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

Completed

Conditions

Intervention / Treatment

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

Interventional

Enrollment (Actual)

84

Phase

  • 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

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
Intervention / Treatment
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

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

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

Burapha University

Investigators

  • 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)

November 4, 2024

Primary Completion (Actual)

January 31, 2025

Study Completion (Actual)

January 31, 2025

Study Registration Dates

First Submitted

March 19, 2026

First Submitted That Met QC Criteria

March 24, 2026

First Posted (Actual)

March 27, 2026

Study Record Updates

Last Update Posted (Actual)

March 27, 2026

Last Update Submitted That Met QC Criteria

March 24, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID 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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