Correlation Between Corneal Topographic Patterns and Refractive Status Of The Eye in Sohag City,Egypt
Phase: NA
Conditions: Eye Change
Sponsor: Sohag University

Sohag University 
Faculty of Medicine 
Department of Ophthalmology 
 
 
Official Title: 
Correlation between Corneal Topographic Patterns and 
Refractive Status of the Eye in Sohag City, Egypt 
 
NCT number: N/A 
 
Document Date:  
22 September 2022 
 
 
 
 
 
 
 
 
 
 

Sohag University 
Faculty of Medicine 
Department of Ophthalmology 
 
Correlation between Corneal Topographic 
Patterns and 
Refractive Status of the Eye in Sohag City, 
Egypt
 
Protocol for thesis Submitted for Partial Fulfillment of the Master 
Degree in Ophthalmology 
 
by
 
Presented
 
Ahmed Abdallah Abd-Elal 
 
Resident in ophthalmology Department 
Akhemim Cental Hospital 
 
Supervised by
 
       
 
Mohammed Iqbal Hafez 
Professor of ophthalmology, Faculty of Medicine, Sohag University 
Amr Mounir 
Assistant Professor of ophthalmology, Faculty of Medicine, Sohag 
University 
Mohamed Ezz Eldawla 
Lecturer of Ophthalmology, Faculty of Medicine, Sohag University 
Sohag University 2022 

INTRODUCTION 
 
The cornea is the most important refractive surface of the eye, and its shape directly 
affects the quality of vision and degree of refractive error. Knowledge of normal shape 
of the human cornea, and the possibilities  of inter-individual variations in corneal 
topography in populations helps in many diagnostic and therapeutic cases such as 
contact lens fitting, management of ectatic disorders, and evaluation of patients for 
refractive surgery.(1,2,3) In order to determine the early changes in the anterior level of 
the cornea that occur in the early stages of the disease, we first need to analyze the 
spectrum of normal topography that exists in populations. Since the prevalence of 
keratoconus in the Middle East including Egypt has been proven to be higher, So, It’s 
important to release studies about this material.(4,5,6,7,8)
 
 
Corneal topography is a well-known method for evaluating corneal shape. The common 
topographic corneal patterns have been discussed widely, and different patterns have 
been proposed as normal topographic patterns. This classification becomes especially 
important in differentiating diseases that affect the cornea, such as mild keratoconus, 
from normal when planning to have a corneal-based surgery. Knowing the frequency of 
each normal pattern in specific populations, such populations with different refractive 
status, is necessary for estimating the probability of being abnormal in each individual 
patient.
 
 
Aim of the work 
To evaluate corneal topographic pattern & its correlation with refractive status of the 
eye . 
 

Patient And Methods 
Type of the study : 
 Prospective observational cross-sectional study. 
This study will be established in The Future Center for refractive surgery, 
Sohag, Egypt. 
This study will include 100 eyes of 100 patients aged over 15 years. All patients were 
subjected to topography imaging and subjective, manifest and cycloplegic refractions.  
Inclusion Criteria: 
1. Patients aging more than 15 years old 
2. All patients are with visual acuity (uncorrected, with habitual correction, 
and best spectacle correction). 
3. There is no restrictions on the range and regularity of keratometry. 
 
Exclusion Criteria: 
1. Patients with a history of any trauma to the eye. 
2. Patients with recent contact lens wear. 
3. History of ocular surgery. 
4. 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 antimetropic refraction. 
Topography Technique: 

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.
 
 
:
Ethical Considerations
 
 
 Informed consent will be taken from all cases' parents. 
 Ethical approval will be taken from the scientific ethics committee. 
 A written informed consent will be obtained from each participant 
patient. 
 Patients will be informed that Topography and all measurements done 
medically indicated. 
 
The study is submitted for evaluation and approval to the medical 
research ethics committee of the Sohag Faculty of Medicine. 
 
 
 

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