro. The corneal pathology of the S. epidermidis protease was compared to the pathology of S. aureus V8 protease.

RESULTS

Strains that exhibited the least protease activity in vitro caused significantly less ocular pathology in vivo (p ≤ 0.003). Strains that were hemolytic and secreted a major protease had numerically higher SLE scores. This protease was identified as the serine protease Esp. The recombinant Esp protease caused extensive pathology when injected into the corneal stroma (7.62 ± 0.33). Antibody generated against native Esp did not neutralize the activity of the protease in vivo or in vitro. The antibody reacted with Esp proteases secreted by other S. epidermidis strains. S. epidermidis Esp protease and its homologue in S. aureus caused similar ocular pathology when injected in the rabbit corneal stroma.

CONCLUSION

Hemolysins and proteases seem to be important in corneal pathology caused by S. epidermidis infections. The Esp protease mediates significant corneal damage. S. epidermidis Esp and S. aureus V8 protease caused similar and extensive edema in rabbit corneas.

Decreased expression of femXAB genes and fnbp mediated biofilm pathways in OS-MRSA clinical isolates

Methicillin-Resistant Staphylococcus aureus (MRSA) is a significant threat to human health. Additionally, biofilm forming bacteria becomes more tolerant to antibiotics and act as bacterial reservoir leading to chronic infection. In this study, we characterised the antibiotic susceptibility, biofilm production and sequence types (ST) of 74 randomly selected clinical isolates of S. aureus causing ocular infections. Antibiotic susceptibility revealed 74% of the isolates as resistant against one or two antibiotics, followed by 16% multidrug-resistant isolates (MDR), and 10% sensitive. The isolates were characterized as MRSA (n = 15), Methicillin-sensitive S. aureus (MSSA, n = 48) and oxacillin susceptible mecA positive S. aureus (OS-MRSA, n = 11) based on oxacillin susceptibility, mecA gene PCR and PBP2a agglutination test. All OS-MRSA would have been misclassified as MSSA on the basis of susceptibility test. Therefore, both phenotypic and genotypic tests should be included to prevent strain misrepresentation. In addition, in-depth studies for understanding the emerging OS-MRSA phenotype is required. The role of fem XAB gene family has been earlier reported in OS-MRSA phenotype. Sequence analysis of the fem XAB genes revealed mutations in fem × (K3R, H11N, N18H and I51V) and fem B (L410F) genes. The fem XAB genes were also found down-regulated in OS-MRSA isolates in comparison to MRSA. In OS-MRSA isolates, biofilm formation is regulated by fibronectin binding proteins A & B. Molecular typing of the isolates revealed genetic diversity. All the isolates produced biofilm, however, MRSA isolates with strong biofilm phenotype represent a worrisome situation and may even result in treatment failure.

Refractive surgery in the HIV-positive U.S. Military Natural History Study Cohort: complications and risk factors

PURPOSE

This study sought to assess the frequency of refractive surgery complications in HIV+ individuals and related risk factors.

SETTINGS

Multiple centers in the United States.

DESIGN

Prospective observational cohort study.

METHODS

The U.S. Military HIV Natural History Study is a prospective observational cohort study of HIV+ service members and beneficiaries. Participants were selected who had Current Procedural Terminology codes for laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), and other refractive surgeries. The frequency of complications was determined using International Classification of Diseases-9 codes. Covariates included age, sex, antiretroviral therapy, time since HIV diagnosis, history of AIDS, and CD4 (T lymphocytes) count and viral load. Statistical analysis was completed using univariate (χ2 and Wilcoxon-Mann-Whitney tests) and multivariate analyses.

RESULTS

Seventy-nine of 2073 participants had refractive surgery. Fifty-three patients underwent PRK, 23 LASIK, 2 radial keratotomy (RK), and 1 astigmatic correction. Complications occurred in 6 (7.6%) of 79 participants, including 5 patients who underwent PRK and 1 after RK, occurring between 8 and 217 days after surgery. Five ulcers and 1 unspecified keratitis were noted. In the univariate analysis, type of surgery (P = .02) and history of AIDS (P = .02) were risk factors for complications. In logistic regression analysis, no variables were found to be risk factors for complications.

CONCLUSION

Complications were infrequent among HIV+ participants after refractive surgery. Point estimates suggest that PRK might have more complications than LASIK and that advanced HIV, reflected by previous AIDS, might be associated with an increased risk for complications. Further study will be required to confirm these findings.

Nasal and conjunctival screening prior to refractive surgery: an observational and cross-sectional study

OBJECTIVES

To investigate bacterial flora of clinically healthy conjunctiva and nasal cavity among patients prior to refractive surgery, as well as the characteristics of patients with methicillin-resistant Staphylococcus aureus (MRSA) colonisation.

DESIGN

Observational and cross-sectional study.

SETTING

A single-centre study in Japan.

PARTICIPANTS

120 consecutive patients pre-refractive surgery.

PRIMARY AND SECONDARY OUTCOME MEASURES METHODS

Samples were obtained from the right conjunctival sac and the nasal cavity of 120 consecutive patients prior to refractive surgery and were then measured for the levels of the minimum inhibitory concentration (MIC) of antibiotics. Patients were interviewed regarding their occupation, family living situation and any personal history of atopic dermatitis, asthma, smoking or contact lens wear.

