Astigmatism in Keratoconus Patients

Study Overview
=================
Brief Summary
-----------------
Keratoconus is a bilateral (but usually asymmetrical) non-inflammatory progressive thinning process of the cornea. It manifests as characteristic cone-like ectasia of the cornea associated with irregular stromal thinning, resulting in a cone-like bulge , which causing irregular astigmatism and vision impairment.

Detailed Description
-----------------
Keratoconus is the most common form of corneal ectasia, with an incidence of 50-230 per 100,000 persons.Pentacam used diagnose & detect the progression in patients with keratoconus and also provide a detailed information about corneal tomography and topography. In the last few years, it has been shown that in healthy individuals the posterior corneal surface has not only a different amount of astigmatism but also a different alignment of the steep meridian. The aim of this research is to compare the amount and axis alignment of anterior and posterior corneal astigmatism in keratoconus with a healthy controlled group .

Official Title
-----------------
Comparison of Anterior and Posterior Corneal Astigmatism in Patients With Keratoconus and Controls

Conditions
-----------------
Keratoconus

Intervention / Treatment
-----------------
* Device: Pentacam


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients diagnosed with keratoconus using the following criteria: Specific diagnostic signs is asymmetric refractive errors with high progressive or irregular astigmatism, and elevated keratometry values, scissoring of the red reflex, Vogt striae, Fleischer rings, inferior or central steepening on topography with abnormal localized steepening . Exclusion Criteria: Unwillingness to participate in the study . Corneal scarring. Any ectatic conditions that were not explicitly keratoconus such as keratoglobus and pellucid marginal degeneration . Previous ocular surgery.
Sexes Eligible for Study
-----------------
All

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

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

Design Details

Primary Purpose: Screening
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Patients with keratoconus<br>Pentacam will be used for comparison between astigmatism in patients with keratoconus and normal people at the same age and sex. | Device: Pentacam<br>* Pentacam will be used to measure the magnitude and axis orientation of anterior and posterior corneal astigmatism.<br>|
| Placebo Comparator: Normal people at the same age and sex<br>Pentacam will be used for comparison between astigmatism in patients with keratoconus and normal people at the same age and sex. | Device: Pentacam<br>* Pentacam will be used to measure the magnitude and axis orientation of anterior and posterior corneal astigmatism.<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison between astigmatism in patients with keratoconus and normal people. | Pentacam will be used for comparison between astigmatism in patients with keratoconus and normal people at the same age and sex | Two years |