In order to solve the problems of difficult test, high cost and long cycle in the development of large-scale airborne negative pressure isolation system, the simulation analysis of negative pressure response characteristics is carried out around various aviation conditions such as aircraft ascending, leveling and descending, especially rapid decompression, based on the computational fluid dynamics (CFD) method. The results showed that the isolation cabin could achieve –50 Pa pressure difference environment and form a certain pressure gradient. The exhaust air volume reached the maximum value in the early stage of the aircraft’s ascent, and gradually decreased with the increase of altitude until it was level flying. In the process of aircraft descent, the exhaust fan could theoretically maintain a pressure difference far below –50 Pa without working; Under the special condition of rapid pressure loss, it was difficult to deal with the rapid change of low pressure only by the exhaust fan, so it was necessary to design safety valve and other anti-leakage measures in the isolation cabin structure. Therefore, the initial stage of aircraft ascent is the key stage for the adjustment and control of the negative pressure isolation system. By controlling the exhaust air volume and adjusting parameters, it can adapt to the change of low pressure under normal flight conditions, form a relatively stable negative pressure environment, and meet the needs of biological control, isolation and transport.
ObjectiveTo observe the optical coherence tomography angiography (OCTA) image characteristics of polypoid choroidal vascular disease (PCV) after intravitreal injection of anti-vascular endothelial growth factor drugs, and to discuss its significance in the diagnosis and follow-up of PCV.MethodsA retrospective case study. From August 2018 to January 2020, 22 eyes of 22 patients with PCV diagnosed in the ophthalmological examination of Affiliated Hospital of Weifang Medical University were included in the study. Among them, there were 10 males with 10 eyes and 12 females with 12 eyes; the average age was 67.75±9.53 years. Best corrected visual acuity (BCVA), OCTA, and indocyanine green angiography (ICGA) were performed. All the affected eyes were injected vitreously with 10 mg/ml Conbercept 0.05 ml (including Conbercept 0.5 mg) once a month for 3 consecutive months.Tthe macular area of 3 mm×3 mm and 6 mm×6 mm with an OCTA instrument was scanned, and the foveal retinal thickness (CRT) was measured, the area of abnormal branch blood vessels (BVN). pigment epithelial detachment before and 12 months after treatment (PED) height, foveal choroid thickness (SFCT) were performed. The diagnosis rate of PCV by OCTA was observed, as well as the changes of various indicators of BCVA and OCTA. Before and after treatment, BCVA and CRT were compared by paired t test; BVN area, PED height, and SFCT were compared by variance analysis. The changes in imaging characteristics of OCTA before and after treatment were analyzed.ResultsAmong the 22 eyes, 8 eyes were BVN; 5 eyes were polypoid lesions (polyps); 5 eyes were BVN combined with polyps; 3 eyes were not found with BVN and polyps; 1 eye with small vascular network structure, this eye was ICGA Appears as strong nodular fluorescence (polyps). The detection rate of PCV by OCTA was 86.36% (19/22). Twelve months after treatment, BVN was significantly reduced or disappeared in 16 eyes (72.72%, 16/22); polyps disappeared in 17 eyes (77.27%, 17/22). Compared with before treatment, 12 months after treatment, BCVA increased (t=3.071), CRT decreased (t=2.440), the difference was statistically significant (P＜0.05); the average BVN area, PED height, and SFCT decreased. The difference in average BVN area and PED height was statistically significant (F=2.805, 3.916; P＜0.05), and the difference in SFCT was not statistically significant (F=0.047, P＞0.05).ConclusionsThe detection rate of PCV by OCTA is 86.36%. After PCV anti-vascular endothelial growth factor drug treatment, BVN area decrease and polyps subside. OCTA is an effective means for PCV diagnosis and follow-up after anti-VEGF drug treatment.
