Outcomes and Quality of Life After Resorbable Synthetic Ventral Hernia Repair in Contaminated Fields.

INTRODUCTION: The ideal mesh type for hernia repair in a contaminated field remains controversial. Data regarding outcomes beyond 1 year and the impact on quality of life (QoL) are unknown. This study aims to evaluate the long-term surgical outcomes and patient-reported outcomes (PROs) after contaminated repair with poly-4-hydroxybutyrate (P4HB) mesh. MATERIALS METHODS: Patients undergoing a contaminated hernia repair with P4HB between 2015 and 2020 were identified. Surgical site occurrences and hernia recurrences were recorded. Long-term PROs as defined by the Abdominal Hernia-Q and Hernia-Related Quality-of-Life Survey were assessed. RESULTS: Fifty-five patients were included with a mean age of 54.5 years, a body mass index of 34 kg/m2, and a defect size of 356.9 ± 227.7 cm2. Median follow-up time was 49 months with a reoperation rate of 14.5% and a hernia recurrence rate of 7.3%. Of the 55 patients, 37 completed preoperative and postoperative PRO questionnaires. When comparing preoperative with postoperative Abdominal Hernia-Q, there was significant improvement in overall PROs (2.1 vs 3.5, P < 0.001). This improvement was maintained with no significant changes between postoperative scores over the course of 5 years. Patients with complications saw the same improvement in postoperative PRO scores as those without complications. CONCLUSIONS: Our study found a low hernia recurrence and acceptable long-term reoperation rates in patients undergoing hernia repair with P4HB mesh in a contaminated setting. We demonstrate a sustained significant improvement in QoL scores after hernia repair. These data yield insight into the long-term outcomes and QoL improvement, providing physicians further knowledge to better counsel their patients.

Increased Patient Age as a Risk Factor Following Free Flap Reconstruction after Breast Cancer: A Single Institutional Review of 2,598 Cases.

BACKGROUND: Autologous breast reconstruction (ABR) after mastectomy is increasing due to benefits over implant-based reconstruction. However, free flap reconstruction is not universally offered to patients of advanced age due to perceived increased perioperative risk. METHODS: Patients undergoing free flap breast reconstruction at our institution from 2005 to 2018 were included. Risk-adjusted logistic regression models were fit while controlling for demographic and comorbid characteristics to determine the association of age with the probability of venous thromboembolism (VTE), delayed healing, skin necrosis, surgical site infection (SSI), seroma, hematoma, hernia, and flap loss. Linear predictions from risk-adjusted logistic regression models were used to create spline curves and determine the risk of outcomes associated with age. RESULTS: A cohort of 2,598 patients underwent free flap breast reconstruction in the period examined. The median age was 51 with approximately 9% of patients being 65 or older. Increased age was associated with a greater risk of delayed healing, skin necrosis, and hematoma after surgery. There was no increased risk of medical complications such as VTE or complications such as flap loss, seroma, or SSI. CONCLUSION: A set age cutoff for patients undergoing free flap breast reconstruction does not appear warranted. There is no difference in major surgical complications such as flap loss with increasing age. However, older age does predispose patients to specific wound complications such as hematoma, skin necrosis, and delayed wound healing, which should guide preoperative counseling. Further, medical complications do not increase with advanced age. Overall, however, the safety of ABR in older patients appears uncompromised.

Preoperative Botulinum Toxin for Abdominal Wall Reconstruction in Massive Hernia Defects-A Propensity-Matched Analysis.

PURPOSE: Reconstruction of massive incisional hernias (IHs) poses a significant challenge with high rates of recurrence. Preoperative chemodenervation using botulinum toxin (BTX) injections in the abdominal wall is a technique that has been used to facilitate primary fascial closure. However, there is limited data directly comparing primary fascial closure rates and postoperative outcomes after hernia repair between patients who do and do not receive preoperative BTX injections. The objective of our study was to compare the outcomes of patients who did and did not receive BTX injections before abdominal wall reconstruction. METHODS: This is a retrospective cohort study including adult patients from 2019 to 2021 who underwent IH repair with and without preoperative BTX injections. Propensity score matching was performed based on body mass index, age, and intraoperative defect size. Demographic and clinical data were recorded and compared. The statistical significance level was set at P < 0.05. RESULTS: Twenty patients underwent IH repair with preoperative BTX injections. Twenty patients who underwent IH repair without preoperative BTX injections were selected to comprise a 1:1 propensity-matched control cohort. The average defect size was 663.9 cm2 in the BTX group and 640.7 cm2 in the non-BTX group (P = 0.816). There was no difference in average age (58.6 vs 59.2 years, P = 0.911) and body mass index (33.0 vs 33.2 kg/m2, P = 0.911). However, there was a greater proportion of male patients in the BTX group (85% vs 55%, P = 0.082).Primary fascial closure was achieved in 95% of BTX patients and 90% of non-BTX patients (P = 1.0). Significantly fewer patients in the BTX group required component separation techniques to achieve primary fascial closure (65% vs 95%, P = 0.044). There was no significant difference in any postoperative surgical and medical outcomes. Hernia recurrence was 10% in the BTX group and 20% in non-BTX group (P = 0.661). CONCLUSIONS: In our study, we observed a lower rate of component separations to achieve primary fascial closure among patients with massive hernia defects who received preoperative BTX injections. These results suggest that preoperative BTX injections may "downstage" the complexity of hernia repair with abdominal wall reconstruction in patients with massive hernia defects and reduce the need for component separation.