RESULTS

Propionibacterium acnes (P. acnes) (32.5%) and Staphylococcus epidermidis (4.2%) were detected from the conjunctival sac. S. epidermidis was the most commonly isolated (68.3%) in the nasal cavity. Of the 30 patients (25.0%) with colonisation by S. aureus, 2 patients, both of whom were healthcare workers with atopic dermatitis, were found to be positive for MRSA in the nasal cavity. A history of contact lens wear, asthma or smoking, as well as patient gender and age, was not associated with MRSA colonisation.

CONCLUSIONS

There were only 2 patients who were colonised with MRSA, both of whom were healthcare workers with atopic dermatitis. P. acnes was predominantly found in the conjunctival sac. Further study is needed to investigate the involvement between nasal and conjunctival flora, and risk factors for infectious complications.

A retrospective analysis of the postoperative use of loteprednol etabonate gel 0.5% following laser-assisted in situ keratomileusis or photorefractive keratectomy surgery

BACKGROUND

While loteprednol etabonate ophthalmic gel 0.5% (LE gel) is approved for treatment of postoperative ocular inflammation and pain, there have been no reported studies in patients undergoing laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK).

METHODS

This was a retrospective chart review conducted at five refractive surgical centers in the USA. Data were collected from primary LASIK or PRK surgery cases in which LE gel was used postoperatively as the clinician's routine standard of care and in which patients were followed-up for up to 6 months. Data extracted from charts included patient demographics, surgical details, LE gel dosing regimen, pre- and postsurgical refractive characteristics, intraocular pressure (IOP) measurements, and visual acuity. Primary outcomes included postoperative IOP elevations, adverse events, and early discontinuations.

RESULTS

Data were collected on 189 LASIK eyes (96 patients) and 209 PRK eyes (108 patients). Mean (standard deviation [SD]) years of age at surgery was 36.0 (11.7) and 33.9 (11.3) in LASIK and PRK patients. LE gel was prescribed most often four times daily during the first postoperative week, regardless of procedure; the most common treatment duration was 7-14 days in LASIK and ≥30 days in PRK patients. No unusual corneal findings or healing abnormalities were reported. Mean postoperative uncorrected distance visual acuity was 20/24 in LASIK and 20/30 in PRK eyes. Mild/trace corneal haze was reported in 20% of PRK patients; two PRK patients with moderate/severe corneal haze were switched to another corticosteroid. Mean postoperative IOP did not increase over time in either LASIK or PRK eyes (P≥0.331); clinically significant elevations from baseline in IOP (≥10 mmHg) were noted in only three eyes of two PRK patients.

CONCLUSION

LE gel appears to have a high level of safety and tolerability when used for the management of postoperative pain and inflammation following LASIK and PRK surgery.

[Purulent corneal ulcers: etiology, pathogenesis, classification]

Advanced purulent corneal ulcer, as well as abscess, is a serious vision-threatening condition notable for its fulminant course and possible loss of the eye due to endophthalmitis. Its leading causes, pathogenesis, and classifications are described and analyzed in this paper.

Incidence of corneal infections after laser in situ keratomileusis and surface ablation when moxifloxacin and tobramycin are used as postoperative treatment

PURPOSE

To assess the incidence, culture results, and visual outcomes of infectious keratitis after laser in situ keratomileusis (LASIK) and surface ablation when topical moxifloxacin was added to postoperative prophylaxis with tobramycin.

SETTING

Clínica Baviera, Instituto Oftalmológico Europeo, Bilbao, Spain.

DESIGN

Retrospective case series review.

METHODS

The medical records of 55 255 patients (108 014 eyes) who had LASIK and surface ablation were reviewed to identify cases of infectious keratitis. The incidence, risk factors, clinical course, days to diagnosis, treatment, and final visual outcomes were recorded. These data were compared with previously published data of 221 437 eyes that received postoperative tobramycin alone.

RESULTS

Post-LASIK infectious keratitis was diagnosed in 10 eyes (9 patients) and post-surface ablation infectious keratitis in 11 eyes (10 patients). The onset of infection was early in 40.00% of cases after LASIK and in 36.36% after surface ablation. Cultures were positive in 2 cases after surface ablation. Immediate flap lifting and irrigation with antibiotics were performed in all eyes after LASIK. The final corrected distance visual acuity was 20/20 or better in 7 cases after LASIK (70.00%) and 7 cases after surface ablation (63.64%) and 20/40 or better in all cases after LASIK or surface ablation.

CONCLUSIONS

The incidence of infectious keratitis decreased from 0.025% to 0.011% (P < .001) per procedure after LASIK and from 0.200% to 0.066% (P < .001) after surface ablation. Infectious keratitis was less frequent after LASIK than after surface ablation. The frequency of infection, mainly early-onset infection, was lower when the postoperative treatment was tobramycin and moxifloxacin rather than tobramycin alone.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Current knowledge about and recommendations for ocular methicillin-resistant Staphylococcus aureus

Staphylococcus aureus is the most important and common pathogen that infects patients following cataract surgery, laser in situ keratomileusis, and photorefractive keratectomy. It is reported to be the second most common pathogen causing bacterial keratitis around the world. Of special concern are increasing reports of postoperative methicillin-resistant S aureus (MRSA) infection. For example, MRSA wound infections have been reported with clear corneal phacoemulsification wounds, penetrating keratoplasty, lamellar keratoplasty, and following ex vivo epithelial transplantation associated with amniotic membrane grafts. These and other data suggest that MRSA has become increasingly prevalent worldwide. In this article, we review the current medical literature and describe the current challenge of ocular MRSA infections. Recommendations are made based on an evidence-based review to identify, treat, and possibly reduce the overall problem of this organism.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Ocular microbiology trends in Edmonton, Alberta: a 10-year review

OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as an increasingly common cause of nosocomial infections since the 1980s.(1) Reports of ocular infections due to MRSA are composed primarily of case reports. But a recent report from the United States suggests that ocular infections due to MRSA are about to become more common than methicillin-sensitive S. aureus (MSSA).(2) However, this observation is not consistent with anecdotal experience at the University of Alberta. The purpose of this study is to evaluate the ocular microbiology trends in a tertiary care eye center in Canada.