Idiopathic intracranial hypertension (IIH) is a neurological disease, characterized by increased intracranial pressure and papilledema, and often associated with headache, transient loss of vision and pulsatile tinnitus. IIH typically occurs in women of childbearing age. Over 90.0% of patients are with obesity or over weighted. Loss of sensory visual function is the major morbidity associated with IIH and some patients even develop into blindness. Most patients will have varied degrees of visual impairment, or even a few become blind. Frisén grading system, visual field examination and spectral-domain optical coherence tomography can be used to evaluate and monitor the IIH papilledema functionally and morphologically. In recent years, IIH treatment trials in other countries confirmed that, weight loss and low-salt diet combined with acetazolamide treatment has a clear improvement for IIH patients with mild visual impairment. In-depth understanding of the etiology, clinical manifestations, diagnostic criteria and the main treatment has important clinical significance for IIH patients
PURPOSE:To inquire into diagnosis and differentiation method for full thickness macular hole,lamellar macular hole and cystoid macular degeneration. METHODS:Amsler grid,Watzke' s sign and laser aiming beam test were performed in the patients:30 with full-thickness macular hole, 12 with lamellar macular hole and 8 with cystoid macular degeneration. The results were analyzed statistically with method of four table precise probability. RESULTS:The positive rate of Amsler grid,watzke's sign and laser aiming beam test was 100% in ail of the full thickness macular holes,and it was 85%，65%and 0 in lamellar macular holes and cystoid macular degeneration respectively.
CONCLUSION: Amsler grid testing was sensitive but not specific,Watzke's sign was more sensitive and specific,and the laser aiming beam tesl was extremely sensitive and specific in clinical diagnosis of full thickness macular hole.
（Chin J Ocul Fundus Dis,1996,12: 208-210）
ObjectiveTo observe the protective effect of human umbilical cord blood stem cells (hUCBSC) transplantation on retinal ganglion cells (RGC) after optic nerve injury.
Method48 adult Sprague-Dawley rats were randomly divided into group A and B, therefore 24 rats in each group. Calibrated optic nerve crush injury model was induced in the left eyes, the right eyes served as a control. Medicine was injected at seventh day after optic nerve injury. PBS was injected into the eyes of Group A rats by peribulbar injection. The hUCBSCs were injected into the eyes of Group B rats by peribulbar injection. Seven days before sacrifice, 5% fluorogold was injected into superior colliculi bilaterally. At 7, 14, 21, 28 days after labeled, retinal flat mounts were observed under fluorescence microscope and optical microscope to investigate the morphological and RGC changes in density during retinal degeneration.
ResultsThe RGC number showed a tendency to decline gradually along with increases of the time in two groups, but the trend of decrease of Group B was evidently slower than that of Group A. The RGC number of the injury eye were less than the control eye in Group A and B (t=3.24, 3.15; P < 0.05). At 7, 14, 21, 28 days after labeled, the RGC number (t=4.78, 4.70, 3.98, 3.27; P < 0.05) and labeled RGC rate (t=4.39, 4.21, 4.36, 5.07; P < 0.05) in group B were more than those in group A. After optic nerve injury, there was karyopycnosis on ganglion cell layer of retina, thinning on each layer of retina, derangement of cell and decrease in RGC. There was different degree of the above change in different time after optic nerve injury. There were the swelling, the hemorrhage, derangement of spongiocyte and the denaturation like vacuole in the spot of optic nerve injury. Moreover, they were aggravating with increases of the time after optic nerve injury. There was no pathological changes in normal eyes.
ConclusionThe hUCBSC can increase the survival rate of the RGC and can rescue and(or) restore the injujed RGC after transplanted into body of optic nerve crush rat model by peribulbar injection.
Inherited retinal diseases (IRDs) are the major cause of refractory blinding eye diseases, and gene replacement therapy has already made preliminary progress in the treatment of IRDs. For IRDs that cannot be treated by gene replacement therapy, gene editing provides an alternative therapeutic method. Strategies like disruption of pathogenic variants with or without gene augmentation therapy and precise repair of pathogenic variants can be applied for IRDs with various inheritance patterns and pathogenic variants. In animal models of retinitis pigmentosa, Usher syndrome, Leber congenital amaurosis, cone rod cell dystrophy, and other disorders, CRISPR/Cas9, base editing, and prime editing showed the potential to edit pathogenic variations in vivo, indicating a promising future for gene editing therapy of IRDs.
