Environmental ExposureNCT01448356
Controlled Adverse Environment: A Pilot Study to Evaluate Tear Film Stability and Tear Evaporation
A study testing temperature and humidity in people with Environmental Exposure, run by Singapore Eye Research Institute at 1 site in Singapore.
Trial summary
Dry eye and ocular surface disease account for a lot of morbidity and socio-economic burden in Asia and the rest of the world. This is a small pilot study to evaluate tear function under different conditions of humidity and temperature. Read more about this study
- Who is it for?
- Ages 21 to 90 yearsHealthy volunteers can take part
- Conditions the study is for
- Environmental Exposure
- What is being tested?
- temperature and humidity
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- 1 siteSingapore
- Study dates
- Jan 2012to Apr 2012
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 21 to 90 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- must have undergone screening examination
Who cannot join
- unable to go to the DSO laboratory or undergo any of the study procedures
Trial locations and contacts
1 site in 1 country.
Singapore1 site
Singapore Eye Research Institute
Singapore, Singapore, 168751
About this study
Dry eye and ocular surface disease account for a lot of morbidity and socio-economic burden in Asia and the rest of the world. This is a small pilot study to evaluate tear function under different conditions of humidity and temperature. This data will be useful for designing future trials in ocular surface and dry eye. The data will likely be used to propose a larger national funded project involving clinical trials. This study involves collaboration between engineers, ocular surface clinicians as well as specialists from the defence science organisation. When successfully completed, the project will increase the capability of Singapore Eye Research Institute and Singapore National Eye Centre to support future industry and academic research in the ocular surface.
Read the detailed description
Study Objectives and Purpose:
- A primary purpose of the study is to evaluate fluorescein tear break up times in participants under different humidity/ temperature conditions.
- The second aim is to assess the tear evaporation rates in a dynamic fashion over 20 seconds (based on a non-invasive ocular thermography method) after exposure to different humidity/temperature conditions.
Study Design: Prospective, non-comparative, clinical study
Rationale:
The ocular surface research team who is based at the dry eye service of the Singapore National Eye Center is experienced in the assessment of the ocular surface in patients and clinical trial participants. Collaborators from the DSO National laboratory already have experience in conducting human studies in a controlled environment in Singapore that has been proven to be safe and has passed necessary regulatory approval. In addition, recent technological advances have allowed collaborators from NTU and Singapore Polytechnic to perform non-invasive tear evaporimetry in a dynamic way between blinks. Together, this is a strong research team that can address the important question of the influence of temperature and humidity on the tear film stability.
Methods:
We intend to use 10 volunteer/patients to establish whether tear film stability or tear film function can be altered after exposure to different combinations of humidity and temperature. This involves the assessment of tear film break up time (TBUT) and tear evaporimetry, a non-invasive procedure (like an auto-refractor where the patient places the chin on the chin rest and forehead on the head rest when the measurement is taken) which involves taking serial images with an infra red sensitive video camera. This process is performed at a facility which is closely monitored and proven to be safe for other research participants.
Participants and target sample size: Ten participants will be recruited.
Workflow:
We assume that approximately 45 minutes are required for the chamber to achieve the required temperature and humidity, and about 15 to 20 minutes for participants to adjust to the first environmental setting. Thermography measurement will take 1 minute (20 sec in each eye, with adjustment of camera between eyes). The participants will undergo slit lamp examination where the fluorescein tear break up time will be assessed and digital color image of the break up pattern will be taken. These will require a further 5 minutes. This means 3 participants can have measurements done in approximately 20 minutes. Measurements of 3 participants in a single condition will therefore take up to 20 minutes.In a session that will last up to 3 hours and 20 minutes, the investigators can complete the condition list for 3 participants. Since the overall session is quite long, a toilet break is permitted after each temperature condition.
The investigators estimate that 3 sessions with a further 'dry run' for the photography (without participants) before the first session will be necessary.
Visit schedules:
Volunteers or patients from the Singapore National Eye Center will be informed of this study. Screening will be performed at the regular dry eye clinic at the Singapore National Eye Center. If eligible, the volunteer or patient will sign consent and undergo baseline examination. Subsequent to this, the examination will be performed at the controlled adverse environment at the DSO facility.
Assessment of ocular parameters is outlined below:
At Screening visit, the investigators perform:
- Informed consent
- Subject background
- Anterior segment findings
- Tear film break up time
At Evaluation visit, the investigators perform:
- Tear film break up time
- Photography/Video to document tear break up
- Tear evaporimetry
Duration of study: Four weeks.
- Conditions
- Environmental Exposure
- Being tested
- temperature and humidity
- Keywords
- Controlled adverse chamber, tear film stability, tear film evaporation, tear film break up time, humidity, temperature
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
temperature and humidityProcedure or surgery
The volunteer is exposed to a controlled environment with a chamber setting of:
- 25°C and 45% humidity;
- 25°C and 65% humidity;
- 30°C and 45% humidity;
- 30°C and 65% humidity
After an adaptation period of at least 20 minutes, participants underwent measurements of tear evaporation and tear film break up time. After collection of data, the chamber settings were adjusted to the next condition.
| Study group | Role | What they receive |
|---|---|---|
| temperature and humidity | Experimental | The volunteer is exposed to a controlled environment with a chamber setting of:
1. 25°C and 45% humidity;
2. 25°C and 65% humidity;
3. 30°C and 45% humidity;
4. 30°C and 65% humidity Receives: Procedure: temperature and humidity |
What is being measured
The primary outcome is the main question the study is designed to answer.
