Comparison of corneal thickness measurements using Galilei, HR Pentacam, and ultrasound.

PURPOSE: To assess the degrees of agreement in measuring corneal thickness in normal eyes between 2 noncontact systems based on the dual Scheimpflug system (Galilei; Ziemer) and rotating Scheimpflug imaging (HR Pentacam; Oculus) and also between each of these methods and the gold-standard method of ultrasound pachymetry. METHODS: In a prospective study, measurement agreement was assessed in 47 eyes of 47 healthy subjects. All eyes were examined with each of the 3 devices. Measurements made with the Galilei and HR Pentacam were compared with those made with ultrasound. The central corneal thickness (CCT) and thinnest pachymetry of the Galilei and HR Pentacam were also compared. RESULTS: The mean values of CCT obtained from Galilei, HR Pentacam, and ultrasound were 560.57 ± 29.10, 542.31 ± 30.50, and 548.61 ± 29.92 µm, respectively. The 95% limits of agreement of each of these devices with ultrasound were -11.03 and +34.94 µm for the Galilei and -33.67 and +20.74 µm for the Pentacam. The 95% limits of agreement of Galilei with Pentacam in measurement of central and thinnest corneal thickness were -3.39 and +33.11 and -10.40 and +27.29 µm, respectively. Although CCT measurements made with the HR Pentacam were thinner (P < 0.001), and those obtained with Galilei were thicker (P < 0.001) than those made with ultrasound, there were significant correlation between Galilei and ultrasound (r = 0.92; P < 0.0001) and between HR Pentacam and ultrasound (r = 0.89; P < 0.0001). The central and thinnest corneal thickness measurements made with the HR Pentacam were thinner (P < 0.0001) than those made with Galilei, but there was a significant correlation between Galilei and HR Pentacam in measuring CCT (r = 0.96; P < 0.0001) and thinnest corneal thickness (r = 0.95; P < 0.0001). Bland-Altman plots showed good agreement between these methods. CONCLUSIONS: Although differences between the devices were statistically significant, there was good correlation and agreement between Galilei and Pentacam in measuring central and thinnest corneal thickness. The corneal thickness measurements made with the HR Pentacam and Galilei also showed good correlation and agreement with those made with ultrasound.

Effect of Fas -670 A/G gene polymorphism on corneal allograft endothelial rejection.

BACKGROUND: Human cornea expresses functional Fas-ligand capable of killing Fas+ activated lymphocytes. Fas expression is partly regulated by -670 A/G polymorphism in the promoter region of Fas gene. OBJECTIVE: The aim of the present study is to determine the association between Fas-670A/G polymorphism and survival of corneal transplantation. METHODS: In 276 graft recipients who mainly underwent penetrating keratoplasty because of keratoconus, bullous keratopathy and corneal opacity, Fas -670 A/G polymorphism was determined by allele specific oligonucleotide polymerase chain reaction (ASO-PCR) techniques. RESULTS: There was no statistically significant relationship between Fas -670 A/G polymorphism and rejection episode (p=0.35). Moreover, the relationship between this polymorphism and rejection episode outcome (transplant recovery vs failure) was not statistically significant (p=0.13). CONCLUSION: The results of the present study show no significant correlation between corneal graft rejection, rejection recovery and Fas -670A/G gene polymorphism.

Amniotic membrane transplantation for primary pterygium surgery.

PURPOSE: To evaluate the outcomes of primary pterygium excision with adjunctive amniotic membrane transplantation. METHODS: In an interventional case series, consecutive patients with primary pterygia underwent surgical excision with transplantation of preserved amniotic membrane onto bare sclera. Patients were followed for at least 12 months and the results were evaluated in terms of recurrent pterygium growth and complications. RESULTS: Fifty eyes of 50 consecutive patients including 27 male and 23 female subjects with mean age of 43.36±10.88 years were operated. The pterygia extended onto the corneas for 4.69±1.2 (range 3 to 7) mm. Only one eye (2%) demonstrated recurrent pterygium growth which responded to subconjunctival mitomycin C injection. Another eye (2%) developed amniotic membrane retraction which eventually required a second transplantation leading to complete resolution. CONCLUSION: Primary pterygium excision with amniotic membrane transplantation is a safe and effective surgical technique with low recurrence rate.