Comparison of 0.02% atropine eye drops, peripheral myopia defocus design spectacle lenses, and orthokeratology for myopia control.

CLINICAL RELEVANCE: There are many methods to control the progression of myopia. However, it is currently unknown which method could better control myopia progression: 0.02% atropine eye drops, peripheral myopic defocus design spectacle lenses (PMDSL), or orthokeratology (OK). BACKGROUND: To compare the efficacy of 0.02% atropine, PMDSL, and OK to control axial length (AL) elongation in children with myopia. METHODS: This study was analysed based on a previous cohort study (0.02% atropine group) and retrospective data (PMDSL and OK group). Overall, 387 children aged 6-14 years with myopia - 1.00D to - 6.00D in the three groups were divided into four subgroups according to age and spherical equivalent refraction (SER). The primary outcome was changed in AL over 1-year. RESULTS: The mean axial elongation was 0.30 ± 0.21 mm, 0.23 ± 0.16 mm, and 0.17 ± 0.19 mm in the 0.02% atropine, PMDSL, and OK groups, respectively. Multivariate linear regression analyses showed significant differences in axial elongation among the three groups, especially in children aged 6-10, but not in children aged 10.1-14; the corresponding axial elongation was 0.35 ± 0.21 mm, 0.23 ± 0.17 mm, and 0.21 ± 0.20 mm (P < 0.05 between any two groups, except between PMDSL and OK groups at P > 0.05) and 0.22 ± 0.20 mm, 0.21 ± 0.13 mm, and 0.13 ± 0.18 mm (P < 0.05 between any two groups, except between 0.02% atropine and PMDSL groups at P > 0.05) in children with SER from - 1.00D to - 3.00D and from - 3.01D to - 6.00D, respectively. CONCLUSIONS: Within the limits of this study design and using only the current brand of PMDSL, OK appeared to be the best method, followed by PMDSL and then 0.02% atropine, for controlling AL elongation over one year. However, different effects were found in the various age and SER subgroups.

Effect of 0.02% and 0.01% atropine on ocular biometrics: A two-year clinical trial.

Background: Several studies have shown that various concentrations of low-concentration atropine can reduce myopia progression and control axial elongation safely and efficiently in children. The aim of this study was to evaluate the effects of 0.02% and 0.01% atropine on ocular biometrics. Methods: Cohort study. 138 and 142 children were randomized to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine applied to both eyes nightly. Controls (N = 120) wore only SV spectacles. Ocular and corneal astigmatism were calculated using Thibos vector analysis and split into J0 and J45. Results: The changes in cycloplegic spherical equivalent refraction (SER) and axial length (AL) were -0.81 ± 0.52D, -0.94 ± 0.59D, and -1.33 ± 0.72D; and 0.62 ± 0.29 mm, 0.72 ± 0.31 mm, and 0.89 ± 0.35 mm in the 0.02% and 0.01% atropine and control groups, respectively (all P < 0.05). Both anterior chamber depth (ACD) and ocular astigmatism (including J0) increased, and lens power decreased in the three groups (all P < 0.05). However, there were no differences in the changes in ACD, ocular astigmatism, and lens power among the three groups (all P > 0.05). Intraocular pressure (IOP), corneal curvature, ocular astigmatism J45, and corneal astigmatism (including J0 and J45) remained stable over time in the three groups (all P > 0.05). The contributions to SER progression from the changes in AL, lens and corneal power of the three groups were similar (P > 0.05). The contribution of AL change alone to the change in SER was 56.3%, 63.4% and 78.2% in the above corresponding three groups. Conclusions: After 2 years, 0.02% and 0.01% atropine had no clinical effects on corneal and lens power, ocular and corneal astigmatism, ACD or IOP compared to the control group. 0.02% and 0.01% atropine helped to control myopia progression mainly by reducing AL elongation.

Macular hole following phakic intraocular lens implantation: A case report.

