Association of Changes in Thickness of Limbal Epithelial and Stroma with Corneal Scars Detected by High-Resolution Anterior Segment Optic Coherence Tomography

Abstract

Aim: To investigate the corneal central and limbal thickness in cornea scar patients using high resolution anterior segment-OCT (AS-OCT) and to determine the changes of the limbal region due to the corneal scar. Also to evaluate the tear film parameters in scar patients. Methods: Thirty patients with central corneal scar and 30 control subjects.The control subjects were healthy individuals who came to our clinic for routine ophthalmologic examination. were enrolled in this matched case-control study. Central epithelial thickness (ET), stromal thickness(ST) and limbal epithelial (LET) and stromal thickness(LST) were analyzed using high resolution AS-OCT. For the ocular surface evaluation; tear break-up time with standard fluorescein sodium sterile strip application, Schirmer test-I, Ocular Surface Disease Index Questionnaire, were performed. Results: The mean central ET of the patient group was 51.5±12.4 µm, the mean central ET of the control group was 59.2±9.0 µm. There was a a statistically significant difference between patients and controls (p=0.008). The mean LST of the patients was 747.9±115.7 µm, and the mean LST of the controls was 726.3±79.7 µm. There was a statistically significant difference between patients and controls according to BUT (P= 0.009), SCH (p=0.04).However, there was no significant difference between OSDI results of patients and controls (p=0.08). Conclusion: Corneal monitoring with high resolution AS-OCT is a simple, non-invasive, and useful technique for corneal scar patients. Cornea scars caused decreased epithelial thickness. This result could be associated with lower tear film parameters in scar patients. The scar length is associated with higher IOP values. Decreased limbal epithelium and increased limbal stromal thickness were detected in scar patients.