Obesity as a Risk Factor in Cosmetic Abdominal Body Contouring: A Systematic Review and Meta-Analysis.

BACKGROUND: The incidence of obesity is on the rise around the globe. Outside of the massive weight loss (MWL) patient population, knowledge of risk factors associated with abdominal body contouring (BC) is limited. This systematic review and meta-analysis assesses the impact of obesity has on cosmetic abdominal BC outcomes. METHODS: A systematic review conducted in accordance with PRISMA 2020 was done. PubMed, Embase, Scopus, and COCHRANE databases were reviewed under search syntax "obesity," "abdominoplasty," "panniculectomy," and "body contouring" for articles. Cosmetic was defined as abdominoplasty or panniculectomy outside the context of MWL. Obesity was defined as BMI ≥ 30 kg/m2. Studies reporting postoperative outcomes with less than 50% of their population involving MWL patients were included. Postoperative outcomes were assessed by pooled analysis and meta-analysis. RESULTS: Of 3088 initial studies, 16 met inclusion criteria, and nine were used for pooled and meta-analysis. Meta-analysis demonstrated that obesity was associated with more seromas (OR 1.45, 1.06-1.98, p = 0.02), hematomas (OR 2.21, 1.07-4.57, p = 0.03), and total surgical site occurrences (OR 1.99, 1.30-3.04, p = 0.0016). There was no significant difference in odds of any other complications. Analysis by obesity class showed no significant increase in odds in seromas or wound dehiscence. CONCLUSIONS: This review demonstrates obesity increased odds of postoperative complications following cosmetic abdominal BC. However, risk of complications does not continue to increase with higher obesity class. A BMI ≥ 30 kg/m2 should not be a strict contraindication to cosmetic abdominal BC. Instead, plastic surgeons should evaluate patients on a case-by-case basis. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Impact of Implant Exchange Timing after Post-Mastectomy Radiation in Immediate Tissue Expander Breast Reconstruction: A Systematic Review.

BACKGROUND: The use of post-mastectomy radiation therapy (PMRT) in the setting of immediate two-stage breast reconstruction is becoming increasingly widespread. However, the timeframe of tissue expander exchange for permanent implant placement following PMRT is not well-defined, and it remains unclear what time interval optimizes surgical outcomes and patient satisfaction. METHODS: A systematic review conducted in accordance with PRISMA 2020 was completed. PubMed, Embase, Scopus, and Cochrane databases were searched under keywords pertaining to concepts of tissue expander breast reconstruction and PMRT. Inclusion criteria encompassed primary articles on tissue expander breast reconstruction with adjuvant radiation therapy reporting timing of exchange to permanent implant following radiation and surgical outcomes. RESULTS: Of the initial 1,259 publications, 15 studies met our inclusion criteria, and 11 studies had granular enough data to use for pooled analysis. Implant exchange less than 6 months after PMRT was found to be associated with increased incidence of wound dehiscence (17.12% vs 3.64%, p<0.001) and hematoma (25% vs 2.59%, p<0.001) compared to exchange after 6 months. There was no significant difference in incidence of SSI, seroma, capsular contracture, and reconstructive failure. CONCLUSIONS: Expander to implant exchange at less than 6 months is associated with a higher incidence of wound dehiscence and hematoma formation but does not increase the risk of reconstruction failure. The limited research on ideal timing prompts further investigation to optimize surgical outcomes for the increasing patient population undergoing PMRT and immediate two-staged breast reconstruction.

