Mechanism of the DL-alpha-aminoadipic acid inhibitory effect on form-deprived myopia in guinea pig.

AIM: To investigate the effect of intravitreal injection of DL-alpha-aminoadipic acid (DL-α-AAA) on ocular refractive state and retinal dopamine, transforming growth factor-ß2 (TGFß2), vasoactive intestinal polypeptide (VIP) in guinea pig form-deprived myopia. METHODS: Four-week-old pigmented guinea pigs were randomly assigned to 4 groups: normal control, deprivation, deprivation plus DL-α-AAA, deprivation plus saline. Form deprivation was induced with the self-made translucent eye shields, and lasted for 14 days. 8µg DL-α-AAA was injected into the vitreous chamber of deprived eyes. The corneal radius of curvature, refraction and axial length were measured. Retinal dopamine content was evaluated by the high-performance liquid chromatography with electrochemical detection, and TGFß2 and VIP protein were detected by Western blotting. RESULTS: Fourteen days of eye occlusion caused the axial length to elongate and become myopic in the form-deprived eyes, with the decrease of retinal dopamine and the increase of TGFß2 and vasoactive intestinal polypeptide (VIP) protein. Intravitreal injection of DL-α-AAA could inhibit the myopic shift from (-3.65±1.06)D to (-1.48±0.63)D, P<0.01 due to goggles occluding and cause the decrease of retinal TGFß2 protein in the deprived eyes. However, intravitreal injection of DL-α-AAA had no significant effect on retinal dopamine and VIP protein in deprived eyes. Retinal TGFß2 protein correlated highly with the ocular refraction (y=-3.34+0.31/x, F=74.75, P<0.001) and axial length (y=8.39-0.02/x, F=48.32, P<0.001) in different treatment groups. CONCLUSION: Intravitreal injection of DL-α-AAA is effectively able to suppress the development of form deprivation myopia, which may be associated with retinal TGFß2 protein in guinea pigs.

HIF-1α siRNA reduces retinal neovascularization in a mouse model of retinopathy of prematurity.

OBJECTIVE: To explore the effect of HIF-1α specific siRNA expression vector pSUPERH1-siHIF-1α on retinal neovascularization in a mouse model of retinopathy of prematurity (ROP). METHODS: Forty-eight newborn C57BL/6J mice were randomly divided into the control and experimental groups (n=24 apiece) to create the model of ROP following the methods described by Smith et al. Twelve days after birth, the experimental group received intravitreal injection with pSUPERH1-siHIF-1α; meanwhile, mice in the control group were injected with empty vectors. The expressions of HIF-1α and vascular endothelia growth factor (VEGF) in the retina were examined by Western blotting in both groups. The differences in the neovascular endothelial cell count were compared based on the FITC-Dextran fluorescence stretched preparation/sections. RESULTS: Compared with the control group, the expressions of HIF-1α and VEGF significantly decreased in the experimental group (P<0.01). Meanwhile, the number of retinal neovascular endothelial nuclei that had protruded the internal limiting membrane was significantly lower in the experimental group than in control group (P<0.01). CONCLUSIONS: RNA interference targeting HIF-1α can effectively inhibit the retinal neovascularization of ROP.

Activation of the ERK 1/2 and STAT3 signaling pathways is required for 661W cell survival following oxidant injury.

AIM: To evaluate the influence of hydrogen peroxide (H(2)O(2)) on mouse photoreceptor-derived 661W cell survival and to determine the effect of PD98059, an inhibitor for MEK1 (the direct upstream activator of ERK1/2), and S3I201, a STAT3- specific inhibitor on 661W cell survival after H(2)O(2) exposure. METHODS: The mouse photoreceptor-derived 661W cells were cultured. 661W cells were treated for 12 hours with different concentrations (0, 0.25, 0.50, 0.75, 1mmol/L) of H(2)O(2) and cell viability was determined by 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide ) (MTT) assay. 661W cells were treated with different concentrations H(2)O(2) (0, 5, 10, 50, 500, 1000 µmol/L) for 15 minutes or 1mmol/L H(2)O(2) for different time points (0,5,10,15,30 minutes), and p-Tyr705-STAT3, STAT3, Phospho-p44/42 MAPK (Thr202/Tyr204), ERK1/2 were surveyed by immunoblot analysis. After treatment with 50µmol/L PD98059, or S3I201 for 1 hour, the inhibition efficiency of cell signal pathways was analyzed by immunoblot analysis and the effects of inhibitors on cell viability were determined by MTT. RESULTS: After treating with different concentrations of H(2)O(2) for 12 hours, the cell viability of 661W cells decreased in concentration-dependent manner (P<0.05). Moreover, H(2)O(2) induced phosphorylation of ERK1/2 and STAT3 in 661W cells (P<0.05). After pretreatment with 50µmol/L PD98059 or S3I201 for 1 hour, H(2)O(2)-induced phosphorylation of ERK1/2 or STAT3 was suppressed separately (P<0.05). Using PD98059 or S3I201 to inhibit ERK1/2 or STAT3 signal pathway, the cell viability of 661W cells decreased significantly (P<0.05). CONCLUSION: We demonstrated that the exposure of 661W cells to H(2)O(2) increased the activation of ERK1/2 and STAT3 signal pathways. Activation of these pathways is required for 661W cell survival following oxidant injury.

