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Objective:To analyze and compare the corneal higher order aberration (HOA) after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE).Methods:A non-randomized controlled study was conducted.Sixty myopic patients (60 eyes) who underwent FS-LASIK or SMILE correction at Shandong Eye Hospital from April 2018 to January 2020 were enrolled and the data from the right eye were collected for analysis.Thirty cases (30 eyes) who received FS-LASIK in FS-LASIK group and 30 cases (30 eyes) who received SMILE in SMILE group had a preoperative equivalent spherical diopter of (-5.36±1.11)D and (-4.93±1.03)D, respectively.The HOA of the 6-mm anterior surface, posterior surface, and whole cornea were measured before surgery and at 1, 3, 6, and 12 months after surgery using Pentacam.The root mean square values (μm) of total corneal HOA, spherical aberration, coma and trefoil were obtained.Differences in the above root mean square values at different time points were compared between the two groups.The study protocol adhered to the Declaration of Helsinki and was approved by the Ethics Committee of Shandong Eye Hospital (No.SDSYKYY20180306). Written informed consent was obtained from each subject.Results:The preoperative and 1-, 3-, 6-, 12-month postoperative total HOA of the anterior corneal surface were (0.428±0.126), (0.775±0.169), (0.811±0.194), (0.759±0.214), (0.704±0.199)μm in the FS-LASIK group and (0.409±0.094), (0.656±0.148), (0.681±0.161), (0.668±0.175), (0.648±0.160)μm in the SMILE group, with a significant overall difference ( Fgroup=5.652, P=0.024; Ftime=107.169, P<0.01). Compared with SMILE group, the postoperative total HOA of anterior corneal surface and spherical aberration at different time points were increased in FS-LASIK group, showing statistically significant differences (all at P<0.05). Compared with before surgery, the postoperative total HOA of the anterior corneal surface and spherical aberration at different time points were increased in both groups, showing statistically significant differences (all at P<0.05). In the two groups, the 6- and 12-month postoperative total HOA of the anterior corneal surface were reduced in comparison with the 3-month postoperative ones of the anterior corneal surface, and the 12-month postoperative spherical aberrations of the anterior corneal surface were significantly reduced in comparison with the 1- and 3-month postoperative ones of the anterior corneal surface, showing statistically significant differences (all at P<0.05). There were significant differences in the coma and trefoil of the anterior corneal surface between before and after the operation (coma: Ftime=47.848, P<0.01; trefoil: Ftime=2.497, P=0.046). Compared with before surgery, the postoperative coma was significantly increased in the two groups (all at P<0.05). There were significant differences in total corneal HOA and spherical aberration at different postoperative time points between the two groups (total HOA: Fgroup=8.093, P=0.008; Ftime=125.019, P<0.01.spherical aberration: Fgroup=4.771, P=0.037; Ftime=34.033, P<0.01). Compared with SMILE group, the total corneal HOA and spherical aberration were significantly increased in FS-LASIK group at different postoperative time points (all at P<0.05). Compared with before surgery, postoperative total HOA of the anterior corneal surface and spherical aberration at different postoperative time points were significantly increased in both groups (all at P<0.05). In both groups, the 12-month postoperative corneal spherical aberration was significantly reduced in comparison with the 1- and 3-month postoperative ones (all at P<0.05). There was a significant difference in coma between before and after surgery ( Ftime=30.829, P<0.01). Compared with before surgery, the postoperative coma was significantly increased at different time points in both groups (all at P<0.05). Conclusions:Both FS-LASIK and SMILE increase the HOA of the anterior corneal surface and the whole cornea.Compared with FS-LASIK, SMILE introduces less HOA of the anterior corneal surface and the whole cornea as well as spherical aberrations.