BACKGROUND: Phakic intraocular lens (pIOL) implantation has been commonly prescribed and is considered as a safe and effective option for correcting high myopia. However, it is associated with multiple complications. CASE SUMMARY: This report describes a case of full-thickness macular hole (MH) in a patient with a history of bilateral pIOL implantation for the correction of myopia of -12.00 diopters in both eyes 7 mo ago. The MH closed after pars plana vitrectomy with internal limiting membrane removal and the best-corrected visual acuity improved to 20/40 in the left eye. CONCLUSION: In rare cases, MH can occur following pIOL. In this present case report, we analyzed the formation process of MH following the surgery and emphasized that it is important to inform highly myopic patients about the risk of MH occurrence while being aware of the symptoms of this complication.

Effect of 0.02% and 0.01% atropine on astigmatism: a two-year clinical trial.

BACKGROUND: To evaluate the effects of 0.02% and 0.01% atropine eye drops on ocular and corneal astigmatism over 2 years. METHODS: A prospective clinic-controlled trail. The cohort study assessed 400 myopic children and divided them into three groups: 138 and 142 children were randomized to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine applied to both eyes once nightly. Control children (n = 120) only wore SV spectacles. Spherical equivalent refractive errors (SER) and corneal curvature were measured every 4 months. The SER and corneal curvature were assessed by cycloplegic autorefraction and IOLMaster. Ocular and corneal astigmatism were calculated by Thibos vector analysis and then split into its power vector components, J0 (with-the-rule astigmatism) and J45 (oblique). RESULTS: After 2 years, the ocular astigmatism increased by -0.38 ± 0.29 D, -0.47 ± 0.38 D, -0.41 ± 0.35 D in the 0.02%, 0.01% atropine groups and control group, respectively (p = 0.15). The corresponding corneal astigmatism increased by -0.20 ± 0.34 D, -0.28 ± 0.35 D and -0.26 ± 0.26 D (p = 0.18). The ocular astigmatism J0 increased by 0.19 ± 0.28 D, 0.22 ± 0.36 D, 0.18 ± 0.31 D in the 0.02% atropine, 0.01% atropine and control groups, respectively (p = 0.65). The corresponding corneal astigmatism J0 increased by -0.05 ± 0.34 D, -0.11 ± 0.37 D and -0.13 ± 0.30 D (p = 0.23). There was a small but significant increase in ocular astigmatism (including J0) (all P < 0.05), but there were no changes in the ocular astigmatism J45 and corneal astigmatism (including J0 and J45) in the three groups over time (all p > 0.05). However, there were no significant differences in the changes in ocular astigmatism (including J0) among the three groups. CONCLUSIONS: Treatment with 0.02% and 0.01% atropine had no clinically significant effect on ocular and corneal astigmatism over 2 years. TRIAL REGISTRATION: The First Affiliated Hospital of Zhengzhou University, ChiCTR-IPD-16008844 . Registered 14/07/2016.

Complement factor B knockdown by short hairpin RNA inhibits laser-induced choroidal neovascularization in rats.

AIM: To evaluate whether recombinant complement factor B (CFB) short hairpin RNA (shRNA) reduces laser-induced choroidal neovascularization (CNV) in rats. METHODS: Laser-induced rat CNV model was established, and then the animals underwent fundus fluorescence angiography (FFA) and hematoxylin and eosin (HE) staining. On day 3 and 7 after photocoagulation, the expression of CFB and membrane attack complex (MAC) was detected by immunhischemistry. A recombinant CFB-shRNA plasmid was constructed. CFB and scrambled shRNA plasmids were intravenous injected into rats via the tail vein on the day of laser treatment, respectively. On day 7, the incidence of CNV was determined by FFA, and the expression of CFB and vascular endothelial growth factor (VEGF) in retinal pigment epithelium (RPE)/choroidal tissues was detected by immunhischemistry, Western blot and/or semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) in CFB and scrambled shRNA groups. The possible adverse effects of CFB-shRNA injection were assessed by transmission electron microscopy and electroretinography. RESULTS: FFA and HE results indicated that a laser-induced rat CNV model was successfully established on day 7 after photocoagulation. The expression of CFB and MAC was extremely weak in normal retina and choroid, and increased on day 3 after photocoagulation. However, it started to reduce on day 7. CFB shRNA plasmid was successfully constructed and induced CFB knockdown in the retinal and choroidal tissues. FFA showed CFB knockdown significantly inhibited incidence of CNV in rats. Moreover, CFB knockdown significantly inhibited the expression of VEGF in RPE/choroidal tissues. CFB shRNA caused no obvious side effects in eyes. CONCLUSION: CFB knockdown significantly inhibits the formation and development of CNV in vivo through reducing the expression of VEGF, which is a potential therapy target. The alternative pathway of complement activation plays an important role in CNV formation.

