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Completed

NCT Number: NCT04589091

Corneal Topography Asymmetry Indices Changes After Corneal Refractive Surgery

To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK.

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Key information

Conditions

Myopia Eye Diseases Refractive Errors

Age range

19 year–35 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Tanta University Hospital

Tanta, El-Garbeia, 31515, Egypt

About this study

Retrospectively review the medical records of all patients who underwent refractive surgery referred from the out-patient clinic of Tanta University hospital between September 2015 and September 2020 .

Data collection will include:

Preoperative and postoperative Evaluation: Age, sex, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest and cycloplegic refraction, Slit lamp biomicroscopy, fundus examination.

Data of Corneal Tomography keratometric using Scheimpflug camera (Pentacam Oculus- Germany) :that includes the following indices

  • Average keratometric value (K mean) in diopters
  • Maximum simulated keratometry (Kmax) in diopters
  • Index of Surface Variance (ISV) in microns
  • Index of Vertical Asymmetey (IVA) in microns
  • Radii Minimum (R min) in microns
  • Index of height asymmetry (IHA) in microns
  • Index of height decantation (IHD) in microns
  • Aberration coefficient (ABR)

The data of the pentacam will be collected pre-operative and analyzed at 1 month, 3 months and 6 months with recording of the complications.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Patients who underwent refractive surgery either PRK, LASIK with age between 19 and 35 years old

Exclusion criteria

  • Kertoconus.
  • Corneal scarring.
  • Previous corneal infections.
  • Minimum corneal thickness at the thinnest location less than 400 µm.
  • History of uveitis or ocular allergy.
  • Pre-existing glaucoma.
  • Data not available

Treatment and study plan

Refractive surgery

Other

Refractive surgery for correction of error of refraction

Primary outcomes

  1. To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK.

    Time frame: 6 months

    Using the results of measurements of Scheimpflug camera (Pentacam Oculus- Germany) :that includes the following indices

    • Average keratometric value (K mean) in diopters
    • Maximum simulated keratometry (Kmax) in diopters
    • Index of Surface Variance (ISV) in microns
    • Index of Vertical Asymmetey (IVA) in microns
    • Radii Minimum (R min) in microns
    • Index of height asymmetry (IHA) in microns
    • Index of height decantation (IHD) in microns
    • Aberration coefficient (ABR)

    The numbers from preoperative records will be compared with postoperative records after the refractive surgery is done . All the values will be expressed as mean ± standard deviation and the data will be analyzed as 1 months, 3 months and 6 months after surgery

Sponsors and collaborators

Lead sponsor

Tanta University

Other

Registry information

Important dates

Study start
2021
Primary completion
2021
Study completion
2022
First posted
Oct 19, 2020
Registry last updated
Feb 8, 2022

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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