Retinoic acid metabolic change in retina and choroid of the guinea pig with lens-induced myopia.

AIM: To investigate the role of retinoic acid (RA) and retinaldehyde dehydrogenase-2 (RALDH(2)) of retina and choroid in the guinea pig lens-induced myopic eyes. METHODS: Totally 45 guinea pigs, at age of three weeks, were randomly assigned into three groups: the normal control, the lens-induced group and the recovering group. Out of focus was induced by the -6.00D concave lens on the left eye, and lasted for 15 days. All animals underwent biometric measurement (corneal radius of curvature, refraction and axial length). Subsequently, RA content in the retina and RPE/choriod complex was detected by reversed-phase high-performance liquid chromatography. RALDH(2) protein in the retina and RPE/choriod complex was evaluated by the immunohistochemical staining and Western blotting. RESULTS: After wearing -6.00D lens for 15 days, axial length of the lens-induced eye extends and myopia was formed, with RA contents increasing in both the neural retina and RPE/choroid complex. Comparing with the lens-induced group, myopic degree significantly relieved, and its RA contents in both the neural retina and RPE/choroid complex decreased in the recovering group. In the normal control, RALDH(2) protein was expressed positively in the retinal nerve fiber layer (RNFL), inner plexiform layer (IPL) and lateral border of outer nuclear layer (ONL). Retinal RALDH(2) protein increased in the lens-induced group, and was also positive in the outer plexiform layer (OPL). In the recovering group, retinal RALDH(2) protein attenuated the expression in the OPL turns to negative. RALDH(2) protein was not expressed in the choroid of any group. CONCLUSION: RA of retina and chorid participates in the regulation of the lens-induced myopia in guinea pigs, which may be related with retinal RALDH(2) protein.

[HIF-1α siRNA reduces retinal neovascularization in a mouse model of retinopathy of prematurity].

OBJECTIVE: To study the inhibition effect of HIF-1α specific siRNA expression vector pSUPERH1-siHIF-1α on retinal neovascularization in a mouse model of retinopathy of prematurity (ROP). METHODS: The mouse model of ROP was prepared by the method Smith described. Forty-eight ROP mice were randomly divided into two groups: an experimental group that was intravitreously injected with pSUPERH1-siHIF-1α and a control group that was injected with pSUPER retro vector. The levels of HIF-1α and vascular endothelia growth factor (VEGF) in the retina were examined by Western blot. The retinal neovascularization was evaluated by angiography using FITC Dextran and quantitated histologically. RESULTS: The levels of HIF-1α and VEGF in the retina in the experimental group were reduced 90% and 65% respectively compared with those in the control group. Meanwhile, the number of retinal neovascular endothelial nucleus outbreaking the inner limit membrane in the experimental group was significantly reduced compared with that in the control group. CONCLUSIONS: The development of retinal neovascularization of ROP can be markedly inhibited by RNA interference targeting HIF-1α.

Modulation of TGFß(2) and dopamine by PKC in retinal Müller cells of guinea pig myopic eye.