METHODS

Cross-sectional study using a computer search of the DynaLIFE(DX) Diagnostic Laboratory Services database for all positive ocular microbiology cultures and in vitro antibiotic susceptibilities performed in the Edmonton area.

RESULTS

Over a 10-year period, between 2000 and 2010, 6.4% of S. aureus isolates were MRSA; there were 2030 MSSA and 129 MRSA isolates, including 46 MSSA and 4 MRSA isolates from deep eye cultures. The prevalence of MRSA over the total number of S. aureus isolates, regardless of specimen source, steadily increased in the 10-year period, from 0.5% in 2002 to 12.6% in 2010. Gram-positive cocci were the most common organisms to cause ocular infections (82.6%). In vitro susceptibility of ocular MSSA and MRSA samples demonstrated 100% sensitivity to vancomycin.

CONCLUSIONS

The prevalence of MRSA ocular infections, although still uncommon, appears to be increasing in Edmonton, Alberta.

Staphylococcus aureus ocular infection: methicillin-resistance, clinical features, and antibiotic susceptibilities

Background

Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. The study aimed to determine the prevalence of ocular infections caused by MRSA and to identify the clinical characteristics and antibiotic susceptibility of ocular MRSA infections by comparing those of ocular methicillin-sensitive S. aureus (MSSA) infections.

Methodology/Principal Findings

The medical records of the patients (n = 519) with culture-proven S. aureus ocular infections seen between January 1, 1999 and December 31, 2008 in Chang Gung Memorial Hospital were retrospectively reviewed. Two hundred and seventy-four patients with MRSA and 245 with MSSA ocular infections were identified. The average rate of MRSA in S. aureus infections was 52.8% and the trend was stable over the ten years (P value for trend  = 0.228). MRSA ocular infections were significantly more common among the patients with healthcare exposure (P = 0.024), but 66.1% (181/274) patients with MRSA ocular infections had no healthcare exposure. The most common clinical presentation for both MRSA and MSSA ocular infections was keratitis; MRSA and MSSA caused a similar disease spectrum except for lid infections. MRSA was significantly more resistant than MSSA to clindamycin, erythromycin and sulfamethoxazole/trimethoprim (all P<0.001).

Conclusions/significance

We demonstrated a paralleled trend of ocular MRSA infection in a highly prevalent MRSA country by hospital-based survey. Except for lid disorder, MRSA shared similar spectrum of ocular pathology with MSSA. Since S. aureus is a common ocular pathogen, our results raise clinician’s attention to the existence of highly prevalent MRSA.

Bilateral methicillin-resistant Staphylococcus aureus keratitis following hyperopic photorefractive surgery

To report clinical manifestations of a female patient with bilateral bacterial keratitis following photorefractive keratectomy (PRK). Bilateral PRK was performed for moderate hyperopia. Bandage contact lenses were fitted at the conclusion of the surgery. Bilateral infectious keratitis with hypopion was diagnosed within 4 days after surgery. Smear and culture were obtained and showed the presence of methicillin-resistant Staphylococcus aureus (MRSA). The patient was treated with systemic prednisone and topical antibiotics (vancomycin, tobramycin and netylmicin) and betamethasone. After 1 month corneal leukoma was still present and remained unchanged during the following 7 months. Infectious keratitis is a rare complication of PRK that appears early in the postoperative period. MRSA keratitis may determine long-term visual impairment despite prompt therapeutic intervention.

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.

Microbial keratitis after corneal laser refractive surgery

Corneal laser refractive surgery is increasingly being performed on patients with the aim of improving unaided vision. Most candidates for surgery have excellent spectacle- or contact lens-corrected vision. Although microbial keratitis following refractive surgery is a rare complication, and usually has a good visual outcome, it can be sight-threatening. The spectrum of pathogens differs to other causes of microbial keratitis, such as contact lens-associated keratitis, and a different management approach is required. Postoperatively, patients are prescribed topical steroids and broad-spectrum topical antibiotics, typically fluoroquinolones. These do not cover unusual organisms, such as fungi, Nocardia, Acanthamoeba and some atypical mycobacteria. In post-laser-assisted in situ keratomileusis microbial keratitis, the lamellar flap should be lifted to acquire samples for specific microbiological examination, including these atypical organisms. Confocal microscopy is a noninvasive test that provides morphological information, and is operator dependent, but may assist in the rapid diagnosis of fungal, Acanthamoeba or Norcardia keratitis. PCR is not in widespread use, but has high sensitivity and specificity, and may facilitate early diagnosis and specific treatment of the causative organism, which is critical in obtaining the best clinical outcome.