Tear Evaporation Rate
The rate of tear evaporation is measured by the use of ocular thermography. For each subject,his/her ocular surface temperature will be recorded twice, one for each eye. The subject at first rests his/her chin on a chin rest, with his/her forehead lean against a metal frame (which is part of the chin rest). Then the recording starts lasting approximately 20seconds for each eye. While recording, the subject needs to look straight into the lens, but can blink naturally. After this, the recording data will be analyzed to derive the evaporation rate using a mathematical model.
Measured: 20 minutes after the required temperature and humidity in the chamber is achieved
Secondary outcomes (1)
Tear Film Break up Time
After instillation of fluorescein, the participant will then be asked to open the eyes, look ahead at the observer's forehead and not blink for as long as possible. The break up time is defined as the time between the lid opening and the first appearance of any dry spot on the cornea. The participant will be requested to close his eyes for few seconds and the procedure will be repeated for the left eye.
Measured: 20 minutes after the required temperature and humidity in the chamber is achieved
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Oct 2011 (estimated)
- Study startJan 2012
- Primary completionApr 2012
- Study completionApr 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Environmental ExposureStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 10 participants (actual)
Sponsor and investigators
- Lead sponsor
- Singapore Eye Research Institute
- Sponsor type
- University, hospital or other
- Collaborators
- Singapore National Eye Centre
- Responsible party
- Principal investigator, Andrea Petznick, PhD, Singapore Eye Research Institute
- Investigators
- Andrea Petznick, PhD, Principal investigator, Singapore Eye Research Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01448356
- Sponsor's protocol ID
- R857/52/2011
- Other IDs
- 2011/197/A
- Status last verified
- Nov 2012
- First submitted
- 4 Oct 2011
- Last updated
- 12 Dec 2012
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Publications
Gonzalez-Garcia MJ, Gonzalez-Saiz A, de la Fuente B, Morilla-Grasa A, Mayo-Iscar A, San-Jose J, Feijo J, Stern ME, Calonge M. Exposure to a controlled adverse environment impairs the ocular surface of subjects with minimally symptomatic dry eye. Invest Ophthalmol Vis Sci. 2007 Sep;48(9):4026-32. doi: 10.1167/iovs.06-0817.
PubMed 17724183Wolkoff P. Ocular discomfort by environmental and personal risk factors altering the precorneal tear film. Toxicol Lett. 2010 Dec 15;199(3):203-12. doi: 10.1016/j.toxlet.2010.09.001. Epub 2010 Sep 15.
PubMed 20833234
Study at a glance
From the registry record, last updated by the sponsor on 12 Dec 2012. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Controlled Adverse Environment: A Pilot Study to Evaluate Tear Film Stability and Tear Evaporation
- ClinicalTrials.gov ID
- NCT01448356
- Acronym / sponsor ID
- R857/52/2011
- Conditions
- Environmental Exposure
- Keywords
- Controlled adverse chamber, tear film stability, tear film evaporation, tear film break up time, humidity, temperature
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 10 participants (actual)
- Lead sponsor
- Singapore Eye Research InstituteUniversity, hospital or other
- Collaborators
- Singapore National Eye Centre
- Study start
- Jan 2012
- Primary completion
- Apr 2012 (actual)
- Study completion
- Apr 2012 (actual)
- First posted
- 7 Oct 2011 (estimated)
- Results
- Posted 12 Dec 2012
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Dry eye and ocular surface disease account for a lot of morbidity and socio-economic burden in Asia and the rest of the world. This is a small pilot study to evaluate tear function under different conditions of humidity and temperature. This data will be useful for designing future trials in ocular surface and dry eye. The data will likely be used to propose a larger national funded project involving clinical trials. This study involves collaboration between engineers, ocular surface clinicians as well as specialists from the defence science organisation. When successfully completed, the project will increase the capability of Singapore Eye Research Institute and Singapore National Eye Centre to support future industry and academic research in the ocular surface.
Detailed description
Study Objectives and Purpose:
- A primary purpose of the study is to evaluate fluorescein tear break up times in participants under different humidity/ temperature conditions.
- The second aim is to assess the tear evaporation rates in a dynamic fashion over 20 seconds (based on a non-invasive ocular thermography method) after exposure to different humidity/temperature conditions.
Study Design: Prospective, non-comparative, clinical study
Rationale:
The ocular surface research team who is based at the dry eye service of the Singapore National Eye Center is experienced in the assessment of the ocular surface in patients and clinical trial participants. Collaborators from the DSO National laboratory already have experience in conducting human studies in a controlled environment in Singapore that has been proven to be safe and has passed necessary regulatory approval. In addition, recent technological advances have allowed collaborators from NTU and Singapore Polytechnic to perform non-invasive tear evaporimetry in a dynamic way between blinks. Together, this is a strong research team that can address the important question of the influence of temperature and humidity on the tear film stability.