AIM: To investigate the effect of protein kinase C (PKC) on transforming growth factor-ß(2) (TGFß(2)) and dopamine in retinal Müller cells of guinea pig myopic eye. METHODS: Myopia was induced by translucent goggles in guinea pig, whose retinal Müller cells were cultured using the enzyme-digesting method. Retinal Müller cells were divided into 5 groups: normal control, myopia, myopia plus GF109203X, myopia plus PMA, myopia plus DMSO. PKC activities were detected by the non-radioactive methods. TGFß(2) and tyrosine hydroxylase (TH) proteins were analyzed by Western Blotting in retinal Müller cells. Dopamine was determined by the high-performance liquid chromatography-electrochemical detection in suspensions. RESULTS: After 14 days deprived, the occluded eyes became myopic with ocular axle elongating. Müller cells of guinea pigs were obtained using enzyme digestion. Compared with normal control group, the increase in PKC activity and the up-regulation in TGFß(2) expression were found in retinal Müller cells of myopic eyes, with the decrease of TH and dopamine content (P<0.05). After PKC activated by PMA, TGFß(2) and TH content were up-regulated with the increase of dopamine content (P<0.05). While the PKC activities was inhibited by GF109203X, proteins of TGFß(2) and TH were down-regulated in the myopic eyes, with the decrease of dopamine content (P<0.05). CONCLUSION: TGFß(2) and dopamine are modulated by PKC in Müller cells of the myopic eyes in guinea pig.

The correlation between the regulation of recombinant human IGF-2 on eye growth and form-deprivation in guinea pig.

OBJECTIVE: By investigating the effects of recombinant human IGF-2 (rhIGF-2) on the diopter, axial eye length and the expression of IGF-2 in non-form-deprivation (FD) and FD eyes of guinea pig, we tried to elucidate the relationship between the effects of rhIGF-2 on eye growth and FD in guinea pig. METHODS: Eighty 3-week-old guinea pigs were included in the study, which were divided into two groups randomly. Group A (n = 40) was the non-FD group, Thirty-two guinea pigs received intravitreal injections of either 1 ng, 10 ng, 100 ng rhIGF-2 or bovine serum albumin (BSA) to the right eye; eight guinea pigs who received no intravitreal injections served as control. Group B (n = 40) was the FD group; the right eyes were form-deprived, and received the same disposals as group A. The diopter and the axial eye length of all guinea pigs were measured at day 14. The expression of IGF-2 in the retina was measured by Western blot. RESULTS: After 14 days, FD eyes were high myopia. The axial length of FD eyes was significant for longer than that of non-FD eyes. The expression of IGF-2 in the retina of FD eyes was up-regulated. In non-FD group, there was no significant difference in the diopter and axial eye length among rhIGF-2 injection eyes, BSA injection eyes and control eyes, but the expression of IGF-2 in the retina of 10 ng and 100 ng rhIGF-2 injection eyes was obviously down-regulated. In the FDM (form-deprivation myopia) group, the myopic diopter and axial eye length increased in 10 ng and 100 ng rhIGF-2 injection eyes compared with those in BSA injection eyes and control eyes. The level of IGF-2 expression in the retina of 10 ng and 100 ng rhIGF-2 injection eyes was obviously down-regulated. The diopter and expression of IGF-2 in the retina of rhIGF-2 injection eyes was negatively correlated with the dose of each injection, which was positively correlated with the axial length. CONCLUSION: RhIGF-2 intravitreous injection does not affect the diopter and axial length in non-FD eyes of guinea pig, while it can induce a significant increase in myopic diopter and axial length of FD eyes. RhIGF-2 can promote the development of FDM on the condition of FD.

TGF-beta2 in human retinal pigment epithelial cells: expression and secretion regulated by cholinergic signals in vitro.

PURPOSE: To investigate the (i) effect(s) of cholinergics on the expression and secretion of transforming growth factor (TGF)-beta(2) in human retinal pigment epithelium (RPE) and (ii) mechanism of action of atropine in the treatment of myopia. MATERIALS AND METHODS: The RPE cell line, D407, was (i) treated with carbachol (10 microM), (ii) treated with atropine (10 nM-100 microM), or (iii) pre-treated with atropine (10 nM-100 microM) and then exposed to carbachol (10 microM). A no-treatment group served as control. Expression of TGF-beta(2), after stimulation at different time points (2, 4, 8, 16, 24, and 48 hr), was measured by RT-PCR and Western blot analysis. Secretion of TGF-beta(2) was determined by ELISA. RESULTS: Carbachol induced a time-dependent increase in the levels of TGF-beta(2) mRNA and protein in the cytoplasm (p < 0.001). ELISA assays showed a time-dependent increase in levels of TGF-beta(2) protein in the supernatant with carbachol treatment (p < 0.001). There was no change of TGF-beta(2) in the cytoplasm or supernatant with atropine alone (p > 0.05). The increased expression and secretion of TGF-beta(2) caused by carbachol were suppressed by atropine (in the range of 10 nM-100 microM) when compared to treatment with carbachol alone (p < 0.001). The stimulating effect of 10 microM carbachol was inhibited completely by 100 microM atropine. CONCLUSIONS: In RPE cells, atropine inhibits the expression and secretion of TGF-beta(2) by blocking the muscarinic acetylcholine receptor (mAChR), which may control the development of myopia.