Microbial keratitis trends following refractive surgery: results of the ASCRS infectious keratitis survey and comparisons with prior ASCRS surveys of infectious keratitis following keratorefractive procedures

In 2008, the American Society of Cataract and Refractive Surgery (ASCRS) surveyed its 9121 United States and international members to evaluate the changing trends and incidence, culture results, treatment, and visual outcomes of infectious keratitis following keratorefractive procedures worldwide. This paper presents and analyzes the results with comparisons to the data in surveys conducted in 2001 and 2004. Nineteen infections were reported by 14 surgeons who had performed an estimated 20,941 keratorefractive procedures, an incidence of 1 infection in every 1102 procedures. Sixteen cases presented in the first postoperative week, 1 case during the second week, 1 case between the second and fourth weeks, and 1 case at 1 month or later. The 16 cases that presented in the first week were diagnosed at initial presentation. The most common organism cultured was methicillin-resistant Staphylococcus aureus (MRSA). Microbial keratitis following refractive surgery is an increasingly recognized sight-threatening complication.

Infectious keratitis in 18,651 laser surface ablation procedures

PURPOSE

To evaluate the incidence, culture results, risk factors, treatment strategies, and visual outcomes of infectious keratitis after surface ablation.

SETTING

Multicenter study in Spain.

DESIGN

Case series.

METHODS

The medical records of patients who had surface ablation between January 2003 and December 2009 were reviewed to identify cases of infectious keratitis. The incidence, risk factors, clinical course, days to diagnosis, medical and surgical treatment, and visual outcome were recorded. Main outcome measures were incidence of infectious keratitis after surface ablation, culture results, response to treatment, and visual outcomes.

RESULTS

The study reviewed the records of 9794 patients (18,651 eyes). Infectious keratitis after surface ablation was diagnosed in 39 eyes of 38 patients. The onset of infection was early (within 7 days after surgery) in 28 cases (71.79%). Cultures were positive in 13 of 27 cases in which samples were taken. The most frequently isolated microorganism was Staphylococcus species (9 cases). The final corrected distance visual acuity (CDVA) was 20/20 or better in 23 cases (58.97%), 20/40 or better in 36 cases (92.30%), and worse than 20/40 in 3 cases (7.69%).

CONCLUSIONS

The incidence of infectious keratitis after surface ablation was 0.20%. Infectious keratitis is a potentially vision-threatening complication. Prompt and aggressive management with an intensive regimen of fortified antibiotic agents is strongly recommended. Proper management can preserve useful vision in most cases.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Surface ablation techniques

The ongoing quest for a safe, simple, effective, minimally invasive, and stable refractive surgical procedure to correct refractive errors has stimulated the development of surface ablation techniques and laser in situ keratomileusis. In this review, we describe the history, patient assessment, techniques, outcomes, and complications of surface ablation (photorefractive keratectomy, laser-assisted sub-epithelial keratectomy, epithelial laser-assisted in situ keratomileusis) and compare the results of various surface techniques. Surface ablation procedures will continue to evolve, with potential improvements in outcomes accompanying future sophisticated ablation profiles and laser technology.

Moxifloxacin and cholesterol combined treatment of pneumococcal keratitis

PURPOSE

Compare the efficacy of treatment of pneumococcal keratitis with cholesterol, moxifloxacin, or a mixture of the two (moxifloxacin/cholesterol).

MATERIALS AND METHODS

New Zealand white rabbits were injected intrastromally with 10(6) colony-forming units (CFU) of a clinical keratitis strain of Streptococcus pneumoniae. Eyes were examined before and after treatment of topical drops every 2 hr from 25 to 47 hr post-infection (PI). Corneas were harvested to quantitate bacterial CFU, and myeloperoxidase (MPO) activity was measured at 48 hr PI. Eyes were extracted for histology. Minimal inhibitory concentrations (MICs) were determined for each compound.

RESULTS

Eyes treated with moxifloxacin/cholesterol had a significantly lower mean slit lamp examination (SLE) score than eyes treated with phosphate-buffered saline (PBS), moxifloxacin alone, or cholesterol alone (P ≤ 0.02). A significantly lower log(10) CFU was recovered from corneas treated with moxifloxacin/cholesterol and moxifloxacin alone as compared to corneas of eyes treated with PBS or cholesterol alone (P < 0.01). At 48 hr PI, significantly lower MPO activity was quantitated from eyes treated with moxifloxacin/cholesterol as compared to eyes treated with cholesterol or moxifloxacin alone (P ≤ 0.046). Eyes treated with moxifloxacin/cholesterol had fewer immune cells and less corneal destruction than eyes from all other treatment groups. The MIC for moxifloxacin alone was 0.125 μg/mL, and cholesterol alone was unable to inhibit growth at any of the concentrations tested. The MIC for moxifloxacin when combined with 1% cholesterol was 0.0625 μg/mL.

CONCLUSIONS

Treatment with a mixture of moxifloxacin and cholesterol significantly lowers the severity of infection caused by pneumococcal keratitis as compared to treatment with moxifloxacin alone, cholesterol alone, or PBS. This treatment mixture eradicates the bacteria in the cornea, unlike treatment with PBS or cholesterol alone. Using cholesterol with moxifloxacin as a treatment for bacterial keratitis could help lower the clinical severity of the infection.

Efficacy and safety of short-duration topical treatment with azithromycin oil-based eyedrops in an experimental model of corneal refractive surgery

PURPOSE

To assess the tolerance and side effects of azithromycin eyedrops at the ocular surface after corneal refractive surgery in an experimental animal model.

METHODS

The effect of azithromycin eyedrops was evaluated in hen corneas that underwent laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) surgery in 1 eye, using the fellow eye (not manipulated) as a control. Animals were treated bid 3 days prior to surgery and 3 days after surgery with T1225 1.5% azithromycin eyedrops or saline eyedrops (balanced salt solution), or were left untreated as a control. Clinical course and cell biology (apoptosis, proliferation, and differentiation) measurements were assessed.