The Role of Dedicated Research Training in Promoting Academic Success in Plastic Surgery: Analysis of 949 Faculty Career Outcomes.

This study aimed to analyze the association between completion of research training and career success in American plastic surgery faculty to aid trainees in their decisions to perform research fellowships. Methods: A cross-sectional analysis of attending academic plastic surgeons in the United States was conducted. Outcomes were compared between faculty who completed research training (research fellowship, PhD, or MPH) and those who did not. Outcomes included promotion to full professor and/or department chair, h-index, and attainment of National Institutes of Health funding. Outcomes were analyzed using chi-squared tests, t tests, and multivariable regressions. Results: A total of 949 plastic surgery faculty members were included, and of those, 185 (19.5%) completed dedicated research training, including 13.7% (n = 130) who completed a research fellowship. Surgeons who completed dedicated research training were significantly more likely to achieve full professorship (31.4% versus 24.1%, P = 0.01), obtain National Institutes of Health funding (18.4% versus 6.5%, P < 0.001), and have a higher mean h-index (15.6 versus 11.6, P < 0.001). Dedicated research fellowships were independently predictive of achieving full professorship (OR = 2.12, P = 0.002), increased h-index (ß = 4.86, P < 0.001), and attainment of National Institutes of Health funding (OR = 5.06, P = 0.01). Completion of dedicated research training did not predict an increased likelihood of becoming department chair. Conclusion: The performance of dedicated research training was predictive of improved markers of career success in plastic surgery and should be considered beneficial in both the short and long term.

Advanced Endoscopic Rescue of a Complication (Duodenojejunostomy Leak) After a Pylorus-Preserving Pancreaticoduodenectomy in a Post-Esophagectomy Patient with Pancreatic Adenocarcinoma: A Case Report and Review of the Literature.

Background: Approximately 4% of patients develop a second upper gastrointestinal cancer after esophagectomy, and nearly 60,000 people are diagnosed with pancreatic cancer in the United States each year. The need for a Whipple procedure after esophagectomy is rarely reported. Post-esophagectomy anatomy, particularly the vascular supply, makes this a complex operation. Herein, we describe the advanced endoscopic rescue of a duodenojejunostomy (DJ) leak after pylorus-preserving pancreaticoduodenectomy (PPPD) in a post-esophagectomy patient. Presentation: A 72-year-old male with a remote history of esophageal cancer treated with minimally invasive three-hole esophagectomy and chemoradiation presented to our institution for evaluation and management of newly diagnosed pancreatic cancer. The patient had undergone common bile duct (CBD) stent placement by his gastroenterologist 2 weeks earlier after experiencing jaundice, weight loss, and steatorrhea. Endoscopic ultrasound confirmed the presence of a pancreatic head and neck mass, obstructing and dilating the main pancreatic duct and CBD. Fine-needle biopsy revealed a poorly differentiated adenocarcinoma. A PPPD was performed without intraoperative complications. The patient was subsequently readmitted with a DJ leak requiring interventional radiology and advanced endoscopic intervention. Conclusions: PPPD in patients with pancreatic cancer can be performed after previous esophagectomy. Careful dissection is crucial to avoid injury to the remaining right gastric and right gastroepiploic arteries that supply the gastric conduit after esophagectomy. The DJ is at risk after this operation, and access to tertiary care inclusive of interventional radiology and advanced endoscopic teams is critical to the correction and healing of a leak of this anastomosis.

Choroidal amelanotic tumours: clinical differentiation of benign from malignant lesions in 5586 cases.

PURPOSE: To investigate demographics and clinical features of patients with amelanotic choroidal tumours. DESIGN: Retrospective analysis. METHODS: Comparison of demographic and clinical features of various amelanotic choroidal tumours based on stratification by patient age, sex and tumour diameter. Included were all patients with amelanotic choroidal tumours evaluated on the Ocular Oncology Service, Wills Eye Hospital, Philadelphia, Pennsylvania, USA, over a 45-year time period. RESULTS: A total of 5586 amelanotic choroidal tumours in 4638 eyes of 4441 patients were included with a mean age at presentation of 58 years (median 60, range 0.1-100 years). Most patients were white (95%), female (56%) and with unilateral lesion (96%). By comparison, amelanotic melanoma presented at a younger mean age (57 years) compared with metastasis (60 years, p<0.001), nevus (61 years, p<0.001), lymphoma (65 years, p<0.001), sclerochoroidal calcification (70 years, p<0.001) and peripheral exudative haemorrhagic chorioretinopathy (80 years, p<0.001). Melanoma presented at an older mean age compared with osteoma (30 years, p<0.001), granuloma (42 years, p<0.001), haemangioma (49 years, p<0.001) and inflammatory choroidal lesions (49 years, p<0.001). Differences in race and sex were also seen between the various amelanotic choroidal lesions. With few exceptions, amelanotic melanoma had significantly larger basal diameter, greater thickness, more frequent association with subretinal fluid and more often ultrasonographically hollow, compared with other amelanotic choroidal lesions. CONCLUSION: Understanding the demographic and clinical features of amelanotic choroidal melanoma and other amelanotic lesions could lead to an earlier and more accurate diagnosis.

