Chemokine CXCR-4 and cyclooxygenase-2 in the pathogenesis of pterygium

Background/aim: This study aimed to investigate the expression of chemokine receptor 4 (CXCR-4) and cyclooxygenase-2 (COX-2) in the epithelium and stroma of pterygium tissue in comparison with healthy conjunctiva. Materials and methods: The expression of CXCR4 and COX-2 was investigated by immunohistochemistry in the epithelium and stroma of the pterygium tissue of 29 eyes and compared with healthy conjunctival tissues. The correlation between CXCR4 and COX-2 expression as well as the correlation of these markers with the area of pterygium were evaluated statistically. Results: COX-2 staining scores were 1.75 ± 0.63 in the epithelium and 1.20 ± 0.62 in the stroma of the pterygium tissue. Mean CXCR-4 staining in the epithelium was 0.069 ± 0.37, whereas it was 5.0 ± 2.84 cells in the stroma. There was almost no staining of COX-2 and CXCR4 in the control samples. There was a strong positive correlation between the expression of CXCR-4 and COX-2 in the stroma of the pterygium. Conclusion: CXCR-4 and COX-2 may play important roles in the pathogenesis of pterygium.

Diurnal Alterations of Refraction, Anterior Segment Biometrics, and Intraocular Pressure in Long-Time Dehydration due to Religious Fasting.

PURPOSE: To investigate the effects of dehydration due to fasting on diurnal changes of intraocular pressure, anterior segment biometrics, and refraction. SUBJECTS AND METHODS: The intraocular pressures, anterior segment biometrics (axial length: AL; Central corneal thickness: CCT; Lens thickness: LT; Anterior chamber depth: ACD), and refractive measurements of 30 eyes of 15 fasting healthy male volunteers were recorded at 8:00 in the morning and 17:00 in the evening in the Ramadan of 2013 and two months later. The results were compared and the statistical analyses were performed using the Rstudio software version 0.98.501. The variables were investigated using visual (histograms, probability plots) and analytical methods (Kolmogorov-Smirnov/Shapiro-Wilk test) to determine whether or not they were normally distributed. RESULTS: The refractive values remained stable in the fasting as well as in the control period (p = 0.384). The axial length measured slightly shorter in the fasting period (p = 0.001). The corneal thickness presented a diurnal variation, in which the cornea measured thinner in the evening. The difference between the fasting and control period was not statistically significant (p = 0.359). The major differences were observed in the anterior chamber depth and IOP. The ACD was shallower in the evening during the fasting period, where it was deeper in the control period. The diurnal IOP difference was greater in the fasting period than the control period. Both were statistically significant (p = 0.001). The LT remained unchanged in both periods. CONCLUSIONS: The major difference was shown in the anterior chamber shallowing in the evening hours and IOP. Our study contributes the hypothesis that the posterior segment of the eye is more responsible for the axial length alterations and normovolemia has a more dominant influence on diurnal IOP changes.