To evaluate corneal topographic pattern & its correlation with refractive status of the eye .

This study will be established in The Future Center for refractive surgery, Sohag, Egypt.

This study will include 100 eyes of patients aged over 15 years. All patients were subjected to topography imaging.

Using Oculus Pentacam® which is s a rotating Scheimpflug camera. The rotational measuring procedure generates Scheimpflug images in three dimensions.

The scheimpflug principle describes the optical imaging condition when the plane of an object is not parallel to the film of the camera and has to cut each other in one line or one point of intersection with the advantage to achieve wide depth of focus.

Scheimpflug imaging attains a wide and high depth-of-focus , providing sharp images that include information from an anterior corneal surface through to the posterior crystalline capsule; this depends mainly on media transparency and pupil size .

Inclusion Criteria:

• Patients aging more than 15 years old
• All patients are with visual acuity (uncorrected, with habitual correction, and best spectacle correction).
• There is no restrictions on the range and regularity of keratometry.

Exclusion Criteria:

• Patients with a history of any trauma to the eye.

• Patients with recent contact lens wear.

• history of ocular surgery .

• Patients with distance corrected visual acuity or abnormal retinoscopy examination (e.g., scissoring reflex).

  5. If there was any error in reading the topographic map. 6. Patients with anemotropic refraction.