Comparison of multimetric D index with keratometric, pachymetric, and posterior elevation parameters in diagnosing subclinical keratoconus in fellow eyes of asymmetric keratoconus patients

Purpose To compare the multimetric D index and other keratoconus-screening parameters in patients with clinical keratoconus in 1 eye and subclinical keratoconus in the fellow eye. Setting Medipol University Hospital and Birinci Eye Hospital, Istanbul, Turkey. Design Retrospective case-control study. Methods Patients with clinical keratoconus in 1 eye and subclinical keratoconus in the fellow eye and eyes of normal subjects were evaluated with a rotating Scheimpflug imaging system (Pentacam). Parameters included anterior curve analysis, keratometry (K) values, minimum corneal thickness, pachymetric progression index, Ambrósio relational thickness, posterior elevation, back difference elevation, and D-index values. The receiver operating characteristic (ROC) curves were analyzed to evaluate the area under curve (AUC), sensitivity, and specificity of each parameter. Results Forty-five patients and 67 normal subjects were evaluated. The pachymetric progression indices, posterior elevation, and the D-index measurements were statistically significantly higher whereas corneal thickness and Ambrósio relational thickness measurements were significantly lower in eyes with keratoconus or subclinical keratoconus than in eyes of normal subjects (P <.05). Using the ROC analysis, the AUC values of the mean steep K, minimum corneal thickness, pachymetric progression index minimum, Ambrósio relational thickness maximum, posterior elevation, back difference elevation, and D index to distinguish between subclinical keratoconus from control subjects were 0.52, 0.64, 0.71, 0.72, 0.71, 0.76, and 0.83, respectively. Conclusion The new multimetric D index seems to be better than other single-metric parameters in diagnosing keratoconus and subclinical keratoconus with good specificity. However, the sensitivity levels of all parameters were relatively limited in the diagnosis of subclinical keratoconus. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned. © 2015 ASCRS and ESCRS

A New Species Of The Genus Aegla From Paraiba River Basin, Brazil

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Investigation for Remediation of Selenium Aqueous Environment with Using Organic Pillared Bentonite by Radiotracer Technique

In this study remediation of selenium ions from aqueous solutions was investigated using organic pillared bentonite as an adsorbent. Organic pillared bentonite was produced from Resadiye (Tokat, Turkey) bentonite using hexadecylpyridinium chloride and aluminum polyoxy-cations. All the experiments were carried out by tracing with selenium radioisotope. For the production of the radioactive selenium radioisotope, selenium dioxide was irradiated in the central thimble of ITU TRIGA Mark II Training and Research Reactor at Energy Institute of Istanbul Technical University. Radioactivity measurements carried out by the gamma-ray spectroscopy system were used to determine of selenium isotope. The relative importance of test parameters like concentration of adsorbate, pH of the solution and contact time on adsorption performance of organic pillared bentonite for selenium ion was studied. Evaluation of experiments for different parameters showed possibility of remediation of selenium from aqueous media by using organic pillared bentonite