Influence of air quality on the selection tendency of contact lens wearers.

OBJECTIVE: This study aimed to investigate whether air quality influences ocular comfort when wearing contact lenses and the selection tendency of myopic populations who wears contact lenses. METHODS: Questionnaires were distributed to one hundred and twenty corneal contact lens wearers to understand whether the respondents would reduce or stop the use of contact lenses according to air quality and to evaluate and compare their ocular status under different air quality conditions. RESULTS: Forty-three point eight percent of the respondents were concerned about reduced oxygen permeability of contact lenses and increased contact lens-associated complications caused by the adsorption and accumulation of haze particles on the contact lens. Thirteen point four percent of the respondents stated that they would stop using contact lenses during moderate to severe air pollution and switch to glasses. Twenty-eight point six percent of respondents remarked that they would reduce the use of contact lenses depending on the situation during moderate to severe air pollution. However, this study did not find statistically significant differences in the ocular comfort while wearing contact lenses and in the eye scores of contact lens wearers under different air quality conditions. CONCLUSION: Air quality has an impact on the selection tendency of some contact lens wearers. However, whether moderate or more severe air pollution causes ocular discomfort or contact lens-associated complications in contact lens wearers awaits further investigation.

Will the long-term use of atropine eye drops in children increase the risk of dry eye?

In recent years, some studies indicates that atropine eye drops is one of the most effective interventions for myopia. Due to large demand, the use of low-concentration atropine eye drops to reduce myopia progression is popular in China. Considering that the underlying mechanism of atropine eye drops in controlling the progression of myopia is still unclear, it is reasonable to pay enough attention to whether the long-term use of atropine eye drops in children will increase the risk of dry eye.

Safety, pharmacokinetics, and prevention effect of intraocular crocetin in proliferative vitreoretinopathy.

The study was designed to determine the safety and pharmacokinetics of intraocular crocetin and examine whether crocetin inhibits the development of proliferative vitreoretinopathy (PVR) in a rabbit model. In the toxicity study, the right eyes of rabbits were injected with 0.2 µmol or 0.4 µmol crocetin. The left eyes were injected with 0.1 ml phosphate buffered saline (PBS) containing the same concentration of DMSO. Fundus photography, optical coherence tomography (OCT), and electroretinogram (ERG) were obtained at baseline and 14 days. Afterward, the eyes were enucleated for histopathological analysis and terminal deoxynucleotidyl transferasemediated dUTP nick end labeling (TUNEL) assay. In the pharmacokinetic study, the eyes received an intravitreous injection of 0.4 µmol crocetin to detect vitreous drug levels with HPLC at specific time points. In the efficacy study, PVR was induced with an intravitreal injection of ARPE-19 cells in rabbits. Then ten eyes were injected with 0.4 µmol crocetin, and the other 10 eyes received 0.1 ml PBS. Fundus photography, OCT and ERG were performed at days 3 and 7 and weekly for a total of 4 weeks after injection. Afterward, the eyes were enucleated and subjected to histological analysis and TUNEL staining. The results demonstrated no signs of retinal toxicity. Intravitreal injection of 0.4 µmol crocetin had a half-life of 4.231 h. Treatment with crocetin significantly inhibited the progression of PVR in parallel with a reduced expression of α-SMA, collagen fibers and Ki67. These results indicate that crocetin is an effective and safe inhibitor of PVR in rabbit models.

Effects of Curcumin on Epidermal Growth Factor in Proliferative Vitreoretinopathy.

