AIM:To investigate the foveal pit morphology changes in unaffected carriers and affected Leber’s hereditary optic neuropathy(LHON)patients with the G11778 A mutation from one family.METHODS:This study was a prospecti...AIM:To investigate the foveal pit morphology changes in unaffected carriers and affected Leber’s hereditary optic neuropathy(LHON)patients with the G11778 A mutation from one family.METHODS:This study was a prospective cross-sectional study.Both eyes from 16 family members(age from 9 to 47 y)with the G11778 A mutation were analyzed and compared with 1 eye from 20 normal control subjects.Eleven family members with the G11778 A mutation but without optic neuropathy were classified as unaffected carriers(n=22 eyes).Five family members(n=10 eyes)expressed the LHON phenotype and were classified as affected patients.Retinal images of all the subjects were taken by optical coherence tomography(OCT),and an automatic algorithm was used to segment the retina to eight layers.Horizontal and vertical OCT images centered on the fovea were used to measure intra-retinal layer thicknesses and foveal morphometry.RESULTS:Thicker foveal thickness,thinner foveal pit depth,and flatter foveal slopes were observed in unaffected carriers and affected LHON patients(all P<0.001).Further,the slopes of all four sectors in the LHON were flatter than those in the unaffected carriers(all P<0.001).Compared with the control group,affected LHON patients had a thinner retinal nerve fiber layer(RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),and total retina(all P<0.01).The retinal nerve fiber layer(RNFL)of affected patients was 38.0%thinner than that of controls while the GCL+IPL was 40.1%thinner.CONCLUSION:The foveal pit morphology shows changes in both unaffected carriers and affects patients.RNFL and GCL+IPL are thinner in affected LHON patients but not in unaffected carriers.展开更多
Frank’s theory describes that a screw dislocation will produce a pit on the surface,and has been evidenced in many material systems including GaN.However,the size of the pit calculated from the theory deviates signif...Frank’s theory describes that a screw dislocation will produce a pit on the surface,and has been evidenced in many material systems including GaN.However,the size of the pit calculated from the theory deviates significantly from experimental result.Through a careful observation of the variations of surface pits and local surface morphology with growing temperature and V/III ratio for c-plane GaN,we believe that Frank’s model is valid only in a small local surface area where thermodynamic equilibrium state can be assumed to stay the same.If the kinetic process is too vigorous or too slow to reach a balance,the local equilibrium range will be too small for the center and edge of the screw dislocation spiral to be kept in the same equilibrium state.When the curvature at the center of the dislocation core reaches the critical value 1/r0,at the edge of the spiral,the accelerating rate of the curvature may not fall to zero,so the pit cannot reach a stationary shape and will keep enlarging under the control of minimization of surface energy to result in a large-sized surface pit.展开更多
基金Supported by Wenzhou Technology Program(No.Y20160148).
文摘AIM:To investigate the foveal pit morphology changes in unaffected carriers and affected Leber’s hereditary optic neuropathy(LHON)patients with the G11778 A mutation from one family.METHODS:This study was a prospective cross-sectional study.Both eyes from 16 family members(age from 9 to 47 y)with the G11778 A mutation were analyzed and compared with 1 eye from 20 normal control subjects.Eleven family members with the G11778 A mutation but without optic neuropathy were classified as unaffected carriers(n=22 eyes).Five family members(n=10 eyes)expressed the LHON phenotype and were classified as affected patients.Retinal images of all the subjects were taken by optical coherence tomography(OCT),and an automatic algorithm was used to segment the retina to eight layers.Horizontal and vertical OCT images centered on the fovea were used to measure intra-retinal layer thicknesses and foveal morphometry.RESULTS:Thicker foveal thickness,thinner foveal pit depth,and flatter foveal slopes were observed in unaffected carriers and affected LHON patients(all P<0.001).Further,the slopes of all four sectors in the LHON were flatter than those in the unaffected carriers(all P<0.001).Compared with the control group,affected LHON patients had a thinner retinal nerve fiber layer(RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),and total retina(all P<0.01).The retinal nerve fiber layer(RNFL)of affected patients was 38.0%thinner than that of controls while the GCL+IPL was 40.1%thinner.CONCLUSION:The foveal pit morphology shows changes in both unaffected carriers and affects patients.RNFL and GCL+IPL are thinner in affected LHON patients but not in unaffected carriers.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11204009 and 61204011)the Beijing Municipal Natural Science Foundation,China(Grant No.4142005)
文摘Frank’s theory describes that a screw dislocation will produce a pit on the surface,and has been evidenced in many material systems including GaN.However,the size of the pit calculated from the theory deviates significantly from experimental result.Through a careful observation of the variations of surface pits and local surface morphology with growing temperature and V/III ratio for c-plane GaN,we believe that Frank’s model is valid only in a small local surface area where thermodynamic equilibrium state can be assumed to stay the same.If the kinetic process is too vigorous or too slow to reach a balance,the local equilibrium range will be too small for the center and edge of the screw dislocation spiral to be kept in the same equilibrium state.When the curvature at the center of the dislocation core reaches the critical value 1/r0,at the edge of the spiral,the accelerating rate of the curvature may not fall to zero,so the pit cannot reach a stationary shape and will keep enlarging under the control of minimization of surface energy to result in a large-sized surface pit.