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Objective:To evaluate and compare the safety, efficacy, stability and predictability of laser-assisted subepithelial keratomileusis (LASEK) with femtosecond laser assisted in situ keratomileusis (FS-LASIK) for high myopic eyes.Methods:A non-randomized controlled clinical study was performed.The clinical data of 141 eyes of 75 patients who received LASEK or FS-LASIK for high myopia in Shandong Eye Hospital from January 2013 to December 2016 with complete medical data during 1-year following-up.The 56 eyes with the preoperative diopter of (-8.29±1.64)D received LASEK (LASEK group), and the 85 eyes with the preoperative diopter (-7.97±1.38)D underwent FS-LASIK (FS-LASIK group). Pre- and post-operative best corrected visual acuity (BCVA) and post-operative uncorrected visual acuity (UCVA) were recorded, and the spherical equivalent was examined by subjective optometry.The efficacy index, safety index, refractive stability, predictability and complications were assessed 6 months and 12 months after surgery.Efficacy index was defined as postoperative UCVA/preoperative BCVA; safety index was postoperative BCVA/preoperative BCVA; refractive stability was the difference of spherical equivalent between postoperative 6 months and 12 months, and predictability was the percentage of the eyes with the diopter ≤±0.50 D after surgery.This study protocol was approved by the Ethic Committee of Shandong Eye Hospital (No.SDSYKYY20180130).Results:There were no significant differences in efficacy index and safety index in both LASEK group and FS-LASIK group at 6 months and 12 months after surgery (all at P>0.05). The spherical equivalent was (0.08±0.30)D and (0.10±0.38)D in the LASEK group and (0.00±0.32)D and (0.01±0.35)D in the FS-LASIK group at 6 months and 12 months after surgery, and there were no significant differences between different time points in both LASEK group and FS-LASIK group ( t=0.376, P>0.05; t=0.227, P>0.05), showing a good refractive stability.At 12 months after surgery, the percentage of the eyes with spherical equivalent within ±0.50 D was 91.1% in the LASEK group and 96.4% in the FS-LASIK group, there was no significant difference between the two groups ( χ2=1.838, P>0.05). Four eyes in the LASEK group developed corneal haze at 12 months after the operation, and the postoperative BCVA was less than the preoperative BCVA. Conclusions:Both LASEK and FS-LASIK are safe, effective, stable and predictable for the correction of high myopic eyes.Corneal haze after LASEK is the main reason for the loss of BCVA.
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Objective:To evaluate and compare the safety, efficacy, stability and predictability of laser-assisted subepithelial keratomileusis (LASEK) with femtosecond laser assisted in situ keratomileusis (FS-LASIK) for high myopic eyes.Methods:A non-randomized controlled clinical study was performed.The clinical data of 141 eyes of 75 patients who received LASEK or FS-LASIK for high myopia in Shandong Eye Hospital from January 2013 to December 2016 with complete medical data during 1-year following-up.The 56 eyes with the preoperative diopter of (-8.29±1.64)D received LASEK (LASEK group), and the 85 eyes with the preoperative diopter (-7.97±1.38)D underwent FS-LASIK (FS-LASIK group). Pre- and post-operative best corrected visual acuity (BCVA) and post-operative uncorrected visual acuity (UCVA) were recorded, and the spherical equivalent was examined by subjective optometry.The efficacy index, safety index, refractive stability, predictability and complications were assessed 6 months and 12 months after surgery.Efficacy index was defined as postoperative UCVA/preoperative BCVA; safety index was postoperative BCVA/preoperative BCVA; refractive stability was the difference of spherical equivalent between postoperative 6 months and 12 months, and predictability was the percentage of the eyes with the diopter ≤±0.50 D after surgery.This study protocol was approved by the Ethic Committee of Shandong Eye Hospital (No.SDSYKYY20180130).Results:There were no significant differences in efficacy index and safety index in both LASEK group and FS-LASIK group at 6 months and 12 months after surgery (all at P>0.05). The spherical equivalent was (0.08±0.30)D and (0.10±0.38)D in the LASEK group and (0.00±0.32)D and (0.01±0.35)D in the FS-LASIK group at 6 months and 12 months after surgery, and there were no significant differences between different time points in both LASEK group and FS-LASIK group ( t=0.376, P>0.05; t=0.227, P>0.05), showing a good refractive stability.At 12 months after surgery, the percentage of the eyes with spherical equivalent within ±0.50 D was 91.1% in the LASEK group and 96.4% in the FS-LASIK group, there was no significant difference between the two groups ( χ2=1.838, P>0.05). Four eyes in the LASEK group developed corneal haze at 12 months after the operation, and the postoperative BCVA was less than the preoperative BCVA. Conclusions:Both LASEK and FS-LASIK are safe, effective, stable and predictable for the correction of high myopic eyes.Corneal haze after LASEK is the main reason for the loss of BCVA.
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Computed tomography (CT) is an essential imaging modality. To solve the problem caused by increasing radiation exposure from CT scanner and to elevate the image quality, we aimed to apply the general objective image quality methods in CT image quality evaluation. After analyzing the perceptual features of CT image, we tested several popular objective image quality metrics, which focus on the similar perceptual features, on the CT image of phantom and animals. Experiments for verifying the feasibility were carried out. Compared with the subjective ratings from two professional radiation physicians, the complex wavelet-based structural similarity metric presents the better prediction results of the image quality.
