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Completed

NCT Number: NCT07028736

Dry Eye Disease and Retinal Nerve Fiber Layer Thickness in Chronic Smokers

This study aimed to examine the impact of long-term smoking on dry eye parameters and retinal nerve fiber layer thickness in individuals who are chronic smokers.

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Key information

Conditions

Dry Eye Disease Chronic Smoking Dry Eye Syndromes Eye Diseases Lacrimal Apparatus Diseases Retinal Nerve Fiber Layer

Age range

30 year–60 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Cairo University

Cairo, 12613, Egypt

About this study

Dry eye disease (DED) is a multifaceted disorder of the ocular surface characterized by instability of the tear film, which subsequently leads to symptoms such as ocular discomfort, visual disturbances, and potential damage to the surface of the eye.

Cigarette smoking has been recognized as a possible contributing factor to the development of DED, with various reports suggesting that it may alter tear film composition and stability, leading to ocular surface damage.

Chronic smoking can lead to oxidative stress, vascular dysfunction, and inflammation, which may contribute to retinal nerve fiber layer (RNFL) thinning and optic nerve damage.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age from 30 to 60 years.
  • Both sexes.
  • Chronic smokers.

Exclusion criteria

  • History of ocular surface diseases affecting tear production or secretion (such as Sjogren's syndrome or Stevens-Johnson disease).
  • Conjunctivitis.
  • Blepharitis.
  • Chronic contact lens use or gross lid abnormalities.
  • Preexisting glaucoma.
  • Retinal diseases.
  • Optic nerve pathology.
  • Ocular trauma.
  • Chemical burns.
  • Recent eye surgery (within three months).
  • Trachoma-related complications

Treatment and study plan

Dry eye assessment

Other

Dry eye assessment was performed using the Mediworks Dry Eye Diagnostic System.

Primary outcomes

  1. Non-invasive tear film breakup time

    Time frame: During examination (Baseline)

    Non-invasive tear film breakup time (NIBUT) was automatically analyzed using artificial intelligence, with results classified as Grade 0 (normal, first rupture time >10s), Grade 1 (warning, 6- 9s), or Grade 2 (dry eye, ≤5s)

Secondary outcomes

  1. Tear meniscus height

    Time frame: During examination (Baseline)

    Tear meniscus height (TMH) values above 0.2mm were considered healthy, while lipid layer thickness was graded from 1 (<30nm) to 4 (>80nm).

  2. Lipid layer thickness

    Time frame: During examination (Baseline)

    Lipid layer thickness was graded from 1 (<30nm) to 4 (>80nm).

  3. Ocular Surface Disease Index (OSDI) score

    Time frame: During examination (Baseline)

    The ocular surface disease index (OSDI) score was categorized as normal (≤12), mild (13-22), moderate (23-32), or severe (≥33).

  4. Retinal nerve fiber layer thickness

    Time frame: During examination (Baseline)

    Retinal nerve fiber layer (RNFL) thickness was measured using Fourier-domain OCT Optovue RTVue (Optovue Inc., Fremont, CA, USA).

  5. Correlations between dry eye parameters and Ocular Surface Disease Index (OSDI) score

    Time frame: During examination (Baseline)

    Correlations between dry eye parameters and Ocular Surface Disease Index (OSDI) score was assessed.

  6. Correlations between dry eye parameters and retinal nerve fiber layer (RNFL) thickness in both groups

    Time frame: During examination (Baseline)

    Correlations between dry eye parameters and retinal nerve fiber layer (RNFL) thickness in both groups was assessed.

Sponsors and collaborators

Lead sponsor

Cairo University

Other

Registry information

Official study title

Assessment of Dry Eye Disease and Retinal Nerve Fiber Layer Thickness in Chronic Smokers

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Jun 19, 2025
Registry last updated
Jun 19, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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