Corneal Topography Asymmetry Indices Changes After Corneal Refractive Surgery

Completed

• Conditions: Myopia
• Interventions: Other: Refractive surgery

• Registration Number: NCT04589091
• Lead Sponsor: Tanta University

Brief Summary

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

Detailed Description

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

1. Average keratometric value (K mean) in diopters

2. Maximum simulated keratometry (Kmax) in diopters

3. Index of Surface Variance (ISV) in microns

4. Index of Vertical Asymmetey (IVA) in microns

5. Radii Minimum (R min) in microns

6. Index of height asymmetry (IHA) in microns

7. Index of height decantation (IHD) in microns

8. 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.

Study Timeline

• Study First Submitted: 2020-10-13
• Study First Submitted QC: 2020-10-13
• Study First Posted: 2020-10-19
• Study Start: 2021-04-13
• Primary Completion: 2021-10-30
• Study Completion: 2022-01-30
• Status Verified: 2022-02
• Last Update Submitted: 2022-02-07
• Last Update Posted: 2022-02-08

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 30

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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Group(2): Patient underwent LASIK	Refractive surgery	-
Group(1): Patient who underwent PRK	Refractive surgery	-

Primary Outcome Measures

Name	Time	Method
To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK.	6 months	Using the results of measurements of Scheimpflug camera (Pentacam Oculus- Germany) :that includes the following indices; 1. Average keratometric value (K mean) in diopters; 2. Maximum simulated keratometry (Kmax) in diopters; 3. Index of Surface Variance (ISV) in microns; 4. Index of Vertical Asymmetey (IVA) in microns; 5. Radii Minimum (R min) in microns; 6. Index of height asymmetry (IHA) in microns; 7. Index of height decantation (IHD) in microns; 8. 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

Trial Locations

Locations (1)

Tanta University Hospital; 🇪🇬 Tanta, El-Garbeia, Egypt