Suprachoroidal Hemorrhage Simulating Melanoma in Idiopathic Thrombocytopenic Purpura.

BACKGROUND: We report a case of suprachoroidal hemorrhage simulating choroidal melanoma in a patient with idiopathic thrombocytopenic purpura (ITP). METHODS: Case report. RESULTS: A 79-year-old white male with a history of lung adenocarcinoma, ITP, and mild anemia noted blurred vision with photopsia and floaters in the right eye (OD) that worsened over 2 months. He was found to have a pigmented choroidal mass and was referred for evaluation of possible choroidal melanoma. Visual acuity was 20/30 in the affected right eye and 20/25 in the left eye (OS). There was mild vitreous hemorrhage and 2 pigmented peripheral choroidal tumors in the temporal and nasal fundus OD. B-scan ultrasonography confirmed 2 acoustically hollow tumors, and transillumination demonstrated no shadowing. Optical coherence tomography over the lesions revealed choroidal elevation with suprachoroidal scalloped surface. Fluorescein and indocyanine green angiography revealed normal choroidal fluorescence and cyanescence with no "double circulation" of melanoma and no dye blockage, suggesting a suprachoroidal location. These findings were suggestive of suprachoroidal hemorrhage rather than melanoma. The patient was managed conservatively, and the hemorrhages demonstrated spontaneous resolution. CONCLUSION: Ocular manifestations of ITP are uncommon. Rarely, spontaneous suprachoroidal hemorrhage simulating melanoma can occur. A thorough clinical evaluation with multimodal imaging is critical to establishing the appropriate diagnosis.

Uveal metastasis in 1111 patients: Interval to metastasis and overall survival based on timing of primary cancer diagnosis.

PURPOSE: To evaluate interval between primary cancer diagnosis and uveal metastasis and assess survival outcomes based on whether the primary cancer was diagnosed before or after uveal metastasis. METHODS: In this retrospective analysis, all patients with uveal metastasis evaluated on the Ocular Oncology Service, Wills Eye Hospital, Philadelphia, PA, USA between February 1, 1974 and June 1, 2017 were included. Features and outcomes based on timing of primary cancer diagnosis, whether before or after diagnosis of uveal metastasis, were assessed. RESULTS: A total of 2214 uveal metastases were diagnosed in 1310 eyes of 1111 consecutive patients. Primary cancer was known prior to uveal metastasis in 742 patients (67%) and not known in 369 (33%). Of those not known, the primary cancer was later found in 192 patients (17%) and never found in 177 patients (16%). For those with known primary cancer, mean interval from primary cancer diagnosis to uveal metastasis was 5.2 years with differences in primary sites of gastrointestinal (2.1 years, p = 0.003), lung (2.2 years, p < 0.001), breast (6.5 years, p < 0.001), and thyroid (13 years, p < 0.001). By Kaplan-Meier analysis, the 5-year overall survival showed no difference between patients with primary cancer found before (28%) vs after (20%) vs never found (33%), relative to uveal metastasis. CONCLUSION: Of 1111 patients with uveal metastasis, early-onset uveal metastases were found with lung and gastrointestinal tract cancers, whereas late-onset metastases were found with breast and thyroid cancers. Overall survival did not vary on whether the primary tumor was diagnosed before, after, or never found, relative to uveal metastasis.

Effects of perineural invasion on biochemical recurrence and prostate cancer-specific survival in patients treated with definitive external beam radiotherapy.