[Inhibitory effects of HSV-tk/GCV system mediated by recombinant adeno-associated virus 2 on rabbit lens epithelial cells].

OBJECTIVE: To study the inhibitory effects of recombinant adeno-associated virus 2 (rAAV2)-mediated herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) system on the rabbit lens epithelial cells (N/N1003A) in vitro and to investigate the mechanism of cell death. METHODS: After N/N1003A cells had been transfected with rAAV2-EGFP, expression of enhanced green fluorescent protein (EGFP) were observed by inverted fluorescent microscope and the transfection efficiency was detected by flow cytometry. N/N1003A cells were infected by recombinant virus rAAV2/HSV-tk as the treated group, and the uninfected N/N1003A cells were used as the controls. The dose- and time-dependent efficiency and bystander effect of HSV-tk/GCV system on the cells were studied by MTT assay. Apoptosis and necrosis were observed by phase contrast microscope, electron microscope and Hoechst33258 stain. Apoptotic cell rate and cell cycle were detected by flow cytometry. RESULTS: rAAV2 vector encoding EGFP gene could be transfected into N/N1003A cells stably and efficiently. The effects of GCV on these two groups were dose-dependent (F = 13.076. 239, P < 0.001). The difference of percentages of survival cells between the study group and the control group at various doses of GCV was statistically significant (F = 53,47.119, P < 0.001). The 50% of the inhibitory concentration (IC50) of GCV in the study group was 2 mg/L and was 524 mg/L in the control group. The killing efficiency of GCV increased with the prolongation of time and showed significant bystander effect. Cell apoptosis and necrosis were observed in N/N1003A-tk cells transfected by GCV, and the percentage of apoptotic cells was significantly higher than that of the control group (t = 3.83, P < 0.01). The percentages of N/N1003A-tk cells in the S phase of the cell cycle was significantly higher than that of the control group (t = 3.55, P < 0.01). Whereas the percentages of the G0/ G1 phase in GCV treated cells was significantly lower than that of the control group ( t = 4.29, P < 0.01). CONCLUSIONS: GCV can kill efficiently the N/N1003A cells infected by recombinant virus rAAV2/HSV-tk, and there is strong bystander effect. Recombinant adeno-associated virus-mediated HSV-tk/GCV suicide gene system may provide an effective approach for the treatment of lens posterior capsular opacification.

[Effect of vasoactive intestinal peptide receptor antagonist VIPhybrid on the development of form deprivation myopia in chicks].

OBJECTIVE: To investigate the effect of regulation of VIPhybrid, an unselective antagonist of vasoactive intestinal peptide receptors (VIPR), on the formation and development of form deprivation myopia (FDM) in chick and the expression of protein and mRNA of VIP on the retina and choroids of in chicks. METHODS: Seventy-two 1-day-old yellow healthy leghorn chicks were assigned into 6 groups (12 in each group). Eyes in Group I were covered on the right as a blank control group. Eyes in GroupII were those eyes having been injected with 20 microL saline into vitreous cavity and then covered as a negative control group. Eyes in GroupIII,IV and V were injected with 20 microL VIPhybrid with low (3*10(-12) mol/L), middle (3*10(-10) mol/L) and high (3*10(-8) mol/L) dosage into vitreous cavity and then covered as experimental groups. The above groups had been continuously covered for 1 week. Eyes in Group VI were uncovered and uninjected as a normal control group. Diopter was detected using retinoscopic refraction. The eyeball axis was determined using ophthalmological ultra-A. The expression of protein and mRNA of VIP on retina-choroids-sclera were investigated by SP immunohistochemistry staining and RT-PCR. RESULTS: Form deprivation for 1 week induced high myopia eyes and elongated eyeball axis in GroupI and GroupII, and there was no difference between the 2 groups (P>0.05). The diopter and eyeball axis were significantly reduced in Group III, IV, and V as compared with Group I and II (P<0.01), but the diopter was higher and the eyeball axis was longer than those of Group VI. The diopter and eyeball axis had negative correlation with the concentration gradient of VIPhybrid. The expressions of protein and mRNA of VIP in Group III, IV, and V were down-regulated as compared with those of Group I and I I(P<0.01)and also down-regulated with the increase of concentration of VIPhybrid. CONCLUSION: VIPhybrid can decrease the development of FDM in chicks, which may provide a new pathway for drug therapy of myopia in human beings.