BACKGROUND/AIMS: Proliferative vitreoretinopathy (PVR) is a common refractory eye disease that causes blindness and occurs after retinal detachment or retinal reattachment. Epidermal growth factor (EGF) has been shown to play an important role in the migration and proliferation of retinal pigment epithelium (RPE) cells, which promote PVR. Curcumin inhibits RPE cell proliferation, but it is not known whether it participates in the formation of PVR. Curcumin regulates the biological functions of EGF, which plays important roles in the development of PVR. This study aimed to evaluate the effect of curcumin on the regulation of EGF in PVR. METHODS: Rabbit RPE cells were cultured, and EGF expression was detected by immunocytochemistry. MTT assay was conducted to determine cell proliferation induced by different concentrations of EGF. Immunocytochemical staining was used to detect EGF expression after treatment with curcumin at varying concentrations. Real-time PCR (RT-PCR) and western blot analysis were used to detect the concentrations of EGF mRNA and protein after treatment with curcumin. After RPE cells and curcumin were injected into experimental rabbit eyes, the cornea, aqueous humor, lens, and vitreous opacity were observed and recorded simultaneously by indirect ophthalmoscopy, fundus color photography, and B-ultrasonography. The vitreous body was extracted, and the EGF content in the vitreous humor was measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: At each time point (24, 48, and 72 h), cell proliferation gradually increased with increasing EGF concentrations (0, 3, 6, and 9 ng/mL) in a dose-dependent manner. Cell proliferation between EGF concentrations of 9 and 12 ng/mL were no different, which suggested that 9 ng/mL EGF was the best concentration to use to stimulate RPE cell proliferation in vitro. Under all EGF concentrations (0, 3, 6, 9, and 12 ng/mL), RPE cell proliferation increased with time (from 24 to 72 h), suggesting a time-effect relationship. Curcumin downregulated EGF expression in RPE cells, which also indicated time-effect and dose-effect relationships. The best curcumin concentration for the inhibition of EGF expression was 15 µg/mL. RT-PCR and western blot analyses indicated that the EGF mRNA and expression of the protein in RPE cells treated with curcumin significantly decreased with time. Ocular examinations revealed that the vitreous opacity was lower and the proliferative membrane was thinner in the curcumin group compared with the control group. The PVR grade and the incidence of retinal detachment were significantly lower in the experimental group than in the control group. ELISA results showed that the EGF content in vitreous humor was higher in the control group than in the curcumin group. The curcumin and control groups were significantly different at each time point. CONCLUSION: Curcumin inhibited RPE cell proliferation by downregulating EGF and thus effectively inhibited the initiation and development of PVR.

Effects of apelin on retinal microglial cells in a rat model of oxygen-induced retinopathy of prematurity.

This study explores the effects of apelin on retinal microglial cells in rat models of oxygen-induced retinopathy of prematurity (ROP). Totally, 274 rats were selected for establishing oxygen-induced retinopathy (OIR) models, and 92 healthy rats for control group. OIR rats were assigned into OIR, 10-5 g/L apelin, 10-4 g/L apelin, and 10-3 g/L apelin groups. Immunohistochemistry was employed to determine morphology of microglial cells and cell number. CDllb, ionized calcium-binding adapter molecule 1 (IBA-1), TNF-α, and iNOS mRNA and protein expressions were identified using RT-qPCR and Western blotting, respectively. ELISA was employed to determine the levels of VEGF and glial fibrillary acidic protein (GFAP). The amoeboid microglial cells were found in the OIR and 10-3 g/L apelin groups, while bipolar microglial cells were found in the normal control, 10-5 g/L apelin and 10-4 g/L apelin groups. In the 1, 2, 3, and 4th week after apelin treatment, there were significantly decreased bipolar microglial cells, lower mRNA and protein expressions of CDllb, IBA-1, TNF-α and iNOS, and the levels of VEGF and GFAP in the 10-4 g/L apelin group than in the OIR, 10-3 g/L apelin and 10-5 g/L apelin groups. The differences between the normal control and 10-4 g/L apelin groups are not significant. Compared with the OIR group, the 10-5 g/L apelin and 10-3 g/L apelin groups presented decreased microglial cells and mRNA and protein expressions of CDllb, IBA-1, TNF-α, and iNOS. Appropriate concentration of apelin may reduce retinal microglial cells in a rat model of oxygen-induced ROP.

