Twice-Daily Systane Complete Versus Four-Times-Daily Thealoz Duo for Dry Eye Disease

July 23, 2026 updated by: Jose Navarro Partida, Instituto Internacional de Medicina y Terapia (IIMET)

Twice-Daily Systane Complete Versus Four-Times-Daily Thealoz Duo for Dry Eye Disease: A Randomized Controlled Non-Inferiority Trial

The goal of this clinical trial is to learn whether a twice-daily dosing schedule of Systane Complete eye drops works as well as a four-times-daily dosing schedule of Thealoz Duo eye drops to treat dry eye disease in adults. The main questions it aims to answer are:

  • Does twice-daily Systane Complete provide similar improvement in dry eye symptoms, measured by the Ocular Surface Disease Index (OSDI), compared with four-times-daily Thealoz Duo after 30 days of treatment?
  • How do the treatments affect tear film stability, tear production, and damage to the surface of the eye?

Researchers will compare Systane Complete (used twice a day) to Thealoz Duo (used four times a day) to see if the simpler dosing schedule maintains similar benefits for symptoms and eye surface health.

Participants will be adults with mild to moderate dry eye disease who are seen in an outpatient eye clinic. They will be randomly assigned to one of the two treatment groups. All participants will use their assigned eye drops in both eyes for 30 days and will attend clinic visits at the start of the study and after 30 days. At each visit, participants will complete the OSDI questionnaire and undergo standard eye tests, including tear break-up time, Schirmer test, and grading of surface staining on the eye.

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.

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.
120

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

  • Mexico
    • Jalisco
      • Zapopan, Jalisco, Mexico
        • Hospital Puerta de Hierro

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:

  • Adults (≥18 years of age) with mild to moderate dry eye disease (DED).
  • Ocular Surface Disease Index (OSDI) score between 13 and 32 at baseline.

  • At least one abnormal objective test of ocular surface dysfunction, defined as one or more of the following:

    • Schirmer test result < 10 mm in 5 minutes (without anesthesia), or
    • Tear break-up time (TBUT) < 10 seconds, or
    • Ocular surface staining graded between stages 1 and 3 according to the Oxford scale.
  • Best-corrected visual acuity of 20/200 or better in both eyes.
  • Able to provide written informed consent and comply with study procedures and scheduled visits.

Exclusion Criteria:

  • Pregnancy or breastfeeding.
  • Participation in another clinical trial or prior participation in the present study.
  • Best-corrected visual acuity worse than 20/200 in either eye.
  • Active ocular disease including conjunctivitis, blepharitis, keratitis, ocular trauma, ocular surface scarring, corneal ulcers, neurotrophic keratitis, bullous keratopathy, or neoplastic disease of the ocular surface.
  • Glaucoma or eyelid disorders that affect normal eyelid function.
  • Advanced dry eye disease requiring second-line TFOS DEWS II therapy.
  • Ocular surgery within the previous 3 months.
  • Contact lens use within 15 days prior to enrollment.
  • Known hypersensitivity to any component of the study medications.
  • Substance dependence within the previous 2 years.
  • Systemic conditions that could increase the risk of study participation or interfere with interpretation of study outcomes, as judged by the investigators.
  • Women of childbearing potential not using stable contraceptive methods for at least 30 days prior to enrollment and throughout the study duration.

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: None (Open Label)

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: Systane Complete twice daily
Participants in this arm will instill one to two drops of Systane Complete in each eye twice daily for 30 days. They will be instructed to maintain a minimum interval of eight hours between doses and to avoid using additional topical ophthalmic medications during the study period unless clinically necessary and documented by investigators.
Drug: Systane Complete
Systane Complete is a commercially available lipid-containing artificial tear formulation that combines mineral oils with nano-droplet lipid technology to support all three layers of the tear film (lipid, aqueous, and mucin). In this study, participants assigned to this intervention will instill one to two drops in each eye twice daily for 30 days, maintaining a minimum interval of eight hours between doses and avoiding additional topical ophthalmic medications during the study period unless clinically necessary and documented by investigators.
Other Names:
  • Lipid-containing artificial tears
Active Comparator: Thealoz Duo four times daily
Participants in this arm will instill one to two drops of Thealoz Duo in each eye four times daily for 30 days. They will be instructed to maintain a minimum interval of four hours between doses and to avoid using additional topical ophthalmic medications during the study period unless clinically necessary and documented by investigators.
Drug: Thealoz Duo
Thealoz Duo is a commercially available ophthalmic solution that combines hyaluronic acid with trehalose to protect the ocular surface and support epithelial recovery in dry eye disease. In this study, participants assigned to this intervention will instill one to two drops in each eye four times daily for 30 days, maintaining a minimum interval of four hours between doses and avoiding additional topical ophthalmic medications during the study period unless clinically necessary and documented by investigators.
Other Names:
  • Hyaluronic acid and trehalose ophthalmic solution

