Microbial KeratitisNCT05888883
Microbial Keratitis Sampling for Biomarker Discovery
An observational study of Microbial Keratitis, run by University of Edinburgh at 1 site in United Kingdom.
Trial summary
The goal of this observational study is to identify prognostic and/or diagnostic signatures (biomarkers) related to microbial keratitis outcomes. We will compare tear and ocular swab samples from participants currently suffering from microbial keratitis to healthy control participants. Read more about this study
- Who is it for?
- Ages 16 years and olderHealthy volunteers can take part
- Conditions the study is for
- Microbial Keratitis
- How many people
- 13 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 1 Aug 2023to 1 Aug 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Study population: Study participants with suspected microbial keratitis will be recruited and consented at their first presentation at the Ophthalmology Acute Referral Clinic, or on-call service at the Princess Alexandra Eye Pavilion, Edinburgh, UK. Healthy control volunteer participants will be recruited from the University of Edinburgh by email invitation or by word-of-mouth
Who may be able to join
- 16 years old or older.
- Able to provide informed consent for themselves.
- Patient group: Appearances typical of a new infective keratitis of the cornea, in one eye only.
- Control group: healthy volunteers with no recent history (within 1 year) of MK or inflammatory eye condition.
Who cannot join
- <16 years old.
- Not able to provide consent for themselves.
- Patients with suspected viral rather than bacterial/fungal corneal infection, such as herpetic keratitis.
- Patients who present with MK in both eyes.
- Control group: Individuals receiving topical steroid or antimicrobial therapy to the eye, or any other form of systemic immunosuppression/antimicrobial drug.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Princess Alexandra Eye Pavilion (NHS Lothian)
Edinburgh, Scotland, EH3 9HA
About this study
The goal of this observational study is to identify prognostic and/or diagnostic signatures (biomarkers) related to microbial keratitis outcomes. We will compare tear and ocular swab samples from participants currently suffering from microbial keratitis to healthy control participants.
The primary study objective is to undertake analysis (proteomics and metabolomics) of microbial keratitis patient (and healthy control) ocular samples collected throughout the patient treatment course to better understand the ocular microenvironment and to identify candidate biomarkers for future targeted screening and validation studies.
Read more
The secondary study objective is to define the microorganisms in patients with microbial keratitis through a better understanding of the ocular surface micro/mycobiome (the resident bacteria and fungi) in health and disease
Participants will have their tears collected via capillary tube during their treatment course, and swabs of their conjunctiva collected at their first and final appointments.
Read the detailed description
Microbial keratitis (MK) (infection of the cornea) is a leading cause of blindness globally with an incidence of >2m cases per year (particularly across Low and Middle Income Countries - LMICs), and a common acute eye disease in Edinburgh (~ 100 cases treated at the Princes Alexandra Eye Pavilion (PAEP) per year). MK is an "ophthalmic emergency" and even where gold-standard diagnostics and treatment are available, over 60% of MK patients are still left with visual impairment across LMICs, and >10% of patients require expensive and often unsuccessful surgical interventions such as corneal transplant. These permanent, debilitating outcomes are often attributed to an excessive and uncontrolled immune response, leading to scarring and corneal perforation.
Despite this, current diagnostic and treatment strategy targets only the invading pathogen and does not address the host response. Even where microbiological evaluation is conducted, the average culture-positive rate is just 50% and Gram-stain positivity is reported between 27.3%-61.6%2. Where microbiological evaluation is not possible, antimicrobials are prescribed empirically and often inappropriately, potentially contributing to the emergence of antimicrobial resistance (AMR) and worsening outcomes.
We are seeking to better understand the inflammatory response and the host-pathogen interactions to develop improved diagnostics and alternative treatment strategies. We propose to achieve this by studying the tears and the conjunctiva of those currently with, and without MK to identify biomarkers which can be utilised to achieve these goals.
Research Question: Can prognostic and diagnostic signatures (biomarkers) for MK be identified from patient ocular samples (tears and swabs)?
Hypothesis: Biomarkers will be identified through proteomic/metabolomic and micro/mycobiome analysis of patient ocular samples and these can provide us with more information about the disease and could inform the development of novel diagnostic platforms and possible alternative treatment strategies.
- Conditions
- Microbial Keratitis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Microbial Keratitis Participants | Up to 50 participants presenting with clinically suspected microbial keratitis will be recruited from the Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh | |
| Healthy Control Participants | Up to 20 participants with no history of microbial keratitis will be recruited. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Globally measure, list and compare the peptides extracted from ocular tear samples of participants with and without the disease (microbial keratitis) throughout the infection course.
Identify any proteomic signatures of disease prognosis
Measured: 5 years
Globally measure, list and compare the metabolites extracted from ocular tear samples of participants with and without the disease (microbial keratitis) throughout the infection course.
Identify any metabolomic signatures of disease prognosis
Measured: 5 years
Secondary outcomes (1)
Measure, list and compare microorganisms (bacteria and fungi) extracted from ocular swab samples of participants with and without the disease (microbial keratitis)
Relative abundance of bacterial/fungal species between groups
Measured: 5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jun 2023
- Study start1 Aug 2023
- Primary completion1 Aug 2025
- Study completion1 Aug 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Microbial KeratitisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 13 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Edinburgh
- Sponsor type
- University, hospital or other
- Collaborators
- NHS Lothian
- Responsible party
- Sponsor
- Investigators
- Naing Latt Tint, FRCOphth, Principal investigator, NHS Lothian
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05888883
- Sponsor's protocol ID
- 2023/0017
- Status last verified
- Aug 2025
- First submitted
- 24 May 2023
- Last updated
- 26 Aug 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 26 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Microbial Keratitis Sampling for Biomarker Discovery
- ClinicalTrials.gov ID
- NCT05888883
- Acronym / sponsor ID
- 2023/0017
- Conditions
- Microbial Keratitis
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 13 participants (actual)
- Lead sponsor
- University of EdinburghUniversity, hospital or other
- Collaborators
- NHS Lothian
- Study start
- 1 Aug 2023 (actual)
- Primary completion
- 1 Aug 2025 (actual)
- Study completion
- 1 Aug 2025 (actual)
- First posted
- 5 Jun 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this observational study is to identify prognostic and/or diagnostic signatures (biomarkers) related to microbial keratitis outcomes. We will compare tear and ocular swab samples from participants currently suffering from microbial keratitis to healthy control participants.