RESULTS

Infections were present in the following proportions of corneas operated on by LASIK: 0% treated with azithromycin, 60% treated with BSS, and 30% untreated. No corneal abscess or keratitis were present in any PRK or unmanipulated corneas. Conjunctival edema and redness were less prevalent in LASIK-operated eyes treated with azithromycin than in BSS-treated or untreated eyes and were not observed in any PRK or unmanipulated corneas. In PRK-operated eyes treated with azithromycin, a decrease was observed in the apoptosis and an increase in the stromal proliferation. There were no differences in these parameters for LASIK and unmanipulated eyes.

CONCLUSIONS

Topical administration of T1225 oil-based azithromycin eyedrops was well tolerated in both unmanipulated hen corneas and those treated with corneal refractive surgery (PRK and LASIK). T1225 demonstrated a potent antibiotic effect after LASIK treatment.

The effectiveness of an improved combination therapy for experimental Staphylococcus aureus keratitis

INTRODUCTION

antibiotic and steroid combination therapies, such as tobramycin with dexamethasone, are often used in ophthalmology to treat or prevent infection and inflammation. The purpose of this study was to use a model of Staphylococcus aureus keratitis to quantify and compare the effectiveness of a standard tobramycin and dexamethasone combined therapy, with each drug individually, and with a new formulation of the two drugs in a xanthan gum vehicle.

METHODS

rabbit corneas were intrastromally injected with a methicillin-sensitive S. aureus (MSSA) or a methicillin-resistant S. aureus (MRSA) strain. Rabbit eyes were treated every hour from 10 to 15 hours postinfection (PI) with 0.1% dexamethasone, 0.3% tobramycin, 0.3% tobramycin with 0.1% dexamethasone, or 0.3% tobramycin with 0.05% dexamethasone in a xanthan gum vehicle (ST). Slit lamp examinations (SLE) were performed on infected eyes and pathology scored at 15 hours PI. At 16 hours PI, colony forming units (CFUs) per cornea were quantified.

RESULTS

the CFUs in eyes treated with dexamethasone alone were similar to untreated control eyes for MSSA or MRSA infections. All other treatment groups had significantly less CFUs per cornea than untreated eyes. The eyes treated with the ST formulation had significantly fewer CFUs per cornea than all other treatment groups when infected with MSSA or MRSA. The SLE scores of MSSA or MRSA infected eyes treated with tobramycin alone were similar to untreated control eyes. All other treatment groups had significantly lower SLE scores than untreated controls eyes, but were not significantly different from each other.

CONCLUSION

the results of this study demonstrated that the tobramycin and dexamethasone combination therapy with a xanthan gum vehicle has an improved bactericidal effectiveness compared to the commercially available formulation, and maintains a similar anti-inflammatory effect while containing half the amount of steroid.

The inhibitory effect of vancomycin ointment on the manifestation of MRSA keratitis in rabbits

The purpose of this study was to investigate an experimental model of methicillin-resistant Staphylococcus aureus (MRSA) keratitis, and to evaluate the inhibitory effect of vancomycin ointment on the manifestation of keratitis in this model. For the development of the MRSA keratitis model, 16 rabbits received 0.3-ml intrastromal injections of 1 x 10(7) colony forming units/ml MRSA inoculated to each of their corneas. After the MRSA inoculation, the rabbits were examined for a period of 14 days. Vehicle only was applied to each left eye for 2 days as an experimental control. Prototype vancomycin ointments, at concentrations of 0.03%, 0.1%, 0.3%, and 1.0%, were applied to each right eye for 2 days. The treatment commenced immediately after the MRSA inoculation and was administered five times a day at 2-h intervals. Four rabbits were used for each vancomycin ointment concentration. Anterior segments were examined daily, and the minimum inhibitory concentration of vancomycin (percentage in the ointment) for treating MRSA keratitis was determined on day 2. On day 14, no recurrences of infection were observed in the eyes that had not exhibited keratitis on day 2. Forty-eight hours post-inoculation, all left eyes demonstrated severe conjunctivitis, stromal infiltrates at injection sites, and fibroid reactions in the anterior chamber. MRSA keratitis was completely inhibited by 0.3% and 1.0% vancomycin ointments. Although the 0.1% ointment generally could prevent keratitis, punctate infiltrates were found in some eyes. Numerous infiltrates were found in eyes treated with 0.03% ointment. In conclusion, the present study substantiates the view that vancomycin ointment has a potent inhibitory effect upon the manifestations of MRSA keratitis, and indicates that a 0.3% concentration is necessary for effective treatment.

Outbreak of Nocardia keratitis after photorefractive keratectomy: clinical, microbiological, histopathological, and confocal scan study

Nocardia keratitis occurred in 4 eyes of 3 patients (2 women and 1 man) who had photorefractive keratectomy (PRK) by the same surgeon at the same center. Two eyes of the first 2 patients required lamellar keratectomy to debulk the involved stroma and obtain specimens for microbiological and histopathological evaluation. Light microscopic examination disclosed gram-positive and acid-fast filaments of Nocardia that were confirmed by the microbiological results. Diagnosis of Nocardia keratitis in the third case was not as challenging as in the first 2 cases because of a high index of suspicion. Confocal scans of all cases disclosed hyperreflective and slender, fibril-like structures in the corneal stroma. All eyes responded favorably to topical amikacin and the infection resolved without recurrence. The most probable cause of the outbreak was inadequate attention to sterility during surgery.