OBJECTIVES: Perineural invasion (PNI) has not yet gained universal acceptance as an independent predictor of adverse outcomes for prostate cancer treated with external beam radiotherapy (EBRT). We analyzed the prognostic influence of PNI for a large institutional cohort of prostate cancer patients who underwent EBRT with and without androgen deprivation therapy (ADT). MATERIAL AND METHODS: We, retrospectively, reviewed prostate cancer patients treated with EBRT from 1993 to 2007 at our institution. The primary endpoint was biochemical failure-free survival (BFFS), with secondary endpoints of metastasis-free survival (MFS), prostate cancer-specific survival (PCSS), and overall survival (OS). Univariate and multivariable Cox proportional hazards models were constructed for all survival endpoints. Hazard ratios for PNI were analyzed for the entire cohort and for subsets defined by NCCN risk level. Additionally, Kaplan-Meier survival curves were generated for all survival endpoints after stratification by PNI status, with significant differences computed using the log-rank test. RESULTS: Of 888 men included for analysis, PNI was present on biopsy specimens in 187 (21.1%). PNI was associated with clinical stage, pretreatment PSA level, biopsy Gleason score, and use of ADT (all P<0.01). Men with PNI experienced significantly inferior 10-year BFFS (40.0% vs. 57.8%, P = 0.002), 10-year MFS (79.7% vs. 89.0%, P = 0.001), and 10-year PCSS (90.9% vs. 95.9%, P = 0.009), but not 10-year OS (67.5% vs. 77.5%, P = 0.07). On multivariate analysis, PNI was independently associated with inferior BFFS (P<0.001), but not MFS, PCSS, or OS. In subset analysis, PNI was associated with inferior BFFS (P = 0.04) for high-risk patients and with both inferior BFFS (P = 0.01) and PCSS (P = 0.05) for low-risk patients. Biochemical failure occurred in 33% of low-risk men with PNI who did not receive ADT compared to 8% for low-risk men with PNI treated with ADT (P = 0.01). CONCLUSION: PNI was an independently significant predictor of adverse survival outcomes in this large institutional cohort, particularly for patients with NCCN low-risk disease. PNI should be carefully considered along with other standard prognostic factors when treating these patients with EBRT. Supplementing EBRT with ADT may be beneficial for select low-risk patients with PNI though independent validation with prospective studies is recommended.

Controlling gold nanoparticle seeded growth in thermophilic ferritin protein templates.

Ferritin protein cages provide templates for inorganic nanoparticle synthesis in more environmentally-friendly conditions. Thermophilic ferritin from Archaeoglobus fulgidus (AfFtn) has been shown to encapsulate pre-formed 6-nm gold nanoparticles (AuNPs) and template their further growth within its 8-nm cavity. In this study, we explore whether using a gold complex with electrostatic complementarity to the anionic ferritin cavity can promote efficient seeded nanoparticle growth. We also compare wt AfFtn and a closed pore mutant AfFtn to explore whether the ferritin pores influence final AuNP size.

The impact of installing an MR scanner in the emergency department for patients presenting with acute stroke-like symptoms.

PURPOSE: We examined the impact of an MR scanner in the emergency department (ED) on ED length of stay (LOS), hospital (H) LOS, hospital admission rate, hospitalization costs, and ED re-presentation rate of patients presenting with stroke-like symptoms (SLS). We hypothesized that the ED MR would increase efficiency of patient care. METHODS: The number of MRIs performed in the ED vs. inpatient setting, EDLOS, HLOS, hospitalization charges, admission rate, discharge diagnoses, and 30-60-day ED re-presentation rates were determined for ED patients with SLS six months before (2011) and after (2012) ED MR installation. RESULTS: 362 and 448 patients with SLS presented to the ED, and 196 and 176 patients were admitted in 2011 and 2012 respectively. In 2011, 36 (18.4%) admitted patients, and, in 2012, 68 (38.6%) had MRIs in the ED, p<0.001. In 2011, 74 (37.8%) admitted patients were diagnosed with ischemic stroke, compared to 92 (52.3%) in 2012, p=0.007. HLOS was longer and charges higher for patients with stroke. No patients returned with a confirmed diagnosis of CVA or TIA within 0-60days after being discharged from the ED with negative MR. CONCLUSIONS: With the ED MR, more admitted patients 1) got scanned in the ED and 2) were diagnosed with stroke. Because this led to more patients on the stroke service actually suffering from strokes (and not other diagnoses), the overall HLOS and charges of patients presenting with SLS were not reduced by ED MR screening. Discharge after a negative ED MR did not incur risk of TIAs or strokes over the ensuing 60days. Therefore, not only does a dedicated MR scanner in the ED aid in the acute diagnosis of a CVA or other neurologic disorder, but it does so without the risk of under-diagnosing TIAs or evolving strokes in the presence of a negative MRI.

Structural-functional analysis of engineered protein-nanoparticle assemblies using graphene microelectrodes.

