Retrospective Study of Acanthamoebic Keratitis During the Past 10 Years

May 5, 2016 updated by: National Taiwan University Hospital

Retrospective Study of the in Vivo Confocal Microscopic Findings and the Treatment Outcome of Acanthamoebic Keratitis

Acanthamoebic keratitis is an important corneal disease which may cause severe complication. The difficulty in diagnosis, the difficulty in treatment, and the long treatment process are factors leading to the poor prognosis of these patients. In this retrospective study, the investigators try to analyze the tissue proven Acanthamoebic keratitis diagnosed in our hospital. The investigators will focus on the in vivo confocal microscopic results, the medical history and the medical/surgical treatment outcome. The investigators will collect the tissue proven cases according to the data provided by laboratory diagnosis department and pathological department. The in vivo confocal microscopic results will be collected and analyzed. The investigators will also look through the photography of the external eyes from data stored in PAC system. The medical history and treatment outcome will be studied from clinical chart review. From this study, the investigators aimed to find out a easy way of diagnosing Acanthamoebic keratitis from in vivo confocal microscopy, and find out a better way for treatment.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Acanthamoeba keratitis (AK), caused by a pathogenic amoeba, is a sight-threatening corneal infection with severe pain, epithelial defect, epithelial haze, pseudodendrites, and, most characteristically, radial keratoneuritis. The corneal infection of AK was first recognized in the mid 1970s. Since then, a growing number of AK cases were diagnosed, mainly resulting from improper use of soft contact lenses.

Clinical diagnosis of AL is difficult, especially in the early phases of the disease, and it often is misdiagnosed and treated as a herpes simplex infection. It was reported a diagnostic delay of more than 18 days between onset of symptoms and start of anti- amoebic treatment results in a poor disease progress. While definitive diagnosis is made by confirmation of Acanthamoeba cysts or trophozoites in corneal lesions by staining, corneal biopsy, or tissue culturing.

In vivo confocal microscopy was considered useful in the rapid diagnosis of AK. The Acanthamoeba cysts were observed almost exclusively in the epithelial cell layer as highly reflective, round or stellate, high-contrast particles with a diameter of 10 to 20 μm. It was suggested that invasion of Acanthamoeba cysts into Bowman's layer may be a useful predictor for a persistent clinical course. The trophozoites are pear-shaped or irregularly wedge-shaped structures, some surrounded by a brilliant halo some exhibiting fine pseudopodia-like extensions, with mean size of 30.2 µm (range 19.2-55.6μm). It was reported to present in cornea stroma. Highly reflective activated keratocytes forming a honeycomb pattern change was reported to be present around the keratoneuritis. In addition, infiltration of inflammatory cells, possibly polymorphonuclear cells, was observed along with the keratocytes in cases of AK. However, the in vivo confocal microscopic findings in patients with AK is still limited. Some clinical findings may not be correlated with the reports published before.

John K.G. et al recommended clinical treatment toward Acanthamoeba keratitis using Diamidine and Biguanide which are the only two proofed Acanthamoeba cysticidal medication, while Metronidazole is effective in vivo but not in vitro. Topical steroid was considered rather controversial but important and beneficial. It was recommended to use a minimum of 2 weeks of Biguanide prior to the use of topical steroid for inflammation control. When Acanthamoeba keratitis was diagnosed early in the disease course, topical steroid can be spared for the immediate using Diamidine and Biguanide to kill pathogen. In a United Kingdom multicenter study of 218 patients, the average duration of medical therapy was 6 months (range, 0.5 to 29 months). In 2011, a little over half of respondents using corticosteroids in the treatment of Acanthamoeba keratitis. Surgical managements including epithelial debridement, cryotherapy and corneal graft surgery may itself be therapeutic if performed early and promote penetration. Therefore, when Acanthamoeba keratitis was suspected, a long-term and immediate medical treatment may be needed ,and the use of topical steroid toward Acanthamoeba keratitis is still worth investigating.

Study Type

Observational

Enrollment (Anticipated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Taiwan
      • Taipei, Taiwan, 100
        • Recruiting
        • National Taiwan University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

10 years to 90 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The in vivo confocal microscopic data and medical records of all recruited patients diagnosed with Acanthamoeba Keratitis will be reviewed after approved by the NTUH Institutional Review Board Committee. Data collected include patient demographics (age, gender), local findings, external eye photos, treatment course and treatment outcome. In vivo confocal microscope exam results will be compared with the clinical manifestation.

Description

Inclusion Criteria:

  • presenting to National Taiwan University Department from Jun. 1st, 2003 to dec. 30th , 2016
  • suspecting Acanthamoeba Keratitis by the ophthalmologist
  • drug treatment as Acanthamoeba Keratitis successed
  • tissue proved to be Acanthamoeba Keratitis
  • referred from the other hospital with the diagnose of Acanthamoeba Keratitis

Exclusion Criteria

  • patients suspect corneal Acanthamoeba Keratitis from Jun. 1st, 2003 to dec. 30th , 2013, but without in vivo confocal data, or complete chart records.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Retrospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
patients diagnosed with acanthamoeba keratitis

Inclusion Criteria:

- All patients presenting to National Taiwan University Department from Jun. 1st, 2003 to dec. 30th , 2016 with the tissue proven corneal AK will be included.

Exclusion Criteria

- Patients with tissue proven corneal AK during from Jun. 1st, 2003 to dec. 30th , 2016, but without in vivo confocal data, or complete chart records.
Other: no intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Number of participants with typical image finding under an in vivo confocal microscope (Confoscan 3.4.1; Nidek Technologies, Padova, Italy)
Time Frame: through study completion, an average of about 10 year microscope diagnosis and disease progress prediction of patients with Acanthamoe
through study completion, an average of about 10 year microscope diagnosis and disease progress prediction of patients with Acanthamoe

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Taiwan University Hospital

Investigators

  • Study Director: Wei-Li Chen, MD,PHD, professor of National Taiwan University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2014

Primary Completion (Anticipated)

June 1, 2016

Study Completion (Anticipated)

July 1, 2016

Study Registration Dates

First Submitted

April 12, 2016

First Submitted That Met QC Criteria

May 4, 2016

First Posted (Estimate)

May 5, 2016

Study Record Updates

Last Update Posted (Estimate)

May 9, 2016

Last Update Submitted That Met QC Criteria

May 5, 2016

Last Verified

May 1, 2016

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 201312046RINB

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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