Mohamad Aghazade Amiri, Mozhgan Alvandi , Seyed-Mohammad Naser Hashemian , Seyed-Mahdi Tabatabai ,
Volume 73, Issue 4 (7-2015)
Abstract
Background: In this study were focused on corneal cells changes in keratoconus disease, as there are differences between results of other studies that were done on keratokonic eyes. And the chief purpose was a comparison between keratoconus and normal population based corneal endothelium (in cell density, pleomorphism and polymegethism of cells).
Methods: This study is an observational study and is a case-control type. This study was done in Farabi Ophthalmology Hospital, Tehran, from September 2013 to February 2014. In this study, 26 mild (corneal power is lower than 48 diopter) and moderate (corneal power is between 48 to 54 diopter) keratoconic eyes (case group) with no history of contact lenses wear or eye surgeries were compared with 25 normal eyes (control group) that corneal power based topographic images is lower than 47.2 diopter. This comparison were done based specular microscopy images which were taken by Noncontact (Topcan Sp-2000 P) specular microscope in 5 corneal regions (central, superior, inferior, nasal, temporal). Then the information related to the cell density, Coefficient of Variation (CV) of polymegethism and pleomorphism of cells were analyzed by SPSS software, version 21 (SPSS, Inc., Chicago, IL, USA).
Results: Superior corneal region has the largest amount of endothelial cell density in case and control groups (P<0.001). But the effects of keratoconus on the cell density was not significant (P=0.96). And also CV of polymegethism in two groups (case and control groups), was similar (P=0.828). Pleomorphism was seen in 7 eyes of 26 eyes in case group (26.9%) and 6 eyes of 25 eyes in control group (24%).
Conclusion: Keratoconus does not have any considerable effect on cell density, polymegethism and pleomorphism, in mild and moderate stages and corneal opacity risk caused by intraocular surgeries (such as: Cataract or Glaucoma surgeries) and some diseases (such as diabetes and uveitis) is similar in keratoconic and normal eyes.
Sara Jambarsang , Alireza Akbarzadeh Baghban , Seyed Saeed Hashemi Nazari, Farid Zayeri , Ali Nikfarjam ,
Volume 73, Issue 9 (12-2015)
Abstract
Background: After primary infection, the number of CD4 T-cells decreases with disease progress. The patient’s immunological status could inform by The CD4 T-cell counts over the time. The main purpose of this study is to assess the trend of CD4 cell count in HIV+ patient that received Antiretroviral Therapy (ART) by using a multistate Markov model to estimate transition intensities and transition probabilities among various states.
Methods: A total of 122 HIV+ patients were included in this cohort study who are undergoing Antiretroviral Therapy treatment in the Iran AIDS center in Imam Khomeini Hospital in Tehran that inter during March 1995 to January 2005 and then fallow up to October 2014. All adults with at least two follow-up visits in addition to their pre-ART treatment were considered to be eligible for inclusion in the study. Continuous-time Markov processes are used to describe the evolution of a disease over different states. The mean sojourn time for each state was estimated by multi state Markov model.
Results: Sample included 22 (18%) female with a mean age of 43.32 (standard deviation 8.33) years and 100 (82%) male with a mean age of 45.28 (standard deviation 8.34) year. Age was divided in to two categories, 40 years old and lower than that 66 (54.1) patents and persons older than 40 years old 56 (45.9) patents. A total of 122 patients were included. 29 patients died during follow-up. One year transition probability for staying in state 1 of CD4 cell count was 51%. This probability for six year was 33%. The mean sojourn time for sate 4 was 21 month. The hazard ratio of transition from state 3 to state 4 was 4.4 in men related to women.
Conclusion: The use of antiretroviral therapy in the treatment of HIV infected persons reduce viral replication and increase in CD4 T lymphocyte count, and delay the progression of disease. This paper is shown the progression of this trend.
Mahsa Nazari, Farid Zayeri , Seyed Saeed Hashemi Nazari , Sara Jambarsang, Ali Nikfarjam , Alireza Akbarzadeh Baghban ,
Volume 77, Issue 2 (5-2019)
Abstract
Background: The Multi state Markov models have extensively application with categorization of laboratory marker of CD4 cells for evaluation of HIV disease progression. These models with different states result in different effects of covariates and prediction of HIV disease trend. The main purpose of this study was comparison of four and five states models with the three- state in order to select the model with better prediction ability of occurrence of HIV and finally death in HIV positive people.
Methods: A total of 305 HIV positive people were included in this cohort study in the Iran AIDS center in Imam Khomeini Hospital in Tehran that entered during March 1995 to January 2005 and then fallowed up to October 2014. The three continuous- time Markov models of three-, four- and five- state models were fitted to data to describe the evolution of a HIV disease Trend over different states.
For comparison of models, two criteria of modification of Akaike’s criterion (DRAIC) and likelihood cross-validation criterion (DRLCV) along with their 95% tracking interval was used. For fitting of these models and estimation of transition matrix and the hazard ratio of gender and treatment independent variables, the msm package of R project for statistical computing, version R 3.2.4 (www.r-project.org) was used.
Results: The results showed that the four- state model has more prediction ability than five-state model for evaluation of HIV disease Trend. In the four-state model, the progression hazard ratio to death for people who received highly active antiretroviral therapy (HAART) was 0.64 lower than who didn’t get this therapy. Moreover, the progression hazard ratio for men was 2.33 fold in comparison to women. The disease progression hazard ratio to death was 4.9 fold for men in comparison to women.
Conclusion: The (DRAIC) and (DRLCV) criterions showed that the four-state model has more predictive ability of the progression trend of HIV disease in comparison of five-state model.
