Effect of an Eye Mask-Based Blackout Protocol on Sleep Quality and Melatonin

January 29, 2026 updated by: Bahar Ciftci, Ataturk University

The Effect of an Eye Mask-Based Blackout Protocol on Patients' Sleep Quality and Melatonin Levels: A Randomised Controlled Trial

Sleep disturbance is a common problem among patients hospitalized in intensive care units due to continuous light exposure, noise, and frequent medical interventions. Disruption of the normal day-night cycle may reduce melatonin secretion and negatively affect sleep quality and recovery.

This randomized controlled study aimed to evaluate the effect of an eye mask-based blackout protocol on sleep quality and melatonin levels in patients hospitalized in a chest intensive care unit. Participants were randomly assigned to either an intervention group or a control group. Patients in the intervention group wore a lightproof eye mask during nighttime hours (11:00 p.m. to 05:00 a.m.) in addition to standard light-reduction practices, while the control group received routine intensive care.

Sleep quality was assessed using validated subjective scales, and melatonin levels were evaluated by measuring urinary 6-sulfatoxymelatonin. The study sought to determine whether reducing nighttime light exposure using a simple, non-invasive intervention could improve sleep quality and support circadian rhythm regulation in intensive care patients.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study was designed as a randomized controlled trial to investigate the effect of an eye mask-based blackout protocol on sleep quality and melatonin levels in patients hospitalized in a chest intensive care unit.

The study was conducted at a university research hospital in Turkey. Eligible adult patients who were conscious, breathing spontaneously, and able to provide informed consent were randomly assigned to either an intervention group or a control group using a 1:1 allocation ratio. Patients receiving mechanical ventilation or using medications affecting melatonin secretion were excluded.

Participants in the intervention group wore a lightproof eye mask between 11:00 p.m. and 05:00 a.m. for two consecutive nights. In addition to eye mask use, nighttime lighting in the patient's room was minimized according to a standardized protocol. The control group received routine intensive care without any additional light-reduction intervention.

Sleep quality was evaluated using the Visual Analogue Scale for Sleep Quality and the Richard Campbell Sleep Scale. Melatonin secretion was assessed by measuring urinary 6-sulfatoxymelatonin levels collected overnight. Urine samples were stored under controlled conditions and analyzed using an enzyme-linked immunosorbent assay (ELISA).

The primary objective of the study was to determine whether the eye mask-based blackout protocol improved subjective sleep quality. A secondary objective was to assess changes in melatonin levels as a biological marker of circadian rhythm regulation.

All procedures were conducted in accordance with the Declaration of Helsinki. Ethical approval was obtained from the relevant institutional ethics committee, and written informed consent was obtained from all participants prior to enrollment.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
60

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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

  • Turkey (Türkiye)
    • Erzurum
      • Erzurum, Erzurum, Turkey (Türkiye), 25000
        • Atatürk University Faculty of Nursing

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adult patients aged 18 years and older
  • Patients admitted to the intensive care unit
  • Patients expected to remain in the intensive care unit for at least 24 hours
  • Patients with the ability to tolerate an eye mask during nighttime sleep
  • Patients or their legal representatives who provided informed consent

Exclusion Criteria:

  • Patients with facial trauma, eye injury, or ophthalmologic conditions preventing eye mask use
  • Patients receiving continuous deep sedation
  • Patients with severe cognitive impairment or delirium preventing cooperation
  • Patients with diagnosed sleep disorders prior to intensive care admission
  • Patients who refused to participate in the study

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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Eye Mask Intervention Group
Participants received a nighttime eye mask-based blackout protocol during sleep hours in the intensive care unit in addition to routine care.
Other: Eye Mask-Based Blackout Protocol
A non-pharmacological nursing intervention involving the use of an eye mask during nighttime sleep to reduce light exposure and support circadian rhythm regulation in intensive care unit patients.
No Intervention: Control Group
Participants received routine intensive care without the use of an eye mask.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Sleep quality (Richard-Campbell Sleep Questionnaire [RCSQ] total score)
Time Frame: Measured twice: (1) baseline-morning of ICU day 2 (after the first night, 23:00-05:00), and (2) post-intervention-morning of ICU day 3 (after the blackout night with eye mask from 23:00 to 05:00).
Change in sleep quality assessed using the Richard-Campbell Sleep Questionnaire (6 items, 0-100 VAS each; higher scores indicate better sleep). The total score is calculated as the mean of all item scores.
Measured twice: (1) baseline-morning of ICU day 2 (after the first night, 23:00-05:00), and (2) post-intervention-morning of ICU day 3 (after the blackout night with eye mask from 23:00 to 05:00).

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Sleep quality (Visual Analogue Scale [VAS], 1-10)
Time Frame: Measured twice: (1) baseline-morning of ICU day 2 (after the first night, 23:00-05:00), and (2) post-intervention-morning of ICU day 3 (after the blackout night with eye mask from 23:00 to 05:00).
Self-reported sleep quality rated on a 1-10 scale (1 = worst sleep quality, 10 = best sleep quality).
Measured twice: (1) baseline-morning of ICU day 2 (after the first night, 23:00-05:00), and (2) post-intervention-morning of ICU day 3 (after the blackout night with eye mask from 23:00 to 05:00).
Urinary 6-sulfatoxymelatonin (aMT6s) level (ng/mg creatinine)
Time Frame: Measured twice using overnight urine collection: (1) baseline-urine accumulated from 23:00 to 05:00 on the first night (ICU day 2 morning sample), and (2) post-intervention-urine accumulated from 23:00 to 05:00 on the blackout night with eye mask (ICU da
Change in melatonin secretion assessed by urinary 6-sulfatoxymelatonin (aMT6s) measured by ELISA and normalized to urinary creatinine (ng/mg creatinine). Urine was collected via Foley catheter drainage.
Measured twice using overnight urine collection: (1) baseline-urine accumulated from 23:00 to 05:00 on the first night (ICU day 2 morning sample), and (2) post-intervention-urine accumulated from 23:00 to 05:00 on the blackout night with eye mask (ICU da

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Ataturk University

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 20, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 29, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 4, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 4, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 29, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ATAUNI-SLEEP-ICU-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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