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The Antibiogram and Outcomes of Antimicrobial Regimens in Microbial Keratitis: A Prospective Cohort Study

Evaluation of Antibiogram Results and Clinical Response to Prescribed Antimicrobials in Microbial Keratitis Patients

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT05655689
Enrollment
123
Registered
2022-12-19
Start date
2021-12-31
Completion date
2023-01-01
Last updated
2024-01-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bacterial Keratitis, Fungal Keratitis, Microbial Keratitis, Mixed Bacterial and Fungal Keratitis

Keywords

Microbial keratitis, Infectious corneal ulcer, Bacterial keratitis, Fungal keratitis, Mycotic keratitis, Antibiogram, Antimicrobial resistance, Culture, Sensitivity, Fortified antibiotics eye drops, Moxifloxacin, Natamycin, Voriconazole, Prevalence, Antifungal eye drops, Bacteria, Fungi, Vancomycin, Ceftazidime, Gentamicin, Mixed bacterial and fungal keratitis

Brief summary

This study is an observational prospective cohort study which aims to generate an antibiogram and to assess the clinical responses and outcomes of microbial keratitis patients, treated with empiric topical antimicrobial therapies, with the main objective being to recommend the most effective empiric therapy. Microbial keratitis patients are attending the Cornea Outpatient Clinic at Alexandria Main University Hospital, Alexandria, Egypt.

Detailed description

The main objective of this observational study is to recommend the most effective empiric topical antimicrobial therapy in microbial keratitis, according to the current local antimicrobial resistance data and the clinical outcomes of patients with bacterial, fungal, and mixed bacterial and fungal keratitis being treated with different empiric topical antibiotics and antifungal therapies. In the study, test results of routinely performed culture and sensitivity on corneal scraping samples and on contact lenses in indicated severe, centrally located, and large ulcers are collected and analyzed. The sensitivity data is utilized to generate an antibiogram to describe the local prevalence of bacteria and fungi causing microbial keratitis and to investigate the prevalence of antimicrobial resistance. Results of the culture and sensitivity are often delayed, hence empiric broad- spectrum antimicrobial therapy is ideally started after corneal scraping, until laboratory test results are obtained. Broad-spectrum empiric therapy will be modified into a more selective culture- guided therapy if the causative agent and its antimicrobial sensitivity are identified. Empiric therapy continues in cases where the culture results are negative together with clinical improvement. Also, when patients have already been on empiric treatment before presenting to the clinic, corneal scraping and culture are not performed. In the study, microbial keratitis patients diagnosed as either bacterial, fungal, or mixed bacterial and fungal keratitis, taking the empiric topical antimicrobials, are observed. The study investigator 's role is to observe and study the clinical responses and treatment outcomes of microbial keratitis patients who are on different empiric antimicrobial therapies as part of the routine medical care. There is no assignment of any intervention to the study participants. The investigator does not intervene, and does not prescribe, recommend, or assign any intervention to the study participants. The clinical response of microbial keratitis patients, who are on different empiric antibiotics and antifungal eye drops, is studied by determining the primary and secondary outcomes. Measured outcomes include corneal ulcer healing, time to epithelialization, improvement in visual acuity, rates of surgical interventions and complications.

Interventions

In the observational study, patients treated with topical antibiotic moxifloxacin 0.5% eye drops as part of routine medical care are observed. The investigator does not assign any specific intervention to the study participants.

DRUGCeftazidime 5% + vancomycin 5%

In the observational study, patients treated with topical fortified antibiotics ceftazidime 5% and vancomycin 5% eye drops as part of routine medical care are observed. The investigator does not assign any specific intervention to the study participants.

DRUGGentamicin 1.4% + vancomycin 5%

In the observational study, patients treated with the topical fortified antibiotics gentamicin 1.4% and vancomycin 5% eye drops as part of routine medical care are observed. The investigator does not assign any specific intervention to the study participants.