Crocetin inhibits the proliferation, migration and TGF-ß2-induced epithelial-mesenchymal transition of retinal pigment epithelial cells.

Retinal pigment epithelial (RPE) cells, the major cell type in the fibrotic membrane of proliferative vitreoretinopathy, display enhanced proliferative and migratory capacities and epithelial-mesenchymal transition (EMT). In this study, we investigated the potential impact of crocetin on the proliferation, migration and EMT of cultured ARPE-19 cells. The cells were treated with crocetin alone or in combination with transforming growth factor-ß2 (TGF-ß2). Cell proliferation was examined using the CCK-8 assay. Cell cycle distribution was analyzed by flow cytometry after propidium iodide staining. The expression levels of proliferating cell nuclear antigen (PCNA), p21 and p53 were examined by Western blot analysis. Cell migration was assessed by in vitro scratch and Transwell assays. Real-time PCR, Western blotting and immunofluorescence were used to assess EMT features. Treatment of ARPE-19 cells with crocetin (50-200µM) significantly inhibited their proliferation and migration in a concentration- and time-dependent manner. Crocetin induced G1 arrest, reduced PCNA protein expression and increased the p21 and p53 accumulation in ARPE-19 cells. Crocetin inhibited TGF-ß2-induced EMT in ARPE-19 cells by maintaining the expression of E-cadherin and ZO-1 and by reducing the expression of vimentin and α-SMA through the suppression of phosphorylation of p38. These results indicate that crocetin is an effective inhibitor of the proliferation, migration and TGF-ß2-mediated EMT of ARPE-19 cells.

Risk factors for diabetic retinopathy in northern Chinese patients with type 2 diabetes mellitus.

AIM: To investigate the prevalence and risk factors of diabetic retinopathy (DR) in northern Chinese patients with type 2 diabetes mellitus (T2DM). METHODS: This retrospective cross-sectional study was performed between May 2011 and April 2012. A total of 1100 patients (male/female, 483/617) were included in this study. DR was defined following the Early Treatment Diabetic Retinopathy Study (ETDRS) severity scale. All included patients accepted a comprehensive ophthalmic examination including retinal photographs. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence interval (CI) after adjusting for age and gender. RESULTS: Retinopathy was present in 307 patients with a prevalence of 27.9%. In univariate logistic analysis, presence of DR was associated with longer duration of diabetes (OR, 5.70; 95%CI, 2.91-12.56), higher concentration of fasting blood glucose (OR, 12.94; 95%CI, 2.40-67.71), higher level of glycosylated hemoglobin HbA1c (OR, 5.50; 95%CI, 3.78-11.97) and insulin treatment (OR, 6.99; 95%CI, 1.39-35.12). The lifestyle of patients with T2DM including smoking, alcohol consumption and regular exercise seemed not associated with the development of DR. CONCLUSION: Our study suggests that fasting serum glucose concentration, HbA1c level, duration of diabetes and insulin treatment are potential risk factors for DR in northern Chinese patients with T2DM, while the lifestyle of included patients seems not associated with DR.

Effects of posterior corneal astigmatism on the accuracy of AcrySof toric intraocular lens astigmatism correction.

