Measuring the Changes of the Intraocular Pressure After Corneal Laser Refractive Surgery Using Different Techniques

To evaluate the changes that occur in the intraocular pressure after corneal refractive surgery either PRK , LASIK and femtosecond laser by using Corvis CT results and applanation tonometer

Study Overview

• Status: Not yet recruiting
• Conditions: Intraocular Pressure; Refractive Surgery
• Intervention / Treatment: Other: Corvis machine

Detailed Description

This study will be prospective study. 50 Patients who will undergo refractive surgery referred from the out-patient clinic of Tanta University hospital between December 2025 and December 2026 will be included in the study . The patient will be randomly selected to do either LASIK, PRK or femtosecond laser LASIK

Patients who will undergo refractive surgery either PRK, LASIK or femtosecond laser with age between 19 and 35 years old , Myopia range from (-2.00 to -6.00 Diopter) and to maintain stability of the data we will use only the right eye of each patient will be included on the study

Kertoconus, Corneal scarring, Previous corneal infections, Minimum corneal thickness at the thinnest location less than 400 µm, History of uveitis or ocular allergy and Pre-existing glaucoma will be excluded from the study.

Age, sex, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest and cycloplegic refraction, Slit lamp biomicroscopy, fundus examination , Central corneal thickness (CCT) and average Keratometer (K) data will be collected

Intraocular pressure will be measured by by two methods : Corvis CT and applanation tonometer for each patient and will be recorded, all the data will be collected before the refractive surgery and one month after refractive surgery

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Dina Tadros, Ass Professor of Ophthalmology; Phone Number: +201224093354; Email: dina.tadros@med.tanta.edu.eg

Study Locations

• Egypt
  • Tanta, Egypt, 31515
    • Tanta Univeristy Hospital
    • Contact: Tamer Ibrahim, Ass professor; Phone Number: +201001243049; Email: dinasabry71@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age between 19 and 35 years old
• Myopia range from (-2.00 to -6.00 Diopter) .

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Measuring intraocular pressure by using different techniques	Other: Corvis machine; Measuring intraocular pressure by different methods and compare the results

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measuring intraocular pressure	Intraocular pressure will be measured by in mmHg and by two methods : Corvis CT and applanation tonometer for each patient and will be recorded	-The data collected will be before that laser surgery and one month after surgery

Collaborators and Investigators

• Sponsor: Tanta University

Publications and helpful links

General Publications

• 1. Bailey MD, Zadnik K (2007) Outcomes of LASIK for myopia with FDA-approved lasers. Cornea 26(3):246-254 2. Sridhar MS, Rao SK, Vajpayee RB, Aasuri MK, Hannush S, Sinha R (2002) Complications of laser-in situ-ker- atomileusis. Indian J Ophthalmol 50(4):265-282 3. Mohammadi SF, Nabovati P, Mirzajani A, Ashrafi E, Vakilian B (2015) Risk factors of regression and under- correction in photorefractive keratectomy: a case-control study. Int J Ophthalmol 18;8(5): 933-937 4. Diakonis VF, Kankariya VP, Kymionis GD, Kounis G, Kontadakis G, Gkenos E, Grentzelos MA, Hajithanasis G, Yoo SH, Pallikaris IG (2014) Long term followup of pho- torefractive keratectomy with adjuvant use of mitomycin C. J Ophthalmol 2014:821920 5- dos Santos AM, Torricelli AA, Marino GK, Garcia R, Netto MV, Bechara SJ, Wilson SE. Femtosecond Laser-Assisted LASIK Flap Complications. J Refract Surg. 2016 Jan;32(1):52-9 6- Wang LK, Tian L and Zheng YP. Determining in vivo elasticity and viscosity with dynamic Scheimpflug imaging analysis in keratoconic and healthy eyes. J Biophotonics, 2016; 9: 454-463. 7.ConsejoA,MelcerT,RozemaJJ.Introductiontomachinelearningforophthalmologists.SeminOphthalmol.2019;34(1):19 _41.

Study record dates

Study Major Dates

• Study Start (Estimated): April 20, 2026
• Primary Completion (Estimated): October 20, 2026
• Study Completion (Estimated): January 16, 2027

Study Registration Dates

• First Submitted: January 17, 2026
• First Submitted That Met QC Criteria: April 17, 2026
• First Posted (Actual): April 24, 2026

Study Record Updates

• Last Update Posted (Actual): April 24, 2026
• Last Update Submitted That Met QC Criteria: April 17, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 36264PR1310100/12/25

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Results after statistical analysis will be shared in the manuscript

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No