DRUGNatamycin 5% Oph Susp

In the observational study, patients treated with the topical natamycin 5% antifungal eye drops as part of routine medical care are observed. The investigator does not assign any specific intervention to the study participants.

DRUGVoriconazole 1%

In the observational study, patients treated with voriconazole 1% antifungal eye drops as part of routine medical care are observed. The investigator does not assign any specific intervention to the study participants.

DRUGNatamycin 5% + voriconazole 1%

In the observational study, patients treated with the topical natamycin 5% and voriconazole 1% antifungals eye drops as part of routine medical care are observed. The investigator does not assign any specific intervention to the study participants.

DRUGNatamycin 5%+ ceftazidime 5% + vancomycin 5%

In the observational study, patients treated with the topical natamycin 5% and antifungal and the fortified antibiotic ceftazidime 5% and vancomycin 5% eye drops as part of routine medical care are observed. The investigator does not assign any specific intervention to the study participants.

DRUGVoriconazole 1% + ceftazidime 5% + vancomycin 5%

In the observational study, patients treated with the topical voriconazole 1% antifungal and the fortified antibiotics ceftazidime 5% and vancomycin 5% eye drops as part of routine medical care are observed. The investigator does not assign any specific intervention to the study participants.

Sponsors

Alexandria University
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
1 Years to 90 Years
Healthy volunteers
No

Inclusion criteria

* Patients diagnosed with bacterial keratitis either clinically or by culture. * Patients diagnosed with fungal keratitis either clinically or by culture. * Patients diagnosed with mixed bacterial and fungal keratitis either clinically or by culture.

Exclusion criteria

* Patients diagnosed with corneal abrasions and non-infectious corneal ulcers. * Patients diagnosed with acanthamoeba keratitis as a single causative agent. * Patients diagnosed with viral keratitis as a single causative agent. * Patients who are noncompliant to treatment.

Design outcomes

Primary

MeasureTime frameDescription
Corneal ulcer healing4 months from participationAn ulcer is recognized as healed when there is a lack of epithelial defect, and no infiltrates. This is detected by the routine examination under the cobalt-blue light of the slit lamp biomicroscope. The absence of fluorescein staining when fluorescein is applied to the ulcer indicates an intact epithelium.
The time to epithelialization4 months from participationThe time required to re-epithelialization of the corneal ulcer is measured in days.
The antibiogram generation4 months from participationThe corneal scraping culture and sensitivity test results are collected to produce the local antibiogram. Antimicrobial susceptibility is determined using the standard agar disc-diffusion method (Kirby-Bauer) by measuring the zone of inhibition. For each isolate, percentage susceptibility to the antimicrobial is calculated by dividing the number of susceptible isolates by the total number of tested isolates.

Secondary

MeasureTime frameDescription
Corneal melting4 months from participationThe percentage of corneal melting is calculated. Corneal melting is clinically diagnosed by the slit lamp biomicroscope examination.
The best spectacle-corrected visual acuity4 months from participationThe best spectacle-corrected visual acuity (BCVA) is routinely measured using the Snellen chart. The baseline (BCVA) and the post-treatment (BCVA) are recorded as decimal values of Snellen fractions. For patients with very low vision, the semiquantitative scale of counting fingers (CF), hand motion (HM), perception of light (PL) and no perception of light (NPL) is quantified by their conversion into the equivalent decimal values using the Freiburg Visual Acuity Test (FrACT). The improvement in (BCVA) is measured by finding the difference between the post-treatment BCVA and the baseline BCVA.
Corneal opacities4 months from participationThe percentage of corneal opacities is calculated. The presence of corneal opacity is detected by the slit lamp biomicroscope examination.
Surgical interventions4 months from participationThe percentage of surgical interventions is calculated. An example of surgical intervention is therapeutic penetrating keratoplasty (TKP)
Corneal perforations4 months from participationThe percentage of corneal perforations is calculated. Corneal perforations are routinely tested by the Seidel test on slit lamp biomicroscope examination with cobalt blue light.

Countries

Egypt

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 9, 2026