Assuntos
Humanos , Simulação por Computador , Desenho de Equipamento , Processamento de Imagem Assistida por Computador , Controle de Qualidade , Doses de Radiação , Radiometria , Tomografia Computadorizada por Raios X , Padrões de ReferênciaRESUMO
BACKGROUND: Previous research has proved that olfactory ensheathing cells can promote neuronal survival and axonal regeneration. OBJECTIVE: To investigate the effect of olfactory ensheathing cell transplantation on the treatment of spinal cord injury of rats. METHODS: A total of 40 healthy adult female SD rats were randomly divided into control and cell transplantation groups, with 20 rats for each group. Ten additional SD rats were used for separation and culture of olfactory ensheathing cells. Spinal cord injury was induced in both control and cell transplantation groups. 2-cm bilateral 8th-10th intercostal nerves were crossly implanted into spinal cord defect region, i.e., proximal white matter and distal gray matter, distal white matter and proximal gray matter. Olfactory ensheathing cells at density of 2×10~6 were locally injected into cell transplantation group, while an equal amount saline was locally injected into control group. Somatosensory evoked potential and motion evoked potential were detected to observe neuro-electrophsiological recovery; BBB was used to evaluate hindlimb motor function; BDA anterograde tracer was used to observe motor conduction recovery. RESULTS AND CONCLUSION: Latency and amplitude of somatosensory evoked potential and motion evoked potential in the cell transplantation group were significantly greater than control group (P < 0.01). BBB scores of cell transplantation group were significantly greater than control group (P < 0.01). BDA-positive nerve fibers in the cell transplantation group were significantly more than control group (P < 0.01). Local injection of olfactory ensheathing cells can improve neuro-electrophysiological changes and promote hindlimb motor functional recovery following spinal cord injury.
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BACKGROUND:Brain injury is a serious central nervous system trauma.However,it is difficult to promote nerve regeneration and functional recovery after brain injury.Sheath cells are conducive to neuronal survival and axonal regeneration.OBJECTIVE:To explore feasibility and effect of olfactory ensheathing cells transplantation on rat brain injury.METHODS:A total of 90 healthy adult male SD rats were selected and 10 were used to prepare olfactory ensheathing cells.The remaining were randomly divided into model control and transplantation groups with 40 animals in each group.Model of middle cerebral artery occlusion was established by thread method.At 1 week,2×10~6 suspension of olfactory sheath cells and an equal volume of sterile saline were injected into two groups,respectively via the carotid artery.Neurological deficits were evaluated by creeping scores;histopathological changes were detected by HE staining,and glial fibrillary acidic protein and neurotrophic factor receptor p75 expression was detected by immunohistochemistry.RESULTS AND CONCLUSION:Compared with the model control group,the neurological deficit scores were significantly reduced in the transplantation group compared with the control group at 1,2,3,and 4 weeks following cerebral ischemia/reperfusion(P ＜ 0.05);the pathological changes in injured brain tissues were ameliorated,the number of nerve cell degeneration and necrosis was significantly reduced,and edema was attenuated.A great amount of glial fibrillary acidic protein and neurotrophic factor receptor p75 expression was detected in the infarct hemisphere following cell transplantation,and little in the contralateral hemisphere and vascular endothelial cells.Negative expression was detected in the model control group.Results show that the olfactory ensheathing cell transplantation is effective on ischemic brain injury in the rats.
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BACKGROUND: To improve neural regeneration and functional recovery following spinal cord injury (SCI) remains difficult. Embryonic neural stem cells benefit neuronal survival and promote axonal regeneration.OBJECTIVE: To explore the feasibility of the local injection of embryonic neural stem cells to treat rats with high level SCI, and evaluate its effect by neuroelectrophysiology and motor function of hind limbs.DESIGN, TIME AND SETTING: In vivo experiment of cytology was performed at the Animal Experimental Center of Harbin Medical University from June 2007 to June 2008.MATERIALS: A total of 40 healthy adult SD rats were randomly divided into two groups (n=20): normal saline and cell transplantation groups. In addition, 5 SD rats, pregnant 14 days, were used for preparation of embryonic neural stem cells.METHODS: High level SCI was made in two groups. Briefly, 2 cm of bilateral intercostal nerves respectively from the 8~(th) to 10~(th) costal bones was crossing implanted in the SCI (proximal white matter and distal gray matter; distal white matter and proximal gray matter). Cell transplantation group was locally injected with 2×10~6 embryonic neural stem cells, and normal saline group was injected with the same volume of normal saline.MAIN OUTCOME MEASURES: Somatosensory evoked potential (SEP) and motor evoked potentials (MEP) testing, observation of the recovery of neuroelectrophysiology; BDA anterograde neural tracer; the recovery of motor conduction by the main beam;BBB hind limb motor function score.RESULTS: SEP and MEP latency and amplitude of cell transplantation group were better than normal saline group (P < 0.01).BDA-positive nerve fibers through the tag were found in cell transplantation group, but no in normal saline group. BBB hind limb motor function score of cell transplantation group was significantly improved compared with normal saline group improved (P < 0.01).CONCLUSION: Local injection of embryonic neural stem cells betters neuroelectrophysiology and motor function of hind limbs following high level SCI.