Acute Ocular Effects of Cigarette Smoking

May 5, 2026 updated by: Semih Çakmak, Istanbul University

Acute Effects of Cigarette Smoking on Corneal Tomographic and Biometric Parameters: A Prospective Controlled Study

This prospective study aims to evaluate the short-term effects of smoking on corneal tomographic and biometric measurements in healthy adults. After baseline examinations and measurements are taken in both smoking and non-smoking participants, the same measurements will be repeated after 10 minutes of external exposure, and within-group and between-group changes will be compared. The aim of the study is to determine whether acute smoking exposure leads to measurable immediate changes in corneal tomographic and biometric parameters.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study is a single-center, prospective, and controlled study designed to evaluate the short-term effects of smoking on corneal tomographic and biometric measurements in healthy adults. The study aimed to include 46 smokers and 46 non-smokers. To avoid inter-eye correlation, only the right eye of each participant was evaluated. All participants initially underwent a full ophthalmological examination and measurements were taken using a Pentacam device. Afterward, all participants waited in standard outdoor conditions for 10 minutes. During this time, participants in the smoking group smoked, while participants in the control group did not smoke. The same measurements were repeated at the end of the period. The study aimed to compare within-group and between-group differences in changes.

Study Type

Observational

Enrollment (Estimated)

90

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

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

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Healthy adult smokers and non-smokers aged 18 to 60 years are planned to be included in this single-center study.

Description

Inclusion Criteria:

  • Healthy adults aged 18 to 60 years
  • Current smokers in the smoking group
  • Never-smokers in the control group
  • Willing and able to undergo ophthalmic examination and Pentacam AXL measurements

Exclusion Criteria:

  • History of ocular surgery or ocular trauma
  • Presence of corneal disease, retinal disease, or ocular surface disorder
  • Clinically significant dry eye disease
  • Contact lens use within the last 2 weeks
  • Use of medications that may affect the ocular surface or pupillary dynamics, including anticholinergics or sympathomimetics
  • Systemic diseases such as diabetes mellitus or hypertension
  • Former smoking history in the control group
  • Use of electronic cigarettes or other tobacco products
  • Inability to cooperate adequately for accurate measurement

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Smokers
Healthy adult participants with active cigarette smoking exposure who underwent baseline ophthalmic examination and Pentacam measurements, followed by repeat measurements after a standardized 10-minute outdoor period during which they smoked.
Other: Cigarette Smoking Exposure
Participants in the smoking group smoked cigarettes during a standardized 10-minute outdoor period between baseline and post-exposure assessments.
Non-smokers
Healthy adult participants without cigarette smoking exposure who underwent baseline ophthalmic examination and Pentacam measurements, followed by repeat measurements after a standardized 10-minute outdoor period under the same environmental conditions without smoking.
Other: No Smoking Exposure
Participants in the control group remained in the same outdoor environment for 10 minutes without smoking between baseline and post-exposure assessments.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Pentacam-measured corneal pachymetry at the pupil center after acute cigarette smoking exposure
Time Frame: Baseline and immediately after a standardized 10-minute outdoor exposure period
Change (post-exposure minus baseline) in corneal pachymetry at the pupil center, measured in micrometers (µm) using Pentacam. The magnitude of change will be compared between smokers and non-smokers.
Baseline and immediately after a standardized 10-minute outdoor exposure period

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Pentacam-measured corneal densitometry in the anterior 0-2 mm zone after acute cigarette smoking exposure
Time Frame: Baseline and immediately after a standardized 10-minute outdoor exposure period
Change (post-exposure minus baseline) in corneal densitometry in the anterior 0-2 mm zone, measured in grayscale units (GSU) using Pentacam. The magnitude of change will be compared between smokers and non-smokers.
Baseline and immediately after a standardized 10-minute outdoor exposure period

Collaborators and Investigators

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

Sponsor

Istanbul University

Investigators

  • Principal Investigator: Semih Çakmak, Istanbul 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)

February 15, 2026

Primary Completion (Estimated)

May 1, 2026

Study Completion (Estimated)

May 1, 2026

Study Registration Dates

First Submitted

April 17, 2026

First Submitted That Met QC Criteria

May 5, 2026

First Posted (Actual)

May 12, 2026

Study Record Updates

Last Update Posted (Actual)

May 12, 2026

Last Update Submitted That Met QC Criteria

May 5, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IstanbulU-2026-3901546

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared because the study was not designed with a data-sharing plan and the dataset contains participant-level information.

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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