Microbial keratitis following vegetative matter injury

Microbial keratitis in Stevens-Johnson syndrome: Clinical and microbiological profile

PURPOSE

To study the clinical and microbiological profile of microbial keratitis in Stevens-Johnson syndrome (SJS).

STUDY DESIGN

Case series.

PARTICIPANTS

Patients with SJS who developed microbial keratitis.

METHODS

Medical records and microbiological data of patients with SJS who developed microbial keratitis from January 1991 to December 2012 were reviewed. We analysed the type of causative organisms and their antibiotic susceptibility along with the clinical pattern and responses to medications in this group of patients.

MAIN OUTCOME MEASURE

Clinical and microbiological profile of microbial keratitis.

RESULTS

We reviewed 65 eyes of 60 patients seen between January 1991 and December 2012. Positive microbiological culture results were obtained in 45 eyes (69.2%). Isolated bacterial infections were noted in 27 eyes (60%) while isolated fungal growth was seen in 1/45 eyes (2.2%). Polymicrobial infections were noted in 17/45 eyes (37.8%). The most common bacteria isolated were Staphylococcus species (35%). The median duration of SJS before presentation was 5 months (IQR, 2 months to 7 years) with 50% presenting within four months of the onset of SJS. Twenty-eight eyes (43%) needed treatment in addition to antibiotics for resolution of tarsorraphy, epilation, tissue adhesive application, and amniotic membrane grafting or punctal cautery. The average time for resolution was 25 days.

CONCLUSION

Microbial keratitis in SJS patients is different from patients without SJS in presentation and the response to medications. It requires a multi-disciplinary approach for healing.

Corneal Debridement Combined with Intrastromal Voriconazole for Recalcitrant Fungal Keratitis

Background

To analyze the therapeutic effects of corneal debridement combined with intrastromal voriconazole in recalcitrant fungal keratitis.

Methods

This is a retrospective study. Fourteen patients with recalcitrant fungal keratitis were treated by corneal debridement combined with intrastromal voriconazole (50 μg/0.1 ml). This paper reviews and analyzes the patients' basic state, surgical intervention, medicinal treatment, and outcomes.

Results

The mean sizes of infiltration and ulcer were (5.54 ± 1.32)mm and (3.46 ± 1.03)mm, respectively, and the mean depth was (315.43 ± 57.72)μm. Twelve of the patients had satellite lesion, and 2 suffered hypopyon. After intrastromal voriconazole, the size of infiltration decreased significantly to (4.32 ± 1.10)mm (P < 0.001), but there was no significant change in ulcer size ((3.36 ± 0.92)mm, P = 0.082). Thirteen patients were cured after corneal debridement. The mean healing time was (15.38 ± 7.38) days. Excluding one cured patient with optic nerve atrophy and one patient for whom the treatment failed, the mean best-corrected visual acuity after healing was (0.23 ± 0.18)LogMAR, a significant improvement compared to pretreatment (0.87 ± 0.57(LogMAR), P = 0.01). The mean corneal astigmatism was (1.3 ± 1.6)D of 12 cured patients after healing and (1.0 ± 0.7)D at final follow-up, and there was no significant difference (P = 0.374).

Conclusions

Corneal debridement combined with intrastromal voriconazole is a secure and effective treatment for recalcitrant fungal keratitis.

Fungal Keratitis Associated With Airborne Organic Debris and Soft Contacts Lenses: Case Reports and Review of the Literature

OBJECTIVES

To report two cases of fungal keratitis in soft contact lens wearers who were exposed to environmental mold.

METHODS

Case reports, with review of the relevant literature.

RESULTS

Two otherwise healthy middle-aged women who were soft contact lens wearers developed fungal keratitis about 1 week after heavy exposure to environmental mold. Culture results showed Aspergillus from one patient and the unusual combination of Trichoderma and Penicillium from the other. Both were treated with topical natamycin, topical fluoroquinolone antibiotic prophylaxis, and periodic ulcer debridement. After many weeks of treatment, both ulcers healed with subsequent scarring. Because the ulcers were located in the peripheral cornea in both cases, excellent final visual acuities were achieved. Fungal keratitis cases like these are rarely seen at our referral clinic, which is located in the temperate climate of northeastern Indiana.

CONCLUSIONS

In addition to the usual recommended contact lens care guidelines, it may be prudent for eye care providers to warn patients against wearing their contact lenses in situations likely to result in heavy exposure to organic matter or, at the very least, to wear tight-fitting goggles for eye protection.

Seasonal Variation in the Presentation of Infectious Keratitis

INTRODUCTION

Infectious keratitis is a common ophthalmic disease with the potential for severe ocular morbidity. Multiple studies have described various risk factors for the development of infectious keratitis. The purpose of this study was to analyze the seasonal variation in the presentation of infectious keratitis, and also seasonal changes in its etiologies and risk factors.