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
Change in Ocular Surface Disease Index (OSDI) score from baseline to day 30
Time Frame: From baseline (day 0) to day 30 of treatment
The Ocular Surface Disease Index (OSDI) is a validated 12-item questionnaire that measures the frequency of dry eye symptoms and their impact on visual function and daily activities. Scores range from 0 to 100, with higher scores indicating more severe symptoms. In this trial, participants complete the OSDI at baseline and after 30 days of treatment. The primary outcome is the adjusted mean OSDI score at day 30, analyzed using analysis of covariance (ANCOVA) with baseline OSDI as a covariate to compare twice-daily Systane Complete with four-times-daily Thealoz Duo within a non-inferiority framework.
From baseline (day 0) to day 30 of treatment

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
Change in tear break-up time (TBUT) from baseline to day 30
Time Frame: Baseline and day 30 after start of treatment
Tear break-up time (TBUT) is measured using fluorescein dye as the interval in seconds between a complete blink and the first appearance of a discontinuity in the tear film. TBUT is assessed in both eyes at baseline and at day 30 under controlled environmental conditions; values from the right and left eyes are averaged to obtain a single patient-level value. The secondary outcome is the change in mean TBUT (seconds) from baseline to day 30 and the between-group comparison of TBUT at day 30.
Baseline and day 30 after start of treatment
Change in Schirmer test value from baseline to day 30
Time Frame: Baseline and day 30 after start of treatment
Schirmer test without anesthesia is used to assess tear production by placing filter paper strips in the lower eyelid for 5 minutes and measuring the length of wetting in millimeters. Schirmer test is performed in both eyes at baseline and at day 30; measurements from right and left eyes are averaged to generate a single patient-level value. The secondary outcome is the change in mean Schirmer test value (millimeters) from baseline to day 30 and the between-group comparison of Schirmer values at day 30.
Baseline and day 30 after start of treatment
Treatment adherence over 30 days of follow-up
Time Frame: Day 15 and day 30 of treatment
Treatment adherence is evaluated using patient-completed daily treatment diaries that record each administration of the assigned study medication. Adherence (%) is calculated using the formula AD = (RA × 100) / IA, where RA is the number of recorded administrations and IA is the total number of indicated applications according to the prescribed dosing regimen. Adherence is assessed at day 15 and day 30. Participants with adherence values below 90% are considered to have protocol deviations and are excluded from the per-protocol analysis.
Day 15 and day 30 of treatment
Change in Oxford corneal and conjunctival staining score from baseline to day 30
Time Frame: Baseline and day 30 after start of treatment
Corneal and conjunctival epithelial staining is evaluated using fluorescein and graded according to the Oxford grading scale for ocular surface staining. The Oxford scale ranges from grade 0 (no staining) to grade 5 (severe staining), with higher grades indicating more extensive epithelial damage. Staining is assessed in both eyes at baseline and at day 30; scores from the right and left eyes are averaged to obtain a single patient-level value. The secondary outcome includes the change in mean Oxford staining score from baseline to day 30 and the proportion of participants achieving complete resolution of corneal staining (Oxford grade 0) at day 30 in each treatment group.
Baseline and day 30 after start of treatment

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.
Instituto Internacional de Medicina y Terapia (IIMET)

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Centro de Retina Médica y Quirúrgica S.C.
Hospital Puerta de Hierro, Zapopan

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Dalia Denisse Ng-Aleman, MD, Hospital Puerta de Hierro

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.
January 6, 2025

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.
June 30, 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 30, 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).
July 19, 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.
July 19, 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.
July 23, 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.
July 24, 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.
July 23, 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.
July 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.
  • HPH-DED-SYS-2026-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The datasets generated and analysed during the current study are not publicly available due to institutional and patient privacy restrictions, but are available from the corresponding author on reasonable request.

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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