Rate of bacterial eradication by ophthalmic solutions of fourth-generation fluoroquinolones

INTRODUCTION

Antibacterial activity of ophthalmic fourth-generation fluoroquinolones has traditionally been evaluated by comparing only their active ingredients, gatifloxacin and moxifloxacin. However, ophthalmic formulations of fourth-generation fluoroquinolones differ in terms of the inclusion of preservatives. While gatifloxacin ophthalmic solution 0.3% (Zymar; Allergan, Inc., Irvine, CA, USA) contains 0.005% benzalkonium chloride (BAK), moxifloxacin ophthalmic solution 0.5% (Vigamox; Alcon Laboratories, Inc., Fort Worth, TX, USA) is preservative-free. Recent studies have demonstrated that the presence of BAK dramatically affects the antibacterial activity of the ophthalmic formulation of gatifloxacin. This study was designed to compare the kill rates of ophthalmic solutions of fourth-generation fluoroquinolones against isolates of common ocular bacterial pathogens.

METHODS

Approximately 5.6 log(10) colony-forming units (CFU)/mL of Haemophilus influenzae (n=1), Streptococcus pneumoniae (n=1), Staphylococcus aureus (n=2), methicillin-resistant Staphylococcus aureus (MRSA) (n=4), methicillinresistant Staphylococcus epidermidis (MRSE) (n=4), and fluoroquinolone-resistant S. epidermidis (n=1) were incubated with ophthalmic solutions of either gatifloxacin or moxifloxacin. Viable bacteria were quantified at specific time points up to 60 minutes.

RESULTS

Gatifloxacin 0.3% completely eradicated H. influenzae and Strep. pneumoniae in 5 minutes, one of two S. aureus isolates in 15 minutes, and the other S. aureus isolate in 60 minutes. Gatifloxacin 0.3% completely killed all MRSA, MRSE, and fluoroquinolone-resistant S. epidermidis isolates in 15 minutes. Moxifloxacin 0.5% completely eradicated Strep. pneumoniae and one of four MRSA isolates in 60 minutes. All other isolates incubated with moxifloxacin 0.5% retained viable bacteria ranging from 1.8 to 4.4 log(10) CFU/mL.

CONCLUSIONS

The ophthalmic solution of gatifloxacin 0.3% eradicated bacteria that frequently cause postoperative ocular infections substantially faster than did the ophthalmic solution of moxifloxacin 0.5%.

Increasing prevalence of methicillin resistance in serious ocular infections caused by Staphylococcus aureus in the United States: 2000 to 2005

PURPOSE

To report the nationwide prevalence of methicillin resistance in serious ocular infections involving Staphylococcus aureus and profile in vitro antimicrobial susceptibility of S aureus from ocular isolates over time.

SETTING

Mount Sinai School of Medicine, New York, New York, USA.

METHODS

Data on S aureus submitted to The Surveillance Network (TSN) by more than 200 laboratories in the United States from January 2000 to December 2005 were reviewed. The prevalence of methicillin resistance in S aureus ocular infections and in vitro susceptibility to antibiotic agents commonly used to treat or prevent ocular infections were determined.

RESULTS

The proportion of S aureus infections culture-positive for methicillin-resistant S aureus (MRSA) increased from 29.5% in 2000 to 41.6% in 2005. The MRSA ocular isolates were multidrug resistant; that is, in vitro resistance to 3 antibiotic agents or more, including all fluoroquinolones tested.

CONCLUSIONS

Multidrug-resistant MRSA is increasing in serious ocular infections. Based on the rate of increase in the TSN database, MRSA cultures from serious ocular infections could be more common than methicillin-susceptible S aureus within 2 to 3 years. Large-scale national surveillance programs are needed to monitor in vitro antimicrobial resistance trends in ocular isolates.

Microbiologic study of soft contact lenses after laser subepithelial keratectomy for myopia

PURPOSE

To evaluate the extent and agents of bacterial contamination of bandage disposable soft contact lenses after laser subepithelial keratectomy (LASEK) and to correlate the findings with clinical data.

METHODS

Disposable soft contact lenses were collected from 52 eyes of 26 consecutive patients treated with LASEK for myopia. The patients were treated with a fixed combination of tobramycin and diclofenac until epithelial closure. The lenses were removed on the fourth or fifth postoperative day with sterile forceps and immediately placed in sterile tubes containing culture media brain-heart infusion broth. The lenses were evaluated for microbial colonization.

RESULTS

Of the 52 contact lenses analyzed, six (11.5%) had positive cultures. However, no clinical finding of infection was noted. Isolated microorganisms were coagulase-negative staphylococci (two lenses), Stenotrophomonas maltophilia (two lenses), Acinetobacter species (one lens), and Aeromonas hydrophila (one lens). Except for one case, the microorganisms were sensitive to the administered antibiotic.

CONCLUSIONS

The risk of infectious keratitis after LASEK seems to be low. Except for staphylococci, the isolated microorganisms have not been previously reported to colonize the ocular surface or cause keratitis after refractive surgery. These findings may suggest a changing trend of potentially infectious agents after surface ablation.

