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find Keyword "Threshold" 5 results
  • Photocoagulation and cryotherapy for prethreshold type 1 and threshold disease of retinopathy of prematurity

    ObjectiveTo evaluate the prognosis of photocoagulation and (or) cryotherapy for prethreshold type 1 and threshold disease of retinopathy of prematurity (ROP).MethodsThe data of 29 eyes of 15 infants who were diagnosed as with prethreshold type 1 or threshold disease of ROP from Jan 30th, 2003 to Jan 13th, 2005 were retrospectively analysed. Pre- and post-operative conditions of ROP were compared in the follow up. Any related local and systemic complications were recorded.ResultsIn 29 eyes which had undergone photocoagulation and (or) cryotherapy, ROP regressed completely in 19 (65.5%), remained dragged retina was found in 7 (24.1%), and retinal detachment was seen in 3 (103%). ROP regressed completely in 12 eyes (41.4%) after the initial treatment and in 7 eyes (24.1%) after the secondary treatment. During the treatment, temporary corneal haze was found in 2 eyes, vitreous hemorrhage occurred in 1 eye, and inadvertent photocoagulation at macular area happened in 1 eye. No systemic complications were found in all cases.ConclusionTimely treatment of photocoagulation and (or) cryotherapy for prethreshold type 1 and threshold disease of ROP may lead to famous prognosis.(Chin J Ocul Fundus Dis,2005,21:278-281)

    Release date:2016-09-02 05:52 Export PDF Favorites Scan
  • A study on the short-term fluctuation of macular light threshold in suspected early age-related macular dege-neration

    Objective To study the significance of detection the short-term fluctuation (SF) of macular light threshold detected by Octopus-123 automatic perimeter in suspected early age-related macular dege-neration (AMD). Methods SF of macular light sensitivity, Amsler chart and central visual acuity were examined in 51 patients(66 eyes) with suspected early AMD group and in 32 patients (40 eyes) in the control group. Results SF were significantly different in suspected early AMD group and control group. SF was more sensitive than the examination of central visual acuity and Amsler chart. SF was related to the quantity, location and quality of drusen. Conclusion Visual function of some suspected early AMD patients with drusen may be damaged, though the central visual acuity appears normal. (Chin J Ocul Fundus Dis, 2002, 18: 119-120)

    Release date:2016-09-02 06:01 Export PDF Favorites Scan
  • The comparison between tendency-oriented perimetry and traditional threshold perimetry

    Objective To evaluate the application of tendency-oriented perimetry (TOP) in detecting the visual function of glaucoma. Methods The traditional threshold perimetry (Normal/Normal strategy) and TOP (TOP/Normal strategy) carried out by Octopus 101 perimetry were used to examine the visual field of 20 normal subjects (20 eyes), 32 cases (32 eyes) of primary open-angle glaucoma (POAG), and 14 cases (14 eyes) of suspected POAG, respectively. The visual field outcomes, indices, point by point threshold variability and defective points of the two perimetries were compared and analysed. Results The negative rate of TOP was 90% in normal subjects. The positive rate of TOP was 75% in POAG , and 100% in middle and late stage of POAG. The visual field indices of two perimetries were positively correlated, with mean sensitivity (MS) of r=0.9335, mean defect (MD) of r=0.9189, and loss variance (LV) of r=0.9621. The point by point threshold variability and defective points of TOP were higher than those of traditional threshold perimetry, but the difference between the two perimetries was not significant (P=0.2019, P=0.4448). Conclusion The visual field indices of TOP and traditional threshold perimetry are positively correlated. The sensitivity and reproducibility of TOP are high in detecting the visual function of middle and late stage of POAG. (Chin J Ocul Fundus,Dis, 2002, 18: 269-272)

    Release date:2016-09-02 06:01 Export PDF Favorites Scan
  • To Optimize Perioperative Patient Blood Management

    The limitation of resource of blood and risk of transfusion-transmitted infections contribute to development and generalization of restrictive transfusion strategy. However, advanced evidences of clinical trials indicated a restrictive transfusion threshold after cardiac surgery was not superior to a liberal threshold with respect to morbidity or health care costs. It is time to optimize patient blood management but not free-transfusion and increase of risk of patients. The duration of red-cell storage was not associated with significant differences in the mortality and morbidity of patients. Three new pathogen-reduction technologies and pharmaceutical intervenes may provide safe of transfusion and improvement of outcomes.

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  • The application of regression discontinuity design in clinical therapeutic research

    The level of evidence in randomized controlled studies is high. However, it cannot be widely applied due to its high cost, external authenticity, ethics and other reasons. The traditional observational studies reduce the internal authenticity due to various confounding factors, and the level of evidence is low. Regression discontinuity design (RDD) is a design that observes and compares outcome of object around the threshold under practical clinical conditions. Its capability to adjust confounding factors is second only to that of randomized control studies. It can be used in cases where the intervention (or exposure) is directly related to the value of a continuous variable. For instance, whether an HIV patient needs antiretroviral treatment mainly depends on whether the CD4 cell count is lower than 200/μL. Because the measurement of continuous variables has random error, whether intervention is given near the threshold or is close to random, the baseline of patients in the intervention group and non-intervention group near the threshold should be balanced and comparable. Based on this assumption, the causal effect of intervention (or exposure) and outcome can be estimated by comparing the outcomes of populations near the threshold. RDD is mainly applicable to the study of classification outcomes in medicine, among which two-stage least square method, likelihood ratio based estimation method and Bayesian method are more commonly used model estimation methods. However, the application conditions of RDD and the requirement of sample size limit its extensive application in medicine. With the improvement of data accessibility and the development of real world research, RDD will be more widely used in clinical research.

    Release date:2018-11-16 04:17 Export PDF Favorites Scan
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