The characterization of protein-nanoparticle assemblies in solution remains a challenge. We demonstrate a technique based on a graphene microelectrode for structural-functional analysis of model systems composed of nanoparticles enclosed in open-pore and closed-pore ferritin molecules. The method readily resolves the difference in accessibility of the enclosed nanoparticle for charge transfer and offers the prospect for quantitative analysis of pore-mediated transport, while shedding light on the spatial orientation of the protein subunits on the nanoparticle surface, faster and with higher sensitivity than conventional catalysis methods.

Very High-Risk Localized Prostate Cancer: Outcomes Following Definitive Radiation.

PURPOSE: Existing definitions of high-risk prostate cancer consist of men who experience significant heterogeneity in outcomes. As such, criteria that identify a subpopulation of National Comprehensive Cancer Network (NCCN) high-risk prostate cancer patients who are at very high risk (VHR) for poor survival outcomes following prostatectomy were recently developed at our institution and include the presence of any of the following disease characteristics: multiple NCCN high-risk factors, primary Gleason pattern 5 disease and/or ≥5 biopsy cores with Gleason sums of 8 to 10. Whether these criteria also apply to men undergoing definitive radiation is unclear, as is the optimal treatment regimen in these patients. METHODS AND MATERIALS: All men consecutively treated with definitive radiation by a single provider from 1993 to 2006 and who fulfilled criteria for NCCN high-risk disease were identified (n=288), including 99 patients (34%) with VHR disease. Multivariate-adjusted competing risk regression models were constructed to assess associations between the VHR definition and biochemical failure (BF), distant metastasis (DM), and prostate cancer-specific mortality (PCSM). Multivariate-adjusted Cox regression analysis assessed the association of the VHR definition with overall mortality (OM). Cumulative incidences of failure endpoints were compared between VHR men and other NCCN high-risk men. RESULTS: Men with VHR disease compared to other NCCN high-risk men experienced a higher 10-year incidence of BF (54.0% vs 35.4%, respectively, P<.001), DM (34.9% vs 13.4%, respectively, P<.001), PCSM (18.5% vs 5.9%, respectively, P<.001), and OM (36.4% vs 27.0%, respectively, P=.04). VHR men with a detectable prostate-specific antigen (PSA) concentration at the end of radiation (EOR) remained at high risk of 10-year PCSM compared to VHR men with an undetectable EOR PSA (31.0% vs 13.7%, respectively, P=.05). CONCLUSIONS: NCCN high-risk prostate cancer patients who meet VHR criteria experience distinctly worse outcomes following definitive radiation and long-term androgen deprivation therapy, particularly if an EOR PSA is detectable. Optimal use of local therapies for VHR patients should be explored further, as should novel agents.

Seasonal, geographic, and antimicrobial resistance patterns in microbial keratitis: 4-year experience in eastern Pennsylvania.

PURPOSE: The aim of this study was to review the demographics, causative organisms, seasonal and geographic variation, and antimicrobial resistance patterns of microbial keratitis at our institution over a 4-year period. METHODS: Electronic medical records of all patients with microbial keratitis who underwent corneal culturing at a single institution in eastern Pennsylvania between January 1, 2009 and December 31, 2012 were reviewed. RESULTS: A total of 311 patients representing 323 instances of infectious keratitis were analyzed. The most frequently implicated organisms in contact lens-related infections were Pseudomonas aeruginosa for bacteria and Fusarium species for fungus, compared with Staphylococcus aureus and Candida species in non-contact lens-associated bacterial infections. Bacterial keratitis occurred most frequently in spring and least frequently in winter (P = 0.024). Patients who live in large fringe metro (suburban) areas accounted for the highest proportion of infectious keratitis cases. P. aeruginosa and methicillin-sensitive S. aureus isolates were highly susceptible to fluoroquinolones, whereas 32% of coagulase-negative staphylococcus isolates tested were resistant to moxifloxacin and gatifloxacin, and all methicillin-resistant S. aureus organisms tested were resistant to these 2 fluoroquinolones. No organisms tested were resistant to tobramycin, gentamicin, or vancomycin. No fungal infections tested were resistant to voriconazole. CONCLUSIONS: Most infectious keratitis occurred in nonwinter months and in patients from suburban counties. Although fluoroquinolones were effective against the most common bacteria, staphylococcal species exhibited a high rate of resistance, representing a therapeutic challenge given the increasing use of fluoroquinolones as first-line monotherapy. No organisms tested were resistant to tobramycin, gentamicin, vancomycin, or voriconazole.