Multilayer amniotic membrane transplantation for bacterial keratitis with corneal perforation after hyperopic photorefractive keratectomy

We report a case of corneal infection caused by Streptococcus pneumoniae after hyperopic photorefractive keratectomy (PRK) that produced severe corneal melting, ulceration, and multiple perforations. Treatment included antibiogram-based antibiotic topical therapy and multilayer amniotic membrane transplantation (AMT) performed to seal the perforations and restore the globe integrity. Clinical and anterior segment optical coherence tomography (Visante OCT, Carl Zeiss Meditec) examinations documented progressive integration of the amniotic membrane tissues within the cornea, stromal and epithelial healing, and recovery of a stable and regular anterior chamber. The cornea healed with an avascular leucoma; the best corrected visual acuity was reduced to 20/200. Severe pneumococcal ulcerative perforation is a potential complication of PRK. Penetrating keratoplasty, at high risk for failure in the acute settings of an infected and inflamed eye, can be delayed until the cornea is healed. Amniotic membrane transplantation may be an alternative surgical option to achieve this goal.

Effect of Fourth-Generation Fluoroquinolones on the Healing Rate of Corneal Erosions in an Animal Model

PURPOSE

To compare the rate of epithelial healing of corneal erosion in an animal model with 2 commercial formulations of fourth-generation fluoroquinolones: 0.3% gatifloxacin and 0.5% moxifloxacin.

METHODS

Corneal erosions, 6 mm in diameter, were created in 28 rabbit eyes. The rabbits were randomized to receive topical gatifloxacin, moxifloxacin, or nonpreserved saline. Drops were administered every 15 minutes for 1 hour, then hourly for 3 hours, and then 4 times daily until the erosion reepithelialized. Eyes were examined with fluorescein drops and photographed every 12 hours with a cobalt blue-filtered light. When reepithelialization was observed, the rabbits were euthanized, and their eyes were enucleated for histopathologic evaluation.

RESULTS

Reepithelialization of the corneal erosions was fastest in the saline-treated eyes (57.3 +/- 8 hours), followed by moxifloxacin (62.7 +/- 11.7 hours) and gatifloxacin (66 +/- 8.5 hours). These differences in the time to closure of the erosions among the 3 groups were not statistically significant. Although significant differences were found among the healing progression curves when all 3 groups were compared (P = 0.042), the difference between the 2 antibiotic-treated groups was not significant.

CONCLUSIONS

Only slight differences in epithelial healing rates were found between the gatifloxacin-, moxifloxacin-, and saline-treated groups, suggesting that the 2 fluoroquinolones may have an equivalent role as prophylactic treatment of trauma- or surgery-induced corneal erosions.

Prophylactic gatifloxacin therapy in prevention of bacterial keratitis in a rabbit laser in situ keratomileusis model

PURPOSE

Use the ID(50) (infectious dose to 50% of experimental animals) to quantify the most effective prophylactic dosing regimen to use with gatifloxacin 0.3% (Zymar) for the prevention of keratitis in a rabbit laser in situ keratomileusis model of Staphylococcus epidermidis infection.

SETTING

University Laboratory, University of Arizona, Tucson, Arizona, USA.

METHODS

Two groups of rabbits were compared in each of 2 experiments that were separated by 12 months. In the first experiment, rabbits receiving no postoperative antibiotic therapy (Group 1) were compared with rabbits receiving postoperative antibiotic therapy (Group 2). In the second experiment, postoperative antibiotic therapy (Group 3) was compared with preoperative and postoperative antibiotic therapy (Group 4). All antibiotic regimens used gatifloxacin 0.3%. Before antibiotic therapy began, corneal pockets were created in the right eye of each rabbit and all rabbits received balanced salt solution (BSS) only or BSS and S epidermidis inoculations in the corneal pocket. Rabbits were monitored for corneal infiltrates after surgery.

RESULTS

The ID(50) of the first, second, third, and fourth groups of rabbits was 10(2), 10(4), 10(5), and 10(7) organisms, respectively. The data showed a statistically significant difference between rabbits receiving BSS only and most rabbits receiving BSS plus inoculate at each postoperative measurement (P<.05).

CONCLUSIONS

The findings suggest that the use of both preoperative and postoperative antibiotic therapy may be most effective in preventing infection. Postoperative antibiotic therapy increased the number of S epidermidis necessary to cause infection by at least 100-fold over no antibiotic intervention. Preoperative plus postoperative antibiotic therapy increased the number of bacteria necessary to cause infection by at least 100-fold over postoperative therapy alone and by more than 10000-fold over no antibiotic intervention.

Methicillin-resistant Staphylococcus aureus infectious keratitis following refractive surgery

PURPOSE

To elucidate risk factors, clinical course, visual outcomes, and treatment of culture-proven methicillin-resistant Staphylococcus aureus (MRSA) infectious keratitis following refractive surgery.

DESIGN

Interventional case series.

METHODS

Multicenter chart review of 13 cases of MRSA keratitis following refractive surgery and literature review.

RESULTS

Thirteen eyes of 12 patients, nine of whom were either healthcare workers or exposed to a hospital surgical setting, developed MRSA keratitis following refractive surgery. All patients presented with a decrease in visual acuity and complaints of pain or irritation in the affected eye. Common signs on slit-lamp biomicroscopy were corneal epithelial defects, focal infiltrates with surrounding edema, conjunctival injection, purulent discharge, and hypopyon. All patients were diagnosed with infectious keratitis on presentation and treated with two antibiotics. All eyes were culture-positive for MRSA.

