Smoking ( Cigarette)NCT07580040
Acute Ocular Effects of Cigarette Smoking
An observational study of Smoking ( Cigarette) and Cornea, run by Istanbul University at 1 site in Turkey (Türkiye).
Trial summary
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… Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Smoking ( Cigarette), Cornea, Anterior Eye Segment Measurements
- What is being tested?
- Cigarette Smoking Exposure and No Smoking Exposure
- How many people
- 92 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 15 Feb 2026to 1 Jun 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Healthy adult smokers and non-smokers aged 18 to 60 years are planned to be included in this single-center study.
Who may be able to join
- 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
Who cannot join
- 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
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- Former smoking history in the control group
- Use of electronic cigarettes or other tobacco products
- Inability to cooperate adequately for accurate measurement
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Istanbul University, Istanbul Faculty of Medicine
Istanbul, 34093
About this study
Official title: 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.
Read the 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.
- Being tested
- Cigarette Smoking Exposure, No Smoking Exposure
- Keywords
- Cigarette Smoking, Corneal Tomography, Biometry, Pentacam, Anterior Segment, Corneal Densitometry
- Medical subject headings
- Cigarette Smoking, Corneal Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cigarette Smoking ExposureOther
Participants in the smoking group smoked cigarettes during a standardized 10-minute outdoor period between baseline and post-exposure assessments.
No Smoking ExposureOther
Participants in the control group remained in the same outdoor environment for 10 minutes without smoking between baseline and post-exposure assessments.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: Other: Cigarette Smoking Exposure | |
| 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. Receives: Other: No Smoking Exposure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Pentacam-measured corneal pachymetry at the pupil center after acute cigarette smoking exposure
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.
Measured: Baseline and immediately after a standardized 10-minute outdoor exposure period
Secondary outcomes (1)
Change in Pentacam-measured corneal densitometry in the anterior 0-2 mm zone after acute cigarette smoking exposure
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.
Measured: Baseline and immediately after a standardized 10-minute outdoor exposure period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 May 2026
- Study start15 Feb 2026
- Primary completion1 May 2026
- Study completion1 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Smoking ( Cigarette)Studies of the same condition, open and under way.
- More trials run by Istanbul UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 92 participants (actual)
Sponsor and investigators
- Lead sponsor
- Istanbul University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Semih Çakmak, Istanbul University
- Investigators
- Semih Çakmak, Principal investigator, Istanbul University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07580040
- Sponsor's protocol ID
- IstanbulU-2026-3901546
- Status last verified
- Nov 2026
- First submitted
- 17 Apr 2026
- Last updated
- 4 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: 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.
Study at a glance
From the registry record, last updated by the sponsor on 4 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Acute Effects of Cigarette Smoking on Corneal Tomographic and Biometric Parameters: A Prospective Controlled Study
- ClinicalTrials.gov ID
- NCT07580040
- Acronym / sponsor ID
- IstanbulU-2026-3901546
- Keywords
- Cigarette Smoking, Corneal Tomography, Biometry, Pentacam, Anterior Segment, Corneal Densitometry
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 92 participants (actual)
- Lead sponsor
- Istanbul UniversityUniversity, hospital or other
- Study start
- 15 Feb 2026 (actual)
- Primary completion
- 1 May 2026 (actual)
- Study completion
- 1 Jun 2026 (actual)
- First posted
- 12 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Smokers | – | Other: Cigarette Smoking ExposureHealthy 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. |
| Non-smokers | – | Other: No Smoking ExposureHealthy 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. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Healthy adult smokers and non-smokers aged 18 to 60 years are planned to be included in this single-center study.
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (9 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cigarette Smoking ExposureParticipants in the smoking group smoked cigarettes during a standardized 10-minute outdoor period between baseline and post-exposure assessments. | Other | Smokers |
| No Smoking ExposureParticipants in the control group remained in the same outdoor environment for 10 minutes without smoking between baseline and post-exposure assessments. | Other | Non-smokers |
Primary outcome
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.
1 secondary outcome
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
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Nov 2026.
- Individual participant dataSharing planned: No. 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Semih Çakmak principal investigator
Istanbul University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Smoking ( Cigarette) and Cornea, run by Istanbul University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Nov 2026.