Corneal Epithelial Mapping Among Healthy Egyptian Eyes of LASIK Age Group Using Spectral Domain Anterior Segment Optical Coherence Tomography

Abstract Background: A good knowledge of the corneal epithelium distribution may help a lot in many aspects of clinical work such as screening of keratoconus before corneal surgery, fitting contact lens, and increasing the accuracy of corneal refractive surgeries. Such compensatory epithelial changes are seen in cases of asymmetric LASIK flaps, flap malposition and irregular stromal surface following multiple refractive procedures. Aim of Study: To evaluate corneal epithelial thickness (CET) changes using Spectral domain-anterior segment optical coherence tomography (SD-AS-OCT) and to illustrate the distribution and variation of CET in healthy Egyptian eyes of LASIK age group (ranging from 18 to 50 years as long as the healthy condition of the cornea). Patients and Methods: This prospective descriptive cross-sectional study was performed to assess epithelial thickness data on a sample of the Egyptian population. This comprised 200 eyes from 100 healthy Egyptian adults (50 males and 50 females), whose ages ranged from 18 to 50 years. Subjects were recruited from the outpatient clinic of ophthalmology of Ain Shams University Hospitals from January 2020 to December 2020. Results: Our study demonstrated the epithelial layer of the cornea had a non uniform thickness profile, as suggested in previous studies. We found the thickest part was at inferior sector and the thinnest sector was superior. Our study showed the tear meniscus height was 300µm on average. This may influence the result of the corneal epithelium distribution especially the differences between different locations. Conclusion: Our study reports there was no statistically significant difference between males and females regarding epithelial thickness in different parts of the cornea.