Methods:
We intend to use 10 volunteer/patients to establish whether tear film stability or tear film function can be altered after exposure to different combinations of humidity and temperature. This involves the assessment of tear film break up time (TBUT) and tear evaporimetry, a non-invasive procedure (like an auto-refractor where the patient places the chin on the chin rest and forehead on the head rest when the measurement is taken) which involves taking serial images with an infra red sensitive video camera. This process is performed at a facility which is closely monitored and proven to be safe for other research participants.
Participants and target sample size: Ten participants will be recruited.
Workflow:
We assume that approximately 45 minutes are required for the chamber to achieve the required temperature and humidity, and about 15 to 20 minutes for participants to adjust to the first environmental setting. Thermography measurement will take 1 minute (20 sec in each eye, with adjustment of camera between eyes). The participants will undergo slit lamp examination where the fluorescein tear break up time will be assessed and digital color image of the break up pattern will be taken. These will require a further 5 minutes. This means 3 participants can have measurements done in approximately 20 minutes. Measurements of 3 participants in a single condition will therefore take up to 20 minutes.In a session that will last up to 3 hours and 20 minutes, the investigators can complete the condition list for 3 participants. Since the overall session is quite long, a toilet break is permitted after each temperature condition.
The investigators estimate that 3 sessions with a further 'dry run' for the photography (without participants) before the first session will be necessary.
Visit schedules:
Volunteers or patients from the Singapore National Eye Center will be informed of this study. Screening will be performed at the regular dry eye clinic at the Singapore National Eye Center. If eligible, the volunteer or patient will sign consent and undergo baseline examination. Subsequent to this, the examination will be performed at the controlled adverse environment at the DSO facility.
Assessment of ocular parameters is outlined below:
At Screening visit, the investigators perform:
- Informed consent
- Subject background
- Anterior segment findings
- Tear film break up time
At Evaluation visit, the investigators perform:
- Tear film break up time
- Photography/Video to document tear break up
- Tear evaporimetry
Duration of study: Four weeks.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| temperature and humidity | Experimental | Procedure: temperature and humidityThe volunteer is exposed to a controlled environment with a chamber setting of: 1. 25°C and 45% humidity; 2. 25°C and 65% humidity; 3. 30°C and 45% humidity; 4. 30°C and 65% humidity |
Who may qualify
- Ages
- 21 to 90 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- must have undergone screening examination
Key exclusion criteria (1 listed)
- unable to go to the DSO laboratory or undergo any of the study procedures
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| temperature and humidityThe volunteer is exposed to a controlled environment with a chamber setting of: 1. 25°C and 45% humidity; 2. 25°C and 65% humidity; 3. 30°C and 45% humidity; 4. 30°C and 65% humidity After an adaptation period of at least 20 minutes, participants underwent measurements of tear evaporation and tear film break up time. After collection of data, the chamber settings were adjusted to the next condition. | Procedure or surgery | temperature and humidity |
Primary outcome
Tear Evaporation Rate
Time frame: 20 minutes after the required temperature and humidity in the chamber is achieved
The rate of tear evaporation is measured by the use of ocular thermography. For each subject,his/her ocular surface temperature will be recorded twice, one for each eye. The subject at first rests his/her chin on a chin rest, with his/her forehead lean against a metal frame (which is part of the chin rest). Then the recording starts lasting approximately 20seconds for each eye. While recording, the subject needs to look straight into the lens, but can blink naturally. After this, the recording data will be analyzed to derive the evaporation rate using a mathematical model.
1 secondary outcome
Tear Film Break up Time
Time frame: 20 minutes after the required temperature and humidity in the chamber is achieved
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Dec 2012.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 17724183Gonzalez-Garcia MJ, Gonzalez-Saiz A, de la Fuente B, Morilla-Grasa A, Mayo-Iscar A, San-Jose J, Feijo J, Stern ME, Calonge M. Exposure to a controlled adverse environment impairs the ocular surface of subjects with minimally symptomatic dry eye. Invest Ophthalmol Vis Sci. 2007 Sep;48(9):4026-32. doi: 10.1167/iovs.06-0817.
- Background: PubMed 20833234Wolkoff P. Ocular discomfort by environmental and personal risk factors altering the precorneal tear film. Toxicol Lett. 2010 Dec 15;199(3):203-12. doi: 10.1016/j.toxlet.2010.09.001. Epub 2010 Sep 15.
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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.
Andrea Petznick, PhD principal investigator
Singapore Eye Research Institute
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing temperature and humidity in people with Environmental Exposure, run by Singapore Eye Research Institute at 1 site in Singapore.
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 1 inclusion and 1 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 12 Dec 2012. 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 Singapore. 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?
Yes. Results are posted in the registry (first posted 12 Dec 2012). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Tear Evaporation Rate (time frame: 20 minutes after the required temperature and humidity in the chamber is achieved). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01448356, which also lists 2 linked publications.
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 12 Dec 2012.