ABSTRACT
BackgroundThe three-dimensional configuration of the nasolacrimal canal is highly variable with age,gender,and race.But enlargement of the nasolacrimal canal has sparsely been reported in the literature.Objective Computed tomography dacryocystography was performed in patients with unilateral congenital nasolacrimal duct obstruction and normal children to analyze the difference of bilateral nasolacrimal canal.MethodsThis is a retrospective study.Axial scanwith sagittalandcoronalreconstructionwas appliedin computedtomography dacryocystography.Diameters of bilateral nasolacrimal canal of 20 unilateral congenital nasolacrimal duct obstruction patients and 20 normal children were measured.Written informed consent was obtained from each child ' s parents before examination.ResultsThe lacrimal sac,nasolacrimal duct and the peripheral tissue were clearly exhibited by computed tomography dacryocystography.The diameters of the origination,the middle part and the distal end of affected nasolacrimal duct were(5.5±1.4),(5.3±1.2),(5.3±1.6) mm,and normal ones were(3.9±0.8 ),(3.5± 0.8 ),( 3.9± 1.3 ) mm,respectively.These results were statistically significant ( t =5.200,6.967,2.932,P＜ 0.05 ).There was no statistically significant difference in bilateral nasolacrimal canal of normal children (t =0.346,0.281,0.312,P＞0.05 ).Conclusions Computed tomography dacryocystography can image lacrimal passage and their peripheral tissues clearly.The affected nasolacrimal canal diameters of unilateral congenital nasolacrimal duct obstruction were much larger than the fellow sides.The pathogenesis of this phenomenon need much research.
ABSTRACT
Background There is multi-dimensional order of spatial stereopsis perception in human,however,current stereopsis examination is zero-order of position disparity.A multi-dimensional space perception model is very important for the detection of stereoacuity.Objective This study was to screen the deficit of zero-order,first-order,second-order multi-dimensional spatial stereopsis perception in amblyopia and strabismus children and to explore the association of zero-order,first-order,second-order spatial perception deficit.Methods Multidimensional spacial perception was examined in 79 children aged 4-14 years in Beijing Children' s Hospital.Nineteen normal children,19 children with ametropia amblyopia,12 children with anisometropic amblyopia,18 children with strabismus and 11 children with strabismus combined amblyopia were included this study.The random-dot and line spatial stereopsis perception in zero-order,first-order and second-order were examined with a new system of multidimensional space perception screening.Written informed consent was obtained from each subject or custodian before any ocular examination associated with this study.Results Absence of zero-order,first-order,second-order random-dot channel was found in 24 children (24/79,30.4％),18 children (18/79,22.8％) and 24 children (24/79,30.4％) respectively,with an average percentage of 27.9％.Absence of zero-order,first-order,second-order line channel was examined in 37 children (37/79,46.8％),37 children (37/79,46.8％),32 children (32/79,40.5％),with an average percentage of 44.7％.In the children with a deficiency of the zero-order spatial perception,the children who still remained the first-order or/and second-order spatial perception of random-dot accounted for 41.6％ and that of lines accounted for 43.2％.In children without deficiency of zero-order random-dot or lines spatial space perception,deficiency of first-order and/or second-order spatial perception was in 37.5％ children.Various order spatial perception deficiency was seen in children suffering from amblyopia or strabismus compared with normal group(P ＜ 0.05).Conclusions There exists spatial perception deficiency in children with amblyopia or strabismus.The patients with zero-order spatial perception absence partially remain a first-order or/and second-order spatial perception;while the patients with normal zero-order spatial perception might have first-order or second-order spatial perception deficiency.The multi-dimensional space perception model has a directive role for the training of visual information process and the treatment of spatial perceptual learning in children with amblyopia or strabismus.