Measurements of orbital volume using cone-beam computed tomography in eye movement abnormalities.

PURPOSE: To measure the orbital volume in adult patients with unilateral eye movement abnormalities originating in childhood. METHODS: Cone-beam computed tomography was performed in 2 patients with eye movement abnormalities. A 28-year-old woman was treated because of right divergent squint originating at 8 years of age after penetrating corneal trauma. A 38-year-old man was examined because of abnormal head posture caused by left superior oblique underaction originating at 6 years of age. Orbital scans were analyzed with Cranioviewer 3D craniofacial cephalometric program. We measured bony orbital area in 6 slices (in ventro-dorsal direction per 4.8 mm) in every orbit on coronal scans. RESULTS: The volume was more in the orbit with unilateral divergent squint and less in the orbit with unilateral superior oblique underaction compared to the contralateral orbital volume measurements. CONCLUSION: Cranioviewer 3D craniofacial cephalometric program is suitable for volumetric analysis of the bony orbit on cone-beam computed tomography files. The development of the orbit can be influenced by extraocular muscle movements.

[Comparison of thickness values in nine macular subfields using time-domain and spectral-domain optical coherence tomography]. / Vastagságértékek összehasonlítása kilenc macularis mezoben time-domain és spectral-domain optikai koherencia tomográfiával.

AIM: To compare macular thickness measurements with spectral-domain (Cirrus HD-OCT) and time-domain (StratusOCT) optical coherence tomography. METHOD: Macular thickness was measured in nine ETDRS subfields in the same eye of 20 healthy subjects using both instruments. Using Cirrus HD-OCT both the Macular Cube 512×128 and Macular Cube 200×200 protocol, using StratusOCT the Fast Macular Thickness Map protocol was performed. Reproducibility of all three measurement series was assessed and the average of the measurement series was compared on each field. RESULTS: Measurement values obtained by StratusOCT were significantly lower than those obtained by Cirrus HD-OCT (p<0.001) in all subfields. Correlation coefficient between the results obtained by the two protocols of Cirrus HD-OCT was 0.977. CONCLUSIONS: By using Cirrus HD-OCT we could observe better repeatability than with StratusOCT. Using Cirrus HD-OCT significantly higher measurement values could be obtained in all subfields than those measured with Stratus. Using different OCT instruments we get significantly different values, therefore care needs to be taken when comparing data.

Time series models on analysing mortality rates and acute childhood lymphoid leukaemia.

In this paper we demonstrate applying time series models on medical research. The Hungarian mortality rates were analysed by autoregressive integrated moving average models and seasonal time series models examined the data of acute childhood lymphoid leukaemia.The mortality data may be analysed by time series methods such as autoregressive integrated moving average (ARIMA) modelling. This method is demonstrated by two examples: analysis of the mortality rates of ischemic heart diseases and analysis of the mortality rates of cancer of digestive system. Mathematical expressions are given for the results of analysis. The relationships between time series of mortality rates were studied with ARIMA models. Calculations of confidence intervals for autoregressive parameters by tree methods: standard normal distribution as estimation and estimation of the White's theory and the continuous time case estimation. Analysing the confidence intervals of the first order autoregressive parameters we may conclude that the confidence intervals were much smaller than other estimations by applying the continuous time estimation model.We present a new approach to analysing the occurrence of acute childhood lymphoid leukaemia. We decompose time series into components. The periodicity of acute childhood lymphoid leukaemia in Hungary was examined using seasonal decomposition time series method. The cyclic trend of the dates of diagnosis revealed that a higher percent of the peaks fell within the winter months than in the other seasons. This proves the seasonal occurrence of the childhood leukaemia in Hungary.

[Month of birth in childhood acute lymphoblastic leukemia]. / A születés idópontja gyermekkori lymphoid leukaemiában.

INTRODUCTION: An association between date of birth influenced by certain environmental factors (such as virus infections) and malignant diseases has been suggested in some previous papers. AIMS AND METHODS: The authors analyzed the birth dates of 814 children, 0-18 years of age, in whom acute lymphoblastic leukemia was diagnosed in the period between the 1st of January 1988 and 31st of December 2000. RESULTS: No association between month of birth and manifestation of leukemia in Hungarian children could be established. CONCLUSION: The results suggest that this approach was not capable of detecting any obvious prenatal environmental factors, including virus endemics, that could have influenced the appearance of leukemia.

Analysis of the time series for some causes of death.

The mortality data may be analysed by time series methods such as autoregressive integrated moving average (ARIMA) modelling. This method is demonstrated by two examples: analysis of the mortality data of cerebrovascular diseases and analysis of the mortality data of cancer of cervix. Mathematical expressions are given for the results of analysis. The relationships between time series of mortality rates were studied with ARIMA models. Calculations of confidence intervals for autoregressive parameters by tree methods: standard normal distribution as estimation and estimation of the White's theory and the continuous time case estimation. Analysing the confidence intervals of the first order autoregressive parameters we may conclude that the confidence intervals were much smaller than other estimations by applying the continuous time estimation model.