The primary study objective is to undertake analysis (proteomics and metabolomics) of microbial keratitis patient (and healthy control) ocular samples collected throughout the patient treatment course to better understand the ocular microenvironment and to identify candidate biomarkers for future targeted screening and validation studies.
The secondary study objective is to define the microorganisms in patients with microbial keratitis through a better understanding of the ocular surface micro/mycobiome (the resident bacteria and fungi) in health and disease
Participants will have their tears collected via capillary tube during their treatment course, and swabs of their conjunctiva collected at their first and final appointments.
Detailed description
Microbial keratitis (MK) (infection of the cornea) is a leading cause of blindness globally with an incidence of >2m cases per year (particularly across Low and Middle Income Countries - LMICs), and a common acute eye disease in Edinburgh (~ 100 cases treated at the Princes Alexandra Eye Pavilion (PAEP) per year). MK is an "ophthalmic emergency" and even where gold-standard diagnostics and treatment are available, over 60% of MK patients are still left with visual impairment across LMICs, and >10% of patients require expensive and often unsuccessful surgical interventions such as corneal transplant. These permanent, debilitating outcomes are often attributed to an excessive and uncontrolled immune response, leading to scarring and corneal perforation.
Despite this, current diagnostic and treatment strategy targets only the invading pathogen and does not address the host response. Even where microbiological evaluation is conducted, the average culture-positive rate is just 50% and Gram-stain positivity is reported between 27.3%-61.6%2. Where microbiological evaluation is not possible, antimicrobials are prescribed empirically and often inappropriately, potentially contributing to the emergence of antimicrobial resistance (AMR) and worsening outcomes.
We are seeking to better understand the inflammatory response and the host-pathogen interactions to develop improved diagnostics and alternative treatment strategies. We propose to achieve this by studying the tears and the conjunctiva of those currently with, and without MK to identify biomarkers which can be utilised to achieve these goals.
Research Question: Can prognostic and diagnostic signatures (biomarkers) for MK be identified from patient ocular samples (tears and swabs)?
Hypothesis: Biomarkers will be identified through proteomic/metabolomic and micro/mycobiome analysis of patient ocular samples and these can provide us with more information about the disease and could inform the development of novel diagnostic platforms and possible alternative treatment strategies.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Microbial Keratitis Participants | – | –Up to 50 participants presenting with clinically suspected microbial keratitis will be recruited from the Princess Alexandra Eye Pavilion, NHS Lothian, Edinburgh |
| Healthy Control Participants | – | –Up to 20 participants with no history of microbial keratitis will be recruited. |
Who may qualify
- Ages
- 16 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Study participants with suspected microbial keratitis will be recruited and consented at their first presentation at the Ophthalmology Acute Referral Clinic, or on-call service at the Princess Alexandra Eye Pavilion, Edinburgh, UK. Healthy control volunteer participants will be recruited from the University of Edinburgh by email invitation or by word-of-mouth
Key inclusion criteria (4 listed)
- 16 years old or older.
- Able to provide informed consent for themselves.
- Patient group: Appearances typical of a new infective keratitis of the cornea, in one eye only.
- Control group: healthy volunteers with no recent history (within 1 year) of MK or inflammatory eye condition.
Key exclusion criteria (5 listed)
- <16 years old.
- Not able to provide consent for themselves.
- Patients with suspected viral rather than bacterial/fungal corneal infection, such as herpetic keratitis.
- Patients who present with MK in both eyes.
- Control group: Individuals receiving topical steroid or antimicrobial therapy to the eye, or any other form of systemic immunosuppression/antimicrobial drug.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Globally measure, list and compare the peptides extracted from ocular tear samples of participants with and without the disease (microbial keratitis) throughout the infection course.
Time frame: 5 years
Identify any proteomic signatures of disease prognosis
Globally measure, list and compare the metabolites extracted from ocular tear samples of participants with and without the disease (microbial keratitis) throughout the infection course.
Time frame: 5 years
Identify any metabolomic signatures of disease prognosis
1 secondary outcome
Measure, list and compare microorganisms (bacteria and fungi) extracted from ocular swab samples of participants with and without the disease (microbial keratitis)
Time frame: 5 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Aug 2025.
- Individual participant dataSharing planned: Undecided
Related trials for Microbial Keratitis
Not yet recruitingObservational study
Pattern of Microbial Keratitis in Assiut University Hospital
Keratitis, Microbial Keratitis
RecruitingObservational study
Use of a New Method for the Microbiological Diagnosis of Severe Corneal Infection
Infectious Keratitis, Microbial Keratitis
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Naing Latt Tint, FRCOphth principal investigator
NHS Lothian
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Microbial Keratitis, run by University of Edinburgh at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 26 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Globally measure, list and compare the peptides extracted from ocular tear samples of participants with and without the disease (microbial keratitis) throughout the infection course. (time frame: 5 years). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Aug 2025; AzTrials last refreshed its copy on 31 Oct 2026.