METHODS

A retrospective chart review was performed on consecutive patients presenting to the emergency department at our tertiary care urban hospital center who were diagnosed with infectious keratitis from 2008 to 2013. A chi-square analysis was performed to determine whether a significant seasonal variation existed between the month, season, frequency of presentation of ulcers, and other risk factors.

RESULTS

A total of 155 patients-53 men and 102 women-with a mean age of 40 (range, 3-97; median, 36) diagnosed with infectious keratitis were included in the analysis. Sixty-nine (44.5%) ulcers presented in the summer, 19 (12.3%) in the fall, 34 (21.9%) in the winter, and 33 (21.3%) in the spring (P<0.0001). Seventeen (11%) patients experienced diabetes mellitus, 60 (39%) were contact lens wearers, 12 (8%) ulcers occurred in the setting of trauma, and 19 (12%) patients underwent previous ocular surgery. A total of 92 ulcers were cultured, of which 53.8% were positive in the summer, 42.9% in the fall, 55.0% in the winter, and 42.1% in the spring. A significant seasonal variation in the frequency of 1 organism, Pseudomonas aeruginosa, was identified (P=<0.0001); up to 47.6% of culture-positive ulcers in the summer were P. aeruginosa positive, whereas cultures in the remaining seasons were 0, 9.1% and 12.5% positive for this organism.

DISCUSSION

The summer months have a higher frequency of infectious keratitis and P. aeruginosa positivity in this study. Possible factors leading to this increased summer presentation include warmer temperatures, higher humidity, and greater ocular exposure to water. Clinicians should increase their vigilance and education to high-risk patients during these periods and potentially modify empiric treatment regimens.

Methods for In Vivo/Ex Vivo Analysis of Antimicrobial Peptides in Bacterial Keratitis: siRNA Knockdown, Colony Counts, Myeloperoxidase, Immunostaining, and RT-PCR Assays

Antimicrobial peptides (AMPs) are essential components of the innate immune response. They have direct killing ability as well as immunomodulatory functions. Here, we describe techniques to identify specific AMPs involved in the protection against microbial keratitis, a vision threatening infection of the cornea of the eye which is the most serious complication of contact lens wear. Specifically we detail the use of siRNA technology to temporarily knockdown AMP expression at the murine ocular surface in vivo and then describe ex vivo assays to determine the level of bacteria, relative number of neutrophils, and levels of cytokines, chemokines, and AMPs in infected corneas.

[Diagnostic and therapeutic contribution of microbiological analysis in severe microbial keratitis at Reims University Hospital between 2012 and 2014]

PURPOSE

To investigate the contribution of microbial analysis in the diagnosis and management of severe microbial keratitis.

MATERIAL AND METHOD

This is a monocentric retrospective study at the University Hospital of Reims from January 2012 to December 2014. Corneal scrapings with infectious keratitis were subjected to routine bacterial and fungal culture. PCR was also performed to detect various viral DNA (VZV, CMV, EBV, HSV 1 & 2, adenovirus) and Acanthamoeba sp. DNA. All contact lens cases were analyzed if available.

RESULTS

One hundred and six patients were hospitalized, including 30 contact lens wearers (28.3%). Sixty-four bacterial cultures were positive (68%). Twenty-five different bacterial species were identified with a majority of gram-positive bacteria (67.92%). Among contact lens wearers, the initial VA was better than non-wearers (P=0.0004) and 37% of bacteria identified (a plurality) were gram positive. Of 11 contact lens case analyzed, in only one case (3.3%) did the result correlate with the corneal culture. Only 9 samples from the 323 viral DNA extractions and real time PCR were positive (2.8%); 7 were HSV1. No prior antiviral therapy had been started. Fungal culture was positive in 2 of the 97 corneal samples taken and 63.6% of the contact lens cases (7/11 cases). Only one of the 40 Acanthamoeba sp. PCR's was positive.

CONCLUSION

The systematic performance of microbiological investigations is a good diagnostic approach given the polymorphism of clinical presentations of corneal ulcers, which can sometimes be extremely misleading. Culture of contact lens cases appears ineffective for the detection and determination of the causative microorganism. The high incidence of Staphylococcus in bacterial keratitis and the prevalence of infections with gram-positive bacteria in contact lens wearers were noted.

First unusual case of keratitis in Europe due to the rare fungus Metarhizium anisopliae

Metarhizium anisopliae is a fungus utilized worldwide for insect-pest biocontrol. Few M. anisopliae infections have been reported previously. Here, M. anisopliae was isolated from a corneal ulcer in a healthy man. It is the first ocular case in France and Europe of this extremely rare fungus in humans.