[Construction and expression of recombinant adeno-associated virus vector containing HSV1-TK gene].

OBJECTIVE: To construct the recombinant adeno-associated virus(rAAV) vector plasmid pSNAV2.0-TK containing HSV1-TK gene, to produce recombinant adeno-associated virus rAAV2/HSV1-TK, and to detect the integration and expression of HSV1-TK gene in lens epithelial cells transfected by rAAV2/HSV1-TK, and to provide foundation for gene therapy of posterior capsular opacification. METHODS: The recombinant vector plasmid constructed by gene recombinant technology was analyzed by PCR and restriction enzyme digestion. The cell strain BHK-21/TK was screened by G418 after the plasmid was transfected into BHK-21 cells,with the helper virus HSV1-rc/UL2 to produce the recombinant virus rAAV2/HSV1-TK. The purity of rAAV2/HSV1-TK was detected by SDS-PAGE and HPLC, and the titre of rAAV2/HSV1-TK was observed by dot blot hybridization. The HSV1-TK gene in lens epithelial cells transfected by rAAV2/HSV-TK was investigated by PCR and RT-PCR. RESULTS: The recombinant plasmid proved successful by PCR and restriction enzyme digestion. The recombinant virus rAAV2/HSV1-TK was produced successfully and its titre was 1 x 10(12) v.g./mL by dot blot hybridization. The HSV1-TK gene was integrated and expressed in lens epithelial cells. CONCLUSION: The recombinant adeno-associated virus vector plasmid containing HSV1-TK gene is successfully constructed, and high titre recombinant adeno-associated virus (rAAV2/HSV1-TK) is obtained. The HSV1-TK gene in lens epithelial cells is expressed after being transfected by rAAV2/HSV1-TK.

[High myopia and retinal ultrastructure of albino guinea-pigs].

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.

[Antisense c-fos oligonucleotides-induced myopia in guinea pigs].

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 (P<0.01). The refraction and axial length were of no statistically significant differences among the sense c-fos oligonucleotides-treated eyes and saline-treated eyes and non-treated eyes (P>0.05). 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.

[Analysis of the dynamic changes of cornea after myopic excimer laser in situ keratomileusis using an Orbscan II topography system].

OBJECTIVE: To study the changes and influence factors of an Orbscan II topography system in myopia after excimer laser in situ keratomileusis (LASIK). METHODS: Two hundred and sixteen myopia patients (230 eyes) were treated by LASIK, their corneal thickness and curve of corneal posterior surface was measured with an Orbscan II topography system before and after surgery. The results of measurement in different time points were compared. RESULTS: The thinnest point of cornea, the mean keratometry of the posterior best fit surface (BFS) and the distance from the apex to the BFS were significant difference before and after operation (P < 0.05). There were significant difference among those groups in different degree of myopia in the same time point (P < 0.05) after surgery, but there were no significant difference in the same group in difference time (P > 0.05). A significant difference in the area of the thinnest cornea before surgery and after surgery was detected among those groups (P < 0.01). The regression equation for preoperative Diff value was established as Y = 0.0941 - 0.000,53X(1) - 0.000,471X(2) - 0.0063X(3) + 0.001,22X(4) (P < 0.01), X(1) = corneal thickness of the thinnest point (microm), X(2) = central corneal thickness (microm), X(3) = corneal diameter (mm), X(4) = length of ocular axis (mm). The regression equation for postoperative decrease Diff value between the third month and the first month was produced as Y = - 0.027 - 0.000,78X(1) + 0.002,01X(2) - 0.0055X(3) (P < 0.01). X(1) = decrease in corneal thickness of the thinnest point (microm), X(2) = intraocular pressure pre-surgery (mmHg), X(3) = decrease in curvature of posterior corneal surface (D). CONCLUSIONS: The application of Orbscan II has an important clinical significance before and after LASIK. The Diff value measured before LASIK for myopia is influenced by the corneal thickness, corneal diameter and ocular axis. The postoperative decrease in Diff value between the third and first month is influenced by the postoperative decrease of corneal thinnest point and curvature of posterior corneal surface, and preoperative intraocular pressure.

