Analysis of the children's dynamic and static stereopsis of intermittent exotropia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To compare and analyze the stereopsis of intermittent exotropia children under the different backgrounds of dynamic stimuli and static stimuli. METHODS: We collected 56 children ( male 26, female 30 with intermittent exotropia at the age from 5y to 12y and examined their stereopsis under the different backgrounds of dynamic stimuli and static stimuli using a multidimensional sense perception training software. The differences between the dynamic stereopsis and static stereopsis were compared. RESULTS: Totally 17 cases ( 30%) had both dynamicstereopsis and static stereopsis, 39 cases ( 70%) had either dynamic or static stereopsis deficit, only 10 cases ( 26%) had dynamic stereopsis, 25 cases ( 64%) static stereopsis left and 4 cases ( 10%) were without any form of stereopsis. The positive rate of dynamic stereopsis was better than the positive rate of static stereopsis, with statistical significance (P CONCLUSION: Dynamicstereopsis is better than the static stereopsis to intermittent exotropia children.

Regulation of retinoic acid on permeability of retinal pigment epithelial barrier in lens-induced myopia / 中华实验眼科杂志

Background Retinal retinoic acid (RA) plays an important role in the formation of the lensinduced myopia.However,it is not clear how RA transfer the myopic signal to choroid throughout the retinal pigment epithelium (RPE) barrier.Objective The aim of this study was to investigate the effect of all-trans retinoic acid (atRA) on the barrier of RPE in lens-induced myopic eye of guinea pig.Methods Thirty left eyes of 30 21-dayold clean guinea pigs were randomized into normal control group and the model group.The models of out of focus were induced by covering of-6.00 D concave lens on the left eyes for 15 days.Radius of corneal curvature was measured using corneal curvimeter,and diopeter of the guinea pig was examined by mydriatic optometry.The length of ocular axis was detected by A-sonography.The animals were sacrificed and the retinas of the left eyes were isolated for the culture and passage of RPE cells.The third generation of cells were incubated Millcell-PET microporous film,and atRA at the concentration of 1 × 10-6,1 × 10-7,1 × 10-8 and 1 × 10-9 mol/L was added to the micropore respectively for 12 hours,and the micropores with equal-solvent served as negative control group.Methyl thiazolyl tetrazolium (MTT)colorimetric method was used to detect the survival rate of the cells.Subsequently,the transepithelial electrical resistance (TER) of the monolayer cells was determined with CN10-EVOM2 resistance measuring meter.The vesicular transport change of RPE membrane in different groups was evaluated by FM1-43 fluorescence staining.Results The mean diopter was (-2.20±0.95) D in the models,and that in the controls was (+ 1.15 ±0.30) D,with a significant difference between them (t =14.57,P＜ 0.01).The axial length was (8.24 ± 0.09) mm in the models and it was significantly longer than (7.81±0.05) mm in the controls (t=17.20,P＜0.01).RPE cells grew well to form a monolayer in Millcell culture pool after one week.After 24 hours of the atRA treatment,the survival rate of RPE cells reduced gradually with the increase of atRA concentration with the highest rate in the 1 × 10-9 mol/L atRA group (93.3 ％) and followed by the 1 × 10-8 mol/L atRA group (88.2％).More than half of the cells dead in the 1 × 10-6mol/L and 1 × 10-7mol/L atRA groups (53.8％ and 47.1％).Significant differences in the TER value and fluorescence staining intensity of the cells were seen among the various groups (F =43.89,P =0.00 ; F =26.13,P =0.00),with the maximal values in the 1 × 10-8mol/L atRA group.The FM1-43 fluorescence located on the cellular membrane and cytoplasm.Conclusions AtRA can increase the functional state of tight junction and vesicular transport,which regulated the RPE cell barrier in the guinea pig.

Antisense c-fos oligonucleotides-induced myopia in guinea pigs / 中南大学学报(医学版)

OBJECTIVE@#To characterize the antisense c-fos oligonucleotides that control the expression of immediate-early gene c-fos in retina in order to better understand the mechanism by which antisense c-fos oligonucleotides induced myopia. In this study the signal transduction in the pathway linking visual experience and the regulation of the eye's growth was investigated.@*METHODS@#Thirty-one 3-week guinea pigs were assigned into 3 groups: antisense and sense c-fos oligonucleotides were intravitreally injected every 3 days to the eyes of the experimental guinea pigs at different concentrations; and saline vehicle to control guinea pigs in the same way. The refraction and axial length of the eyes were measured before and after the treatment, and the immediate-early gene c-fos expression in the retina was quantified by immunohistochemistry and RT-PCR.@*RESULTS@#The moderate myopia was induced in high (1 nmol) and low (0.1 nmol) level of antisense c-fos oligonucleotide intravitreous injection (-5.425 D and -5.575 D, respectively) compared with the control ateral eyes. The refraction and axial length of the treated eyes increased, and the expression of immediate-early gene c-fos decreased significantly in the antisense c-fos oligonucleotides intravitreously injected eyes compared with the sense c-fos oligonucleotide intravitreously and saline vehicle injected eyes (P0.05).@*CONCLUSION@#The obvious myopia can be induced by antisense c-fos oligonucleotides in guinea pigs; antisense c-fos oligonucleotides inhibit c-fos expression in the retina. Immediate-early gene c-fos may be a potential factor in the prevention of myopia and plays an important role in the signal transduction of the retina.