Objective〓〖WTBZ〗To observe the clinical features of autoimmune optic neuropathy (AON). 〖WTHZ〗Methods〓 〖WTBZ〗The clinical data of 58 patients with AON from Jan. 2006 to Dec. 2007 were retrospectively analyzed. The patients had undergone routine ophthalmological, neurological examination, visual field test, all set of autoimmune antibody test, brain MRI. 〖WTHZ〗Results〓〖WTBZ〗In 93 eyes of 58 patients with AON, the lowest best corrected visual acuity (BCVA) was lt;01 in 68 eyes (731%), 10 patients (172%) had other symptoms of nervous system, 14 patients (241%) had lesions of nonneurological system. Positive antinuclear antibody was found in 43 patients (796%); other abnormal antibodies were also found, including antiSSA/SSB, antidsDNA, antihistonic, anticardiolipin, and antihuman leukocyte antigen B27 antibodies. Systematic connective tissue disease presented in 20 patients (345%), such as sicca syndrome, systemic lupus erythematosus, and Behcet disease. 32 patients (552%) had abnormal brain MRI, and the BCVA of 49 eyes (777%) improved significantly after hospitalization. 〖WTHZ〗Conclusion〓〖WTBZ〗Patients with AON always have poor visual function, some of whom associate with other systems, as well as damages to other parts of the nervous system. While some AON patients are secondary to systemic connective tissue disease involving the optic nerve, the majority of these patients are isolated autoimmune optic neuropathy.
ObjectiveTo observe the clinical features of familial exudative vitreoretinopathy (FEVR).
Methods202 FEVR patients (404 eyes) from 84 families were included in this retrospective study, all the clinical diagnosis was made by the same expert in our Department. All patients were examined with slit lamp microscope, indirect ophthalmoscopy, children's retinal imaging system or Heidelberg HR2 fundus cameras for fundus photographs. Fluorescein angiography (FFA) was also performed for all patients, for those≤7 years old it was performed under general anesthesia. Data collected from charts included gender, age at presentation and family history. According to the fundus presentation and FFA results, FEVR was classified into 0-5 stages. Stage 0 (normal) is for the health fellow eye in unilateral FEVR; stage 1: retinal peripheral avascular zone with no fluorescence leakage in FFA; stage 2: retinal peripheral avascular zone, with fluorescence leakage in FFA; stage 3: partial retinal detachment not involving the macular; stage 4: partial retinal detachment involving the macular; stage 5: total retinal detachment.
ResultsThere were 119 male patients and 83 females. The average age of diagnosis was 16 months, the average gestational age was 39 weeks and the average birth weight was 3223 g in the proband. At the first clinical visit, there was clear family history of FEVR in 4 patients (1.98%); family history of other eye disease (nystagmus, cataract, small eyes, strabismus and others) in 25 patients (12.38%); not family history of eye disease in 173 patients (85.64%). FEVR family history was confirmed by fundus examination and FFA for the family members. In all 404 eyes, 9 eyes (2.23%) was normal, 162 eyes (40.10%) was stage 1, 97 eyes (24.01%) was stage 2, 72 eyes (17.82%) was stage 3, 20 eyes (4.95%) was stage 4, and 44 eyes (10.89%) was stage 5. In 202 patients, 59 cases (29.21%) was asymmetry bilateral disease with different stage for each eye. In 404 eyes, retinal fold was found in 74 eyes (18.32%).
ConclusionsFEVR was common in full-term and/or normal birth weight newborns. More than half of patients are in stage 1 and 2 without any clinical features. 29.21% eyes were asymmetry bilateral diseases.
Due to their diverse types, complex causes, high incidence, and difficult treatment, lung diseases have become major killers threatening human life and health, and some lung diseases have a significant impact on alveolar morphology and histology. Numerical simulation of alveolar mechanical response, alveolar flow field information, multiphase flow, and material transport based on computational fluid dynamics is of great significance for lung disease diagnosis, clinical treatment, and in vitro experiments. Starting from the simplification and pathological differences of geometric and mechanical models, this paper analyzes and summarizes the conditions and application scenarios of the airflow dynamics calculation method in pulmonary alveoli, to provide a reference for further simulation and application of the alveolar region.
Acute coronary syndromes (ACS) are clinical syndromes caused by the instability or rupture of coronary atheromatous plaques. The development and treatment of ACS are closely related to some ocular manifestations. Hypertensive retinopathy, retinal arteriovenous occlusion, diabetes retinopathy, and age-related macular degeneration are associated with a high risk of ACS. Retinal vascular occlusion may be a potential postoperative complication of the percutaneous coronary intervention for ACS. Ocular parameters such as the retinal vascular diameter and density, the blood flow velocity of the ophthalmic artery, and the choroidal thickness are expected to be markers for assessing or predicting the risk of ACS, which are of important value for the prevention of cardiovascular events such as ACS.
