Femtosecond Laser Versus Microkeratome in Creating Corneal Flaps in LASIK

Study Overview
=================
Brief Summary
-----------------
Since the cornea is the main responsible for the refraction of the eye, as its refractive power is greater than 70% of the total refraction of the eye, so modification of its refractive properties are used to change the optical system of the eye. Hence, laser-assisted in situ keratomileusis has become the most commonly procedure used to correct the refractive errors of the eye. The most important step in laser-assisted in situ keratomileusis is the creation of the corneal flap, which its thickness may judge the whole outcome of the surgery . So trying to minimize the variation in the thickness of the resultant flap in comparison to what planned flap thickness preoperatively become our target.

Detailed Description
-----------------
As laser-assisted in situ keratomileusis procedure started to use automated microkeratomes in creating corneal flaps since 1989, and science go on until United states Food and Drug Administration approved the IntraLase laser for flap creation in January 2000 femtosecond lasers work by emitting light pulses of short duration (10-15 s) at 1053 nm wavelength that cause photodisruption of the tissue with minimum collateral damage . This enables no blade incisions to be performed within the tissue at various patterns and depth with high precision. Aim of the work To evaluate and compare the variation in corneal flap thickness created from use of a femtosecond laser and a MORIA microkeratome when making a 110-µm- and 90- µm thick corneal flap and to identify the potential factors that affect corneal flap thickness.

Official Title
-----------------
Predictability of Corneal Flap Thickness in Lasik Using Femtosecod Laser in Comparison to Moria Microkeratome

Conditions
-----------------
Femtosecond Laser in Comparison to Moria Microkeratome in Creating Corneal Flaps

Intervention / Treatment
-----------------
* Device: anterior segment Ocular Coherence Tomography


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age 18-40 year Preoperative spherical refraction of -2.00 to -10.00D. Refractive cylinder of less than -3.00D. A stable refractive state for 2 years. An intraocular pressure (IOP) of <22 mm Hg. Exclusion Criteria: A history of any systemic autoimmune disease. A history of diabetes. Other ophthalmic disorders. A history of ocular trauma and surgical history.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| femtosecond_laser<br>participants had there lasik corneal flap creation using femtosecond laser | Device: anterior segment Ocular Coherence Tomography<br>* anterior segment OCT (Ocular Coherence Tomography) a device shows imaging of anterior segment of the eye and able to show corneal layers and measures its thickness.<br>|
| moria_microkeratome<br>participants had there lasik corneal flap creation using moria microkeratome | Device: anterior segment Ocular Coherence Tomography<br>* anterior segment OCT (Ocular Coherence Tomography) a device shows imaging of anterior segment of the eye and able to show corneal layers and measures its thickness.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| corneal flap thickness | measuring the corneal flap thickness in nanometers postoperatively by anterior segment OCT | 7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| uncorrected visual acuity | identifying uncorrected visual acuity postoperatively | 7 days | 
| best corrected visual acuity | identifying best corrected visual acuity postoperatively | 7 days | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
lasik, flap_thickness, femtosecond, laser, moria, microkeratome