High myopia and retinal ultrastructure of albino guinea-pigs / 中南大学学报(医学版)

OBJECTIVE@#To explore the relationship between melanin synthesis and the congenital high myopia of albino guinea-pigs.@*METHODS@#Twelve albino guinea-pigs and 12 pigmented guinea-pigs of 220~250 grams (aged 5~6 weeks) were chosen at random. The eyes were examined with retinoscopy, A-scan ultrasonography and vernier caliper. The retinal structures were examined with light and electronic microscope.@*RESULTS@#The diopter was -19.17 D in albino guinea-pigs and +0.63 D in pigmented guinea-pigs on average. Compared with the pigmented guinea-pigs, the axial dimensions of the albino guinea-pigs were elongated. There was significant difference between the albino guinea-pigs and the pigmented guinea-pigs. The retinal thickness, pigment granules and membrane disc of the outer segment of the visual cells decreased in the albino guinea-pigs, and the membrane disc space became narrow. The normal retinal thickness, plenty of pigment granules , membrane disc and wide membrane disc space could be observed in the pigmented guinea-pigs.@*CONCLUSION@#Albino guinea-pigs have high myopia, and pigmented guinea pigs have light hyperopia. There are structural differences in the retina between albino guinea-pigs and pigmented guinea-pigs. The abnormity of albino guinea-pigs provides optical foundation for its high myopia.

Apoptosis and c-myc protein expression in the retinal of form-deprivation myopia / 中南大学学报(医学版)

OBJECTIVE@#To study the apoptosis of retina and the expression of c-myc protein in form-deprivation myopia.@*METHODS@#Two-day-old chickens were sutured with right eyelid for 4, 8 and 12 weeks. After measurement of refracation, the eyeballs were observed by light microscope and taken photos. Retinal apoptotic cells were measured by TUNEL staining and flow cytometry. C-myc protein were examined by immunohistochemistry and flow cytometry.@*RESULTS@#Lacquer crack lesions were found in sutured eyes at 12 weeks. Apoptotic cells were observed in retinal outer and inner nuclear layer of the sutured eyes at 12 weeks and obvious peak of apoptosis was observed in sutured eyes at 12 weeks. The expression of c-myc protein was significantly more than control eyes at 8 and 12 weeks.@*CONCLUSION@#The apoptosis of retinal was present in form-deprivation myopia with the degeneration of retina. C-myc protein plays an important role in retinal apoptosis of myopia.

Dynamic expression of VIPR2 in form deprivation myopia / 中南大学学报(医学版)

OBJECTIVE@#To investigate the dynamic expression and significance of vasoactive intestinal peptide receptor 2 (VIPR2) on retina-choroid-clera in high myopia.@*METHODS@#Twenty-one yellow chicks of 1 day old were used in the research. The right eyes were the experimental group, covered continuously for 1 week, 2 weeks and 4 weeks respectively. The left eyes were not covered as the normal control group. Both groups were detected diopter degrees using retinoscopic refraction, determinated eyeball axis using ophthalmology ultra-A, and investigated VIPR2 expression on retina-choroid-sclera in both groups at three stages by SP immunohistochemical staining.@*RESULTS@#The experimental eyes changed from hypermetropia at pre-experiment to high myopia during the experiment stages, and the diopter degrees were deeper and eyeball axis was longer along with the period of being covered. Both groups had strong expression of VIPR2 on photoreceptor-outer segment of the retina and choroids. The expression was down-regulated with the time in both groups. Compared with the control group, VIPR2 expression of the experimental group was significantly up-regulated (P < 0.05).@*CONCLUSION@#Form deprivation could induce high myopia. The expression of VIPR2 existed on photoreceptor-outer segment of the retina and choroids. VIPR2 may play an important role on the formation and development of myopia.

Dynamic changes of MMP-2 activity in the posterior sclera of chicks with form-deprivation myopia / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of form-deprivation on level of gelatinase in the posterior sclera in chicks.@*METHODS@#Fifty 1-day-old chicks were monocularly deprived to establish the animal model of form-deprivation myopia (FDM). According to the duration of form-deprivation the experimental chicks were divided randomly and equivalently into 5 groups, which were deprived for 3, 7, 14, 21 and 30 days respectively. Meanwhile the other eyes of the deprived chicks were used as self-control groups and chicks of the same days were chosen randomly as the normal control groups for each FDM group. At each form-deprivation point the changes of degree of diopters and axial length of chicks in each group were recorded. The levels of gelatinase in posterior sclera of the experimental eyes were measured by gelatin enzymography.@*RESULTS@#Compared with the normal and self-control groups, the levels of MMP-2 activity in FDM groups were much higher (P <0.01). With the increase of the time of monocular deprivation these changes became more significant and reached the top after 14 days' deprivation with an inter-group statistical difference (P <0.01). The dynamic changes of MMP-2 activity were the same as those of axial length and degree of diopters in each experimental groups. There was positive correlation between the MMP-2 activity and axial length (r = 0.989, P < 0.01). But there was a negative correlation between the MMP-2 activity and refractive degree.@*CONCLUSION@#Increase of MMP-2 activity in the posterior sclera of chicks would be a direct key factor to trigger sclera ECM remodeling process in chick FDM.