CONCLUSIONS

According to a computerized MEDLINE literature search, this is the first case series of MRSA infectious keratitis following refractive surgery, the first reports of MRSA keratitis after refractive surgery in patients with no known exposure to a healthcare facility, the first report of MRSA keratitis after a laser in situ keratomileusis (LASIK) enhancement, and the first reports of MRSA keratitis after prophylaxis with fourth-generation fluoroquinolones. MRSA keratitis is a serious and increasing complication following refractive surgery. Patients with exposure to a healthcare environment should be considered at additional risk for developing MRSA keratitis. However, in addition, surgeons should now be vigilant for community-acquired MRSA. Prompt identification with culturing and appropriate treatment of MRSA keratitis after refractive surgery is important to improve visual rehabilitation.

Bilateral methicillin-resistant Staphylococcus aureus keratitis after photorefractive keratectomy

A 52-year-old woman with a history of liver transplantation developed bilateral corneal infiltrates 1 week after uneventful photorefractive keratectomy (PRK). Cultures grew methicillin-resistant Staphylococcus aureus (MRSA), resistant to fluoroquinolone antibiotics. The infections responded to topical vancomycin and resolved bilaterally over 3 weeks. Three months postoperatively, the uncorrected visual acuity (UCVA) was 20/20 in the right eye and 20/25 in the left eye; the best spectacle-corrected visual acuity (BSCVA) was 20/20 in both eyes. During the course of treatment, the patient reported chronic intermittent prophylactic use of oral ciprofloxacin. While fluoroquinolones typically provide excellent postoperative coverage, Staphylococcus organisms have a growing antibiotic resistance to fluoroquinolones, and MRSA may become a more prevalent organism in corneal infections. Chronic subtherapeutic fluoroquinolone use can increase the mutational resistance of Staphylococcus to fluoroquinolone and methicillin. The patient's frequent hospital visits placed her at high risk for MRSA colonization. This case represents the fifth reported case of MRSA keratitis after PRK.

Bilateral Bacterial Keratitis in Three Patients Following Photorefractive Keratectomy

PURPOSE

To report clinical manifestations and the bacteriologic profiles of three patients with bilateral bacterial keratitis following photorefractive keratectomy (PRK).

METHODS

Photorefractive keratectomy was performed for mild to moderate myopia or compound myopic astigmatism. Bandage contact lenses were fitted at the conclusion of each surgery. Bilateral infectious keratitis was diagnosed within 3 days after surgery. Smear and culture were obtained in all three cases. Patients were treated with topical fortified antibiotics (cefazolin and gentamicin).

RESULTS

All patients presented with severe bilateral ocular pain, photophobia, purulent discharge, and dense corneal infiltration. Causative organisms were Staphylococcus aureus (n = 2) and Streptococcus pneumoniae (n = 1). Ulcers were controlled with aggressive medical therapy in five eyes; however, tectonic penetrating keratoplasty was required in one eye.

CONCLUSIONS

Uncontrolled blepharitis and bandage contact lens use appears to play a role in the development of bacterial keratitis after PRK. Avoidance of simultaneous bilateral surgery in patients with risk factors for bacterial keratitis, preoperative control of blepharitis, and good contact lens hygiene is suggested.

Acute systemic immune activation following conjunctival exposure to staphylococcal enterotoxin B

Conjunctival exposure to the Staphylococcus aureus superantigen staphylococcal enterotoxin B (SEB) may occur accidentally, as a result of bioterrorism, or during colonization or infection of the external eye. Using human leukocyte antigen class II transgenic mice, we show for the first time that conjunctival exposure to SEB can cause robust systemic immune activation.

Ophthalmic Manifestations of Infections Caused by the USA300 Clone of Community-Associated Methicillin-Resistant Staphylococcus aureus

PURPOSE

To report the microbiological, clinical, and pathological characteristics of community-associated methicillin-resistant Staphylococcus aureus (CAMRSA) infections of the eye and orbit.

DESIGN

Prospective case series.

PARTICIPANTS

Nine patients with CAMRSA infections of the eye and orbit were identified during a 6-month period at 2 tertiary care hospitals in San Francisco.

METHODS

Case identification was by prospective case selection and retrospective laboratory review of 549 MRSA cultures collected in the 2 hospitals. Ophthalmic microbial isolates were analyzed by pulsed-field gel electrophoresis and compared with a control CAMRSA clone (USA300). Clinical characteristics of patients infected with CAMRSA were reviewed, and all surgical specimens underwent pathological examination.

MAIN OUTCOME MEASURES

Pulsed-field gel electrophoresis banding patterns of MRSA isolates, antibiotic sensitivity profiles, patient demographics, systemic and ocular complications of infection, and posttreatment visual acuities.

RESULTS

Nine ophthalmic isolates were CAMRSA clone USA300. The infections included orbital cellulitis, endogenous endophthalmitis, panophthalmitis, lid abscesses, and septic venous thrombosis. Patients were treated with trimethoprim-sulfamethoxazole, rifampin, clindamycin, or vancomycin based on microbial sensitivity studies and severity of infection. Eight of the 9 patients had no history of hospitalization. Seven patients required hospitalization, 3 required surgery, and an additional 4 required invasive procedures. Eight patients had good visual outcomes, but 1 deteriorated to no light perception. Pathological analyses showed extensive necrosis in eyelid and orbital specimens, and disorganized atrophy bulbi in an enucleated eye.

CONCLUSION

The USA300 CAMRSA clone, which carries Panton-Valentine leukocidin genes, can cause aggressive infections of the eye and orbit in hospital-naive patients. Treatment of infections often required debridement of necrotic tissues in addition to non-beta-lactam class antibiotics. In communities where CAMRSA is prevalent, ophthalmologists should obtain microbial cultures and sensitivity studies to help guide antibiotic therapy for severe ophthalmic infections.