Controlled Adverse Environment: A Pilot Study to Evaluate Tear Film Stability and Tear Evaporation

NCT ID: NCT01448356

Last Updated: 2012-12-12

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2012-01-31
• Study Completion Date: 2012-04-30

Brief 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. 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:

1. A primary purpose of the study is to evaluate fluorescein tear break up times in participants under different humidity/ temperature conditions.

2. 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

Keywords

Controlled adverse chamber; tear film stability; tear film evaporation; tear film break up time; humidity; temperature

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

temperature and humidity

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

Group Type: EXPERIMENTAL

temperature and humidity

Intervention Type: PROCEDURE

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

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.

Interventions

temperature and humidity

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

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.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• must have undergone screening examination

Exclusion Criteria

• unable to go to the DSO laboratory or undergo any of the study procedures

• Minimum Eligible Age: 21 Years
• Maximum Eligible Age: 90 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Singapore National Eye Centre

OTHER_GOV

Sponsor Role: collaborator

Singapore Eye Research Institute

OTHER

Sponsor Role: lead

Responsible Party

Andrea Petznick, PhD

Postdoctoral Research Fellow

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Andrea Petznick, PhD

Role: PRINCIPAL_INVESTIGATOR

Singapore Eye Research Institute

Locations

Singapore Eye Research Institute

Singapore, Singapore, Singapore

Countries

Singapore

References

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.

Reference Type: BACKGROUND

PMID: 17724183 (View on PubMed)

Wolkoff 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.

Reference Type: BACKGROUND

PMID: 20833234 (View on PubMed)

Other Identifiers

2011/197/A

Identifier Type: OTHER

Identifier Source: secondary_id

R857/52/2011

Identifier Type: -

Identifier Source: org_study_id