Objective To evaluate the changes of diffusion kurtosis imaging (DKI) parameters with time in cerebral in farction patients,and contrast with diffusion tensor imaging (DWI).Methods DWI and DKI scans were performed in 95 patients of cerebral infarction.The patients were divided into five groups according to the time of cerebral infarction:Hyperacute phase (n=10),acute phase (n=12),early subacute phase (n =33),late subacute phase (n =20) and chronic phase (n =20).Parameters of DKI were obtained,and the parameters and percentage change of diffusion metrics from normal to ischemic tissue were compared.The evolution rule of parameter with time was analyzed.Results Mean kurtosis (MK),axial kurtosis (K//),radial kurtosis (K⊥) of DKI parameters increased after infarction,and reached the peak at acute phase,and decreased gradually with the prolonging of time.Mean diffusion (MD),axial diffusion (D//),radial diffusion (D⊥) of DTI parameters decreased after infarction,and reached the lowest at the acute phase,and increased gradually with the prolonging of time.The percentage change of MK,K//,K⊥ were higher than those of MD,D//,D⊥,and percent change along the axial direction were significantly larger than that along the radial direction.Conclusion DKI is superior to DTI in evaluating cerebral infarction,and can analyze the changes of microstructure of cerebral infarction comprehensively.

Objective: To compare the visual quality after topography-guided customized femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and wavefront-optimized FS-LASIK treatment in myopic eyes. Methods: A non-randomized controlled clinical study was performed.Seventy-eight eyes of 39 myopic patients undergoing FS-LASIK in Beijing Tongren Hospital from October 2016 to February 2017 were enrolled in this study and divided into two groups according to each patient's opinion, with matched demography between the two groups.Topography-guided customized FS-LASIK was performed on 42 eyes of 21 myopia in the topography-guided group, and wavefront-optimized FS-LASIK was performed on 36 eyes of 18 patients in the wavefront-optimized group.Visual acuity, refractive error, higher order aberrations (HOAs) and contrast sensitivity(CS) were compared between the two groups before and 6 months after surgery.Written informed consent was obtained from each patient before the operation.This study protocol was approved by Ethic Committee of Beijing Tongren Hospital (No.TRECKY2014-026). Results: The postoperative uncorrected visual acuity (UCVA) levels were eaqual to or better than the preoperative best corrected visual acuity (BCVA) in 95.2% patients in the topography-guided group, and in 94.4% patients in the wavefront-optimized group 6 months after surgery, respectively.There were no significant differences in the spherical equivalent, sphere refraction and cylinder refraction between the two groups (all at P>0.05). The amount of induced coma was significantly lower in the topography-guided group than that in the wavefront-optimized group ([0.07±0.22]μm vs.[0.22±0.16]μm) at 6 mm pupil.LogCS improved under the 12.0 c/d in the background of mesopic in the topography-guided group and decreased under the 18.0 c/d both in the background of mesopic and mesopic + glare in the wavefront-optimized group 6 months after surgery, with signifcant differences between them (all at P<0.05). LogCS values under 6.0, 12.0 and 18.0 c/d in the background of mesopic and 18.0 c/d in the background of mesopic+ glare in the topography-guided group were significantly higher than those in the wavefront-optimized group 6 months after surgery, with significant differences between the two groups (all at P<0.05). Conclusions Topography-guided FS-LASIK has lower higher-order aberrations and better CS than wavefront-optimized FS-LASIK.

Objective This study was to evaluate the long-term clinical efficiency of allogeneic corneal intrastromal lenticule inlay for correction of moderate and high hyperopia.Methods A prospective self-controlled case series study was adopted.Twenty-nine hyperopic patients (53 eyes) were performed with allogeneic corneal intrastromal lenticule inlays.The range of preoperative spherical equivalent was +3.75 to + 10 D,with the mean value of (+6.84±2.95)D.All the cases were followed up for 1 year.Uncorrected and best corrected visual acuity and refraction were compared between before and after operation.Corneal topography and optical coherence topography were used to examine corneal topography.Ocular response analyzer was used to evaluate the shifts of corneal hysteresis.This study followed the Helsinki declaration,and the research process was approved by the Ethic Committee of Beijing Tongren Hospital,and informed consent was signed by each donor and receptor.Results Compared with the before surgery,the uncorrected distance visual acuity (UDVA) and uncorrected near visual acuity (UNVA) were obviously improved and the spherical equivalent (SE) was obviously decresed in 3 months,6 months and 1 year after surgery,with significant differences between them (all at P＜0.05),but no significant differences were found between each postoperative time points (all at P＞0.05).One year after surgery,14 eyes (26.4％) gained one line of best corrected distance visual acuity (BCDVA),and 12 eyes (22.6％) gained two lines of BCDVA.Only 2 patients (5.66％) lost lines due to opaque lenticules,and no eye lost lines after changing the opaque lenticules.There was no obvious hyperopic fallback phenomenon.Compared with the before surgery,the average corneal curvature value (Avek) was obviously improved,the surface regularity index (SRI),surface asymmetry index (SAI) and central corneal thickness (CCT) were obviously increased in 3 months,6 months and 1 year after surgery,with significant differences between them (all at P＜0.05),but no significant differences were found between each postoperative time points (all at P ＞ 0.05).The cornea optical coherence tomography (OCT) examination showed that,after the operation,the corneal stromal implant was in place and clear.One year after surgery,the dividing line of corneal graft was still clearly visible.No significant changes of corneal hysteresis (CH) and corneal resistance factor (CRF) were seen among different time points before and after surgeries (F =1.443,P =0.216;F =1.744,P =0.128).Conclusions Allogeneic corneal small incision intrastromal lenticule inlays can be used to correct moderate and high hyperopic eye with good safety,effectiveness and predictability.It provides a new choice for hyperopic patients.