AIM: To evaluate the effects of posterior corneal surface measurements on the accuracy of total estimated corneal astigmatism. METHODS: Fifty-seven patients with toric intraocular lens (IOL) implantation and posterior corneal astigmatism exceeding 0.5 diopter were enrolled in this retrospective study. The keratometric astigmatism (KA) and total corneal astigmatism (TA) were measured using a Pentacam rotating Scheimpflug camera to assess the outcomes of AcrySof IOL implantation. Toric IOLs were evaluated in 26 eyes using KA measurements and in 31 eyes using TA measurements. Preoperative corneal astigmatism and postoperative refractive astigmatism were recorded for statistical analysis. The cylindrical power of toric IOLs was estimated in all eyes. RESULTS: In all cases, the difference of toric IOL astigmatism magnitude between KA and TA measurements for the estimation of preoperative corneal astigmatism was statistically significant. Of a total of 57 cases, the 50.88% decreased from Tn to Tn-1, and 10.53% decreased from Tn to Tn-2. In all cases, 5.26% increased from Tn to Tn+1. The mean postoperative astigmatism within the TA group was significantly lower than that in the KA group. CONCLUSION: The accuracy of total corneal astigmatism calculations and the efficacy of toric IOL correction can be enhanced by measuring both the anterior and posterior corneal surfaces using a Pentacam rotating Scheimpflug camera.

Altered TGF-ß2 and bFGF expression in scleral desmocytes from an experimentally-induced myopia guinea pig model.

PURPOSE: To determine changes in expression of transforming growth factor ß-2 (TGF-ß2) and basic fibroblast growth factor (bFGF) in scleral desmocytes from anterior and posterior portions of experimentally-induced myopic eyes of guinea pigs. METHODS: Three groups (n = 10) of 2-week-old guinea pigs were used to develop concave lens-induced myopia (LIM) in one eye via the out-of-focus method for 6, 15, or 30 days respectively, while the other eye in each guinea pig served as the self-control (SC). After myopia induction, lenses were removed, and scleral fibroblasts were cultured and passaged twice. TGF-ß2 and bFGF expression levels of scleral desmocytes in LIM and SC groups were compared by immunocytochemistry, quantitative real-time PCR (qRT-PCR) and Western blot analyses. RESULTS: The TGF-ß2 expression of the anterior portion of the sclera in the LIM group was significantly higher at 15 days, and at its highest at 30 days after myopia induction compared with the SC group (P < 0.05). The TGF-ß2 staining of the posterior sclera in the LIM group began to rise significantly at 6 days, peaked at 15 days and remained significantly higher than that of the anterior part, as well as the SC group, even at 30 days after myopia induction (P < 0.05). BFGF levels in scleral desmocytes from the anterior and posterior regions in the LIM group were both significantly lower than those of the SC group at all time points after myopia induction (P < 0.05). Furthermore, as the myopia progressed, bFGF expression in the anterior and posterior sclera in the LIM group gradually and statistically significantly decreased compared with the SC group (P < 0.05); however, no significant differences were observed between the anterior and posterior parts in the LIM group at any time after myopia induction (P > 0.05). All these results were consistent at the mRNA and protein levels. CONCLUSIONS: During myopia development in lens-induced guinea pigs, the increase in TGF-ß2 activity of scleral desmocytes initiated at the posterior pole. Along with the induction time, the TGF-ß2 activity in all scleral desmocytes became elevated. By contrast, the bFGF activity showed a general decline in all scleral desmocytes, rather than mainly in the posterior pole. These results imply that expression of TGF-ß2 in scleral desmocytes plays a direct role, while that of bFGF exerts an indirect role in myopia development.

Retinoic acid suppresses the adhesion and migration of human retinal pigment epithelial cells.

The study was designed to better understand how retinoic acid (RA) influenced the migration and invasion abilities of retinal pigment epithelial cells (RPE) in vitro and how the related genes of the extracellular matrix (ECM) were expressed. The inhibition effects of RA on proliferative vitreoretinopathy (PVR) formation induced by RPE cells were studied in rabbits. Wound healing and Boyden chamber assays were used to show the abilities of migration and invasion of RPE. Microarray, real-time quantitative PCR (qPCR) and Western blotting showed how RA regulated the ECM genes. RA (10(-5) M) significantly (P < 0.05) inhibited PVR membrane and traction retinal detachment formation (80%). Moreover, RA treatment significantly inhibited the migration (80%) and invasion (65%) behaviors of human RPE cells (P < 0.05) by wound healing and Boyden chamber assays, respectively. Microarray and q PCR analysis showed RA treatment did inhibit the motility of human RPE cells by inhibition of metalloproteinases (MMP) 1, 2, 9, fibronectin-1, transforming growth factor beta, thrombospondin-1, tenascin C, most collagen, integrin, laminin molecules and along enhancing E-cadherin and MMP3 genes expression. And Western blotting indicated the coincident results on protein level of MMP1, 2, 3, 9, 14; fibronectin-1; integrinαM, ß2 and E-cadherin. In conclusions, RA is a vital drug to inhibit the abilities of migration and invasion of RPE and to hamper the PVR formation by regulating some genes expression of ECM.

Mechanical behavior of scleral fibroblasts in experimental myopia.

BACKGROUND: The study aims to determine the changes in the biomechanical properties of the anterior and extreme posterior portions of experimental near-sighted eyes by examining the mechanical behavior of guinea pig scleral desmocytes, thus finding a new approach to the pathogenesis of myopia and their corresponding therapies. METHODS: Guinea pigs (2 weeks old) were numbered and assigned into three groups (A, B, and C) with ten guinea pigs each. Concave lens-induced myopic (LIM) animal models were prepared via the out-of-focus method. The other eye in the same guinea pig served as the self-control (SC) group. After modeling groups A, B, and C for 6, 15, and 30 days respectively, the lenses from the guinea pigs in the experimental group were removed. The scleral fibroblasts in each group were cultured, and passaged twice in vitro. The micropipette aspiration technique coupled with a viscoelastic solid model was utilized to investigate the viscoelastic properties of the scleral fibroblasts in normal and myopic guinea pigs. The mechanical behavior of the scleral desmocytes of the LIM and SC groups were compared. RESULTS: The mechanical behavior of the scleral desmocytes was compared between the LIM and SC groups. The Young's modulus at equilibrium and the apparent cellular viscosity of the anterior portion of the sclera in the LIM group at 6 days and 15 days after myopic induction were not significantly different from that of the SC group (P < 0.05). However, the results for the anterior portions of the sclera in the LIM group at 30 days were significantly higher than those of the LIM group at 6 and 15 days, as well as those in the SC group (P < 0.05). The Young's modulus at equilibrium and the apparent cellular viscosity of the extreme posterior portions of the sclera in the LIM group at 6 days after myopic induction not significantly from those of the SC group (P < 0.05). However, the results for the extreme posterior portions of the sclera in the LIM group after 15 days and 30 days were significantly higher than those in the LIM group at 6 days and the SC group (P < 0.05). CONCLUSIONS: The Young's modulus at equilibrium or apparent cellular viscosity of all the anterior portions of the sclera in the LIM group were longer than those in the SC group at 30 days after the induction, and the results for all the extreme posterior portions of the LIM group were larger than those of the SC group on the 15th and 30th day. Therefore, the Young's modulus and apparent viscosity of the anterior and extreme posterior portions of the sclera changed on the 15th and 30th day after induction respectively.

[The effect of curcumin on DNA content, mitochondrial transmembrane potential and calcium of rabbit cultured retinal pigment epithelial cells].

OBJECTIVE: To investigate the Change of DNA content (apoptosis rate), mitochondrial transmembrane potential (DeltaPsim) and calcium (Ca(2+)) of rabbit retinal pigment epithelial (RPE) cells cultured with curcumin. METHODS: It was an experimental study. The RPE cells were dissociated from rabbit eyes and cultured. The RPE cells in the 4(th) passage were divided into 2 groups: curcumin group and control group (10% FBS-EMDM contains 0.05% dimethyl sulfoxide). The curcumin group contained 3 mass concentration: 10 mg/L, 15 mg/L and 20 mg/L. The MTT assay was used to evaluate the inhibition effect of RPE cells cultured with curcumin after 24 h, 48 h, 72 h and 96 h respectively. The IC(50) value in 24 h, 48 h, 72 h and 96 h were gotten by Linear Regression. Flow cytometry was performed to detect the change of DNA content (apoptosis rate), DeltaPsim and Ca(2+) of RPