Comparison of 4 Methods of Eye Drops for Pupil Dilation in Diabetic Patients

March 24, 2026 updated by: Nattawat Asawaworarit, Burapha University

Comparison of Mydriatic Effects Between 4 Regimens of a Tropicamide-Phenylephrine Combination in Diabetic Patients

Pupil dilation is required for many eye conditions. Diabetic patients may need more dilating eye drops to have pupil size large enough for eye exams. This study compares 4 methods of eye drops for pupil dilation in diabetic patients scheduled for retinopathy screening. Possible side effects of the eye drops are monitored during the study.

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

Diabetic patients participating in this study will be randomed to get 1 drop or 3 drops of dilating drug. And one eye of each patient will be randomed to get 1 drop of anesthetics, while the other eye does not. So there are 4 groups of eyes in the study. Group 1 receive 1 drop of dilating drug. Group 2 receive 1 drop of anesthetics + 1 drop of dilating drug. Group 3 receive 3 drops of dilating drug. And group 4 receive 1 drop of anesthetics + 3 drops of dilating drug. Pupil size will be measured before and after the drops.

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.
84

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

  • Thailand
      • Chon Buri, Thailand, 20131
        • Burapha University

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:

  • Diabetic patients who were scheduled for diabetic retinopathy screening at OPD eye
  • Age 18 years or older

Exclusion Criteria:

  • Conditions potentially affecting pupillary reaction (e.g., history of uveitis, previous intraocular surgery, posterior synechiae)
  • Known allergies to the study medications
  • Systolic blood pressure > 160 mmHg
  • Diastolic blood pressure > 100 mmHg
  • Pulse rate > 100 beats/min

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: Diagnostic
  • 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: 1 drop
1 drop of a 0.8% tropicamide - 5% phenylephrine combination
Drug: 1 drop of a 0.8% tropicamide + 5% phenylephrine combination
1 drop of a 0.8% tropicamide (muscarinic antagonist) + 5% phenylephrine (α1-adrenergic agonist) combination
Experimental: 2 drops
1 drop of tetracaine and 1 drop of a 0.8% tropicamide - 5% phenylephrine combination
Drug: 1 drop of 0.5% tetracaine and 1 drop of a 0.8% tropicamide + 5% phenylephrine combination
1 drop of 0.5% tetracaine (anesthetics) and 1 drop of a 0.8% tropicamide (muscarinic antagonist) + 5% phenylephrine (α1-adrenergic agonist) combination
Experimental: 3 drops
3 drops of a 0.8% tropicamide - 5% phenylephrine combination
Drug: 3 drops of a 0.8% tropicamide + 5% phenylephrine combination
3 drops of a 0.8% tropicamide (muscarinic antagonist) + 5% phenylephrine (α1-adrenergic agonist) combination
Experimental: 4 drops
1 drop of tetracaine and 3 drops of a 0.8% tropicamide - 5% phenylephrine combination
Drug: 1 drop of 0.5% tetracaine and 3 drops of a 0.8% tropicamide + 5% phenylephrine combination
1 drop of 0.5% tetracaine (anesthetics) and 3 drops of a 0.8% tropicamide (muscarinic antagonist) + 5% phenylephrine (α1-adrenergic agonist) combination

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
Pupillary size
Time Frame: 30 minutes
Measurement of pupillary size in millimeters (at baseline, then every 10 minutes)
30 minutes

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
Systolic blood pressure
Time Frame: 30 minutes
Measurement of systolic blood pressure (at baseline, then every 10 minutes)
30 minutes
Diastolic blood pressure
Time Frame: 30 minutes
Measurement of diastolic blood pressure (at baseline, then every 10 minutes)
30 minutes
Pulse rate
Time Frame: 30 minutes
Measurement of pulse rate (at baseline, then every 10 minutes)
30 minutes
Ocular discomfort
Time Frame: When all measurements concluded (at minute 30)
Patients report of ocular discomfort during topical administration and the measurement of pupillary size in pain score (0-10)
When all measurements concluded (at minute 30)

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.
Burapha University

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: Nattawat Asawaworarit, M.D., Burapha University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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.
November 4, 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.
January 31, 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.
January 31, 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).
March 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.
March 24, 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.
March 27, 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.
March 27, 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.
March 24, 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.
March 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.
  • IRB1-052/2567

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

IPD used in the results publication

IPD Sharing Time Frame

IPD and supporting information will be available one year after publicaiton and for two years period.

IPD Sharing Access Criteria

Direct contact to the corresponding author

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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