[Apoptosis and c-myc protein expression in the retinal of form-deprivation myopia].

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.

[Clinical effects of the mixture of 5-fluorouracil and triamcinolone acetonide on capillary hemangioma of eyelid].

OBJECTIVE: To evaluate the clinical effects of the mixture of 5-fluorouracil (5-FU) and triamcinolone acetonide on capillary hemangioma of eyelid. METHODS: One hundred and one patients with capillary hemangioma of eyelid were divided into Group A and Group B: Group A was injected with triamcinolone acetonide, and Group B was injected the mixture of 5-FU and triamcinolone acetonide. RESULTS: The cure rate was 68.3%, the total effective rate was 76.0%, and the average course of treatment was (8.1+/-3.4) months for Group A; the cure rate was 90.0%, the total effective rate was 96.6%, and the average course of treatment was (5.1+/-2.3) months for Group B. The therapeutic effect in Group B was better than that in Group A (P<0.05). The treatment period in Group B was shorter than that in Group A (P<0.05). CONCLUSION: 5-FU combining with triamcinolone acetonide has not only a better therapeutic effect, but also a shorter period of treatment.

[Multiple factor analysis of visual function in hypermetropic children].

OBJECTIVE: To investigate the characteristics of hypermetropic children whose visual acuity (VA) is declined or accompanied by esotropia. METHODS: One hundred and ninety children were given optometry, strabismus degree and binocular vision measurement. RESULTS: Declined VA appeared in 170 children, while esotropia occurred in 173. Sixty-one got binocular single vision, 17 had fusion function, and 11 had stereoaculty. Spherical equivalent had a linear relationship with VA (P < 0.01), but not with the strabismus degree (P > 0.05). The influence factors of binocular vision were age of discovery, VA and the strabismus degree, while the stereoaculty was influenced by the strabismus degree, spherical equivalent and VA. CONCLUSION: Low VA and strabismus are the most common complaint in children. Ametropia and strabismus do great harm to juvenile binocular vision, and stereoaculty is damaged seriously. We suggest an early examination of visual function in children.

[Dynamic expression of VIPR2 in form deprivation myopia].

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].

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.

[The treatment of retinal apoptosis by Caspase 3 inhibitor Ac-DEVD-CHO in experimental myopia].

OBJECTIVE: To investigate the mechanism of retinal apoptosis in chick experimental myopia and the therapy of Caspase 3 inhibitor Ac-DEVD-CHO. METHODS: Chick myopia was induced by lid-suture. After Ac-DEVD-CHO had been injected into vitreous, myopia was confirmed by optometry. Subsequently, chick eyeballs removed were measured its extro-dimensions, and the change of fundus were observed. Retinal apoptotic cells were determined by electron microscopy, TUNEL technique and flow cytometry. Retinal Caspase 3 proteins and its activities were measured by immunohistochemistry, flow cytometry and a colorimetric method using Ac-DEVD-pNA as a substrate. RESULTS: Ocular diopters and extro-diameters in all sutured eyes remarkly increased in comparison with its control eyes at 12 weeks after lid-suture. Lacquer crack lesions were found in 41 of 90 sutured eyes (45.56%). Apoptotic cells were observed in retinal outer and inner nuclear layer of the sutured eyes, and its apoptotic rate was significantly more than in control eyes (P < 0.05). Moreover, the expression of retinal Caspase 3 proteins and its activities were increased. After Ac-DEVD-CHO was injected into vitreous, the decrease of retinal apoptotic rate, Caspase 3 proteins and its activities was found. The treated effect of Ac-DEVD-CHO was in a dose dependent manner. CONCLUSIONS: Caspase 3 plays an important role in retinal apoptosis of chick myopia. Ac-DEVD-CHO can effectively ameliorate retinal apoptosis by blocked the effect of Caspase 3.