Corneal Topography Asymmetry Indices Changes After Corneal Refractive Surgery
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Myopia
- Sponsor
- Tanta University
- Enrollment
- 30
- Locations
- 1
- Primary Endpoint
- To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK.
- Status
- Completed
- Last Updated
- 4 years ago
Overview
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.
Investigators
Dina Tadros
Lecturer of ophthalmology , Tanta University Hospital
Tanta University
Eligibility Criteria
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
Outcomes
Primary Outcomes
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 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