Corneal epithelial profile in psoriasis patients with and without dry eye disease

Background Psoriasis is an immune-mediated systemic inflammatory disease in which corneal affection takes various forms such as dry eye disease (DED), punctate epithelial keratitis, and sterile corneal infiltrates. Purpose The aim of this study was to evaluate the corneal epithelial profile of psoriasis patients using anterior segment optical coherence tomography (AS-OCT). Patients and methods This is a cross-sectional analytic study that included 81 eyes: 39 eyes of 20 psoriasis patients and 42 eyes of 21 healthy age-matched and sex-matched controls. They were divided into three groups: psoriasis patients with dry eye disease (PDED), psoriasis patients without DED (PS), and healthy subjects (HS). AS-OCT was done to study the epithelial profile data of each eye and to correlate any finding with the disease activity evaluated by the Psoriasis Area and Severity Index score and disease extent. Results The PDED patients showed significantly lower central corneal thickness (CCT), higher central epithelial thickness (CET), and thicker inferior epithelium (P=0.004, 0.002, and 0.005, respectively). A significantly thinner superior epithelium was detected in the PS group compared with the PDED and HS groups (P=0.001 and 0.010, respectively). In addition, the topographic thickness variability (SD) and minimim–maximum were significantly higher in both the PDED and PS groups compared with the HS group (P<0.001). The CCT showed a significantly positive correlation with the tear breakup time (r=0.373, P=0.020), while the CET showed a significantly negative correlation with it (r=−0.331, P=0.040). The CET also had a significant positive correlation with disease duration (r=0.390, P=0.014) and disease extent (r=0.323, P=0.045). Conclusion AS-OCT has proved to be a valuable method for screening and detecting the corneal whole thickness and epithelial thickness abnormalities in psoriasis patients in the presence or absence of DED. The presence of thicker epithelium and thinner CCT were significant findings in the PDED, while in psoriasis patients without DED, superior epithelial thinning was the significant finding. A statistically significant high topographic thickness variability was detected in both groups compared with the controls.