Technical difficulties have been reported by some users of the search function and is being investigated by technical staff. Thank you for your patience and apologies for any inconvenience caused.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12619001290189
Ethics application status
Approved
Date submitted
4/09/2019
Date registered
19/09/2019
Date last updated
28/06/2022
Date data sharing statement initially provided
19/09/2019
Date results information initially provided
28/06/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
Diurnal variations of melatonin and ocular parameters in healthy young adults
Scientific title
Melatonin concentration and ocular biometric rhythms in adults
Secondary ID [1] 299091 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Myopia 314132 0
Condition category
Condition code
Eye 312506 312506 0 0
Diseases / disorders of the eye

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
This is an observational study and no intervention will be given to participants.
A screening will be arranged for participants who expressed interest in order to determine their ocular health and eligibility for this study. The screening will take about 30 minutes. Participants who are not suitable will be excluded. Clinic visit appointments will be scheduled for participants who are eligible to participate.
On the testing day, participants will attend 7 visits (up to 30 minutes per visit) over 24 hours. During the night time (from 8pm to 8am on the following day), participants will be asked to remain in the clinic as a safety precaution. Participants will each have their own room and will be encouraged to sleep during the night.
Intervention code [1] 315437 0
Not applicable
Comparator / control treatment
This is an observational study, no intervention will be given to participants.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 321241 0
Diurnal variations of axial length measured by LenStar.
Timepoint [1] 321241 0
Seven visits over 24 hours with a frequency of one visit every 4 hours.
Primary outcome [2] 321351 0
Diurnal variations of saliva melatonin concentration quantified by ELISA.
Timepoint [2] 321351 0
Seven visits over 24 hours with a frequency of one visit every 4 hours.
Secondary outcome [1] 374439 0
Diurnal variations of choroidal thickness measured by OCT.
Timepoint [1] 374439 0
Seven visits over 24 hours with a frequency of one visit every 4 hours.
Secondary outcome [2] 374714 0
Diurnal variations of pupil response (pupil diameter changes in mm) to 1-second blue or red light will be recorded as video using commercial eye-tracker and then analysed with Matlab or R.
Timepoint [2] 374714 0
Seven visits over 24 hours with a frequency of one visit every 4 hours.
Secondary outcome [3] 374715 0
Diurnal variations of light exposure measured by a wearable light logger.
Timepoint [3] 374715 0
Light intensity will be recorded with a frequency of up to one measurement every 30 seconds during the whole study period (24 hours).

Eligibility
Key inclusion criteria
• Adults with good general health, age range 18 to 35 years
• Best-corrected visual acuity of 20/20 or better in each eye, with or without refractive error
• Have ocular health findings considered to be ‘normal’ (E.g. no ocular diseases or history of eye surgery)
• Willing to sign informed consent and comply with study schedule
• Willing to stay in the clinic for overnight measurements
Minimum age
18 Years
Maximum age
35 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
• Current smokers
• Pregnant women
• Colour vision deficiency
• Intraocular pressure > 21 mmHg
• Anterior and posterior ocular anomalies
• Unusual pupil findings, including relative afferent pupil defect (RAPD), anisocoria, mydriasis or miosis, etc.
• Systemic diseases that may affect ocular health (e.g. hypertension, diabetes mellitus, etc.)
• Use of or a need for any systemic medication or topical medications which may alter normal ocular findings / are known to affect a participant’s ocular health / physiology either in an adverse or beneficial manner
• Use of or a need for any systemic medication or topical medications which may / are known to affect the pupil light response (e.g. psychiatric medications)
• Use of myopia control medications or devices
• Use of melatonin or any pharmacological sleep aids
• Experienced jet lag within one month before participating in the study

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Defined population
Timing
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 28249 0
2052 - Unsw Sydney

Funding & Sponsors
Funding source category [1] 303627 0
Other Collaborative groups
Name [1] 303627 0
Brien Holden Vision Institute Limited
Country [1] 303627 0
Australia
Primary sponsor type
Other Collaborative groups
Name
Brien Holden Vision Institute Limited
Address
Level 5, North Wing, Rupert Myers Building, Gate 14, Barker Street UNSW SYDNEY NSW 2052
Country
Australia
Secondary sponsor category [1] 303719 0
None
Name [1] 303719 0
Address [1] 303719 0
Country [1] 303719 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 304153 0
HREC Executive, UNSW
Ethics committee address [1] 304153 0
Level 3, Rupert Myers Building (South Wing), Gate 14, Barker Street UNSW, Sydney, NSW 2052.
Ethics committee country [1] 304153 0
Australia
Date submitted for ethics approval [1] 304153 0
19/04/2019
Approval date [1] 304153 0
01/07/2019
Ethics approval number [1] 304153 0
HC190305

Summary
Brief summary
Globally, by 2050, every one in two people will be myopic. It is in fact a vision-threatening public health issue. Interestingly, it has been found that there is seasonal variation in ocular growth with less growth during summer months. Additionally, ocular parameters such as eye length have also been reported to exhibit a diurnal rhythm. This observational study aims to investigate variations in ocular parameters over 24 hours and to evaluate their associations with the body clock and daily light exposure among healthy young adults.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 95982 0
Prof Padmaja Sankaridurg
Address 95982 0
Level 4, North Wing, Rupert Myers Building, Gate 14, Barker Street UNSW SYDNEY NSW 2052
Country 95982 0
Australia
Phone 95982 0
+61 02 93857485
Fax 95982 0
Email 95982 0
p.sankaridurg@brienholdenvision.org
Contact person for public queries
Name 95983 0
Prof Padmaja Sankaridurg
Address 95983 0
Level 4, North Wing, Rupert Myers Building, Gate 14, Barker Street UNSW SYDNEY NSW 2052
Country 95983 0
Australia
Phone 95983 0
+61 02 93857485
Fax 95983 0
Email 95983 0
p.sankaridurg@brienholdenvision.org
Contact person for scientific queries
Name 95984 0
Prof Padmaja Sankaridurg
Address 95984 0
Level 4, North Wing, Rupert Myers Building, Gate 14, Barker Street UNSW SYDNEY NSW 2052
Country 95984 0
Australia
Phone 95984 0
+61 02 93857485
Fax 95984 0
Email 95984 0
p.sankaridurg@brienholdenvision.org

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
To protect the identity of the participant.


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.