Discrete alpha-skew-Laplace Distribution

Classical discrete distributions rarely support modelling data on the set of whole integers. In this paper, we shall introduce a flexible discrete distribution on this set, which can, in addition, cover bimodal as well as unimodal data sets. The proposed distribution can also be fitted to positive and negative skewed data. The distribution is indeed a discrete counterpart of the continuous alpha-skew-Laplace distribution recently introduced in the literature. The proposed distribution can also be viewed as a weighted version of the discrete Laplace distribution. Several distributional properties of this class such as cumulative distribution function, moment generating function, moments, modality, infinite divisibility and its truncation are studied. A simulation study is also performed. Finally, a real data set is used to show applicability of the new model comparing to several rival models, such as the discrete normal and Skellam distributions

Discrete alpha-skew-Laplace Distribution

Classical discrete distributions rarely support modelling data on the set of whole integers. In this paper, we shall introduce a flexible discrete distribution on this set, which can, in addition, cover bimodal as well as unimodal data sets. The proposed distribution can also be fitted to positive and negative skewed data. The distribution is indeed a discrete counterpart of the continuous alpha-skew-Laplace distribution recently introduced in the literature. The proposed distribution can also be viewed as a weighted version of the discrete Laplace distribution. Several distributional properties of this class such as cumulative distribution function, moment generating function, moments, modality, infinite divisibility and its truncation are studied. A simulation study is also performed. Finally, a real data set is used to show applicability of the new model comparing to several rival models, such as the discrete normal and Skellam distributions

THE RESULTS OF RADIAL OPTIC NEUROTOMY FOR TREATMENT OF CENTRAL RETINAL VEIN OCCLUSION

"nCentral retinal vein occlusion (CRVO) is the third most common blinding vascular retinal disorder. As there is no proven treatment for CRVO, we performed this study to evaluate the effectiveness of radial optic neurotomy (RON) on visual acuity in eyes with CRVO. This study was designed as an interventional case series. Pars plana vitrectomy with RON was performed in 18 eyes of 16 patients with ischemic CRVO with visual acuities of 20/400 or less. Postoperative and preoperative visual acuities were compared using t paired test. Mean preoperative visual acuity was 20/1000 (range, 20/1600 to 20/630). Mean follow-up time was 3.6 months (range, 1 to 9 months). Mean postoperative visual acuity was 20/400 (range, 20/1600 to 20/50) at last follow-up and the difference was significant (P < 0.01; t paired test). Six patients (33%) improved to 20/200 postoperatively. There were no major complications intraoperatively. Chorioretinal shunts developed in neurotomy site in 9 cases (50%) 4 to 10 weeks after procedure which were associated with faster resolving of hemorrhage and venous dilation. There were no major complications noted with this procedure but vitreous hemorrhage and iris neovascularization was observed in the early postoperative period in 2 (11%) of 18 cases. RON may improve visual acuity in eyes with CRVO. It is a technically feasible and fairly safe procedure but postoperatively it may result in some complications such as vitreous hemorrhage, iris neovascularization and retinal detachment