Skip to main content
OpenTrials
Not Yet Recruiting

NCT Number: NCT07518316

Factors Influencing Subjective Visual Quality in Human Eyes

To assess subjective visual symptoms using the QoV questionnaire, measure pupil size using the Atongmu Pupillometer, measure wavefront aberrations using the OPD-Scan III Aberrometer, and measure/calculate the effective optical zone using the Pentacam system. The relationships between pupil size, higher-order aberrations (HOAs), effective optical zone after refractive surgery, and subjective visual symptoms will be explored.

Not Yet Recruiting

Trial opening soon.

Get Notified

Key information

Age range

18 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

About this study

The sample size will be calculated using an appropriate sample size calculation formula. Using a random number table method, 1200 subjects scheduled for preoperative examination at the Refractive Surgery Center of Tianjin Eye Hospital between December 1, 2025, and May 1, 2026, will be randomly selected. Data including age, gender, spectacle wear status, uncorrected visual acuity (UCVA), spherical power, cylindrical power, intraocular pressure (IOP), mean keratometry (Km), corneal thickness, axial length, and degree of lens and vitreous opacities will be recorded. Pupil size under photopic, mesopic, and scotopic conditions will be measured using the Atongmu Pupillometer. Wavefront aberrations will be measured using the OPD-Scan III Aberrometer (OPD: Optical Path Difference). Subjects will complete the Quality of Vision (QoV) questionnaire.

Additionally, based on sample size calculation, using a random number table method, 300 subjects undergoing refractive surgery at the Refractive Surgery Center of Tianjin Eye Hospital between December 1, 2025, and May 1, 2026, will be randomly selected and prospectively followed up until 3 months postoperatively. Pupil size under photopic, mesopic, and scotopic conditions will be measured using the Atongmu Pupillometer. Wavefront aberrations will be measured using the OPD-Scan III Aberrometer before and after surgery. The effective optical zone (EOZ) will be measured and calculated using the Pentacam three-dimensional anterior segment analysis system. The QoV questionnaire will be administered postoperatively. Data will be collated and analyzed using statistical methods.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Myopic or myopic astigmatism patients aged 18 to 45 years.
  • Transparent ocular media, absence of ocular diseases such as corneal leucoma, cataract, etc.
  • Round pupils with normal light reflex, absence of dyscoria, corectopia, significant persistent pupillary membrane, or absence of the pupil.
  • Absence of severe psychological or psychiatric disorders, ability to cooperate with examinations and questionnaire completion.
  • Subject agrees to participate in this clinical study and cooperate with examinations and related procedures.

Exclusion criteria

  • Opacities of the ocular media, such as corneal leucoma, cataract, etc.
  • Pupil deformation, displacement, significant persistent pupillary membrane, or absence of the pupil.
  • Severe psychological or psychiatric disorders.
  • Concurrent diagnosis of other ocular diseases (e.g., glaucoma, corneal opacity, uveitis, etc.).
  • History of ocular surgery or trauma.
  • Nystagmus or inability to cooperate.

Treatment and study plan

Corneal refractive surgery

Procedure

Corneal refractive surgery aims to correct refractive errors by altering the shape of the anterior surface of the cornea or by changing its refractive properties.

Primary outcomes

  1. Total Higher-Order Aberrations (HOAs)

    Time frame: 3 months

    Root mean square (RMS) of total higher-order aberrations measured using the OPD-Scan III.

    Units: micrometres (µm)

  2. Effective Optical Zone Diameter

    Time frame: 3 months

    Effective optical zone diameter measured using the Pentacam system. Units: millimetres (mm)

  3. Central Corneal Thickness

    Time frame: 3 months

    Central corneal thickness measured using the Pentacam system. Units: micrometres (µm)

  4. Coma Aberration (RMS)

    Time frame: 3 months

    Coma aberration (root mean square) measured using the OPD-Scan III. Units: micrometres (µm)

  5. Trefoil Aberration (RMS)

    Time frame: 3 months

    Trefoil aberration (root mean square) measured using the OPD-Scan III. Units: micrometres (µm)

  6. Spherical Aberration (Zernike Z₄⁰, RMS)

    Time frame: 3 months

    Spherical aberration expressed as Zernike coefficient Z₄⁰ (RMS), measured using the OPD-Scan III.

    Units: micrometres (µm)

Study contacts

Contact information is provided by the study sponsor or research team.

Sponsors and collaborators

Lead sponsor

Tianjin Eye Hospital

Other

Registry information

Official study title

Factors Influencing Subjective Visual Quality in Normal Human Eyes and Before and After Refractive Surgery

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Apr 8, 2026
Registry last updated
Apr 8, 2026

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.

Published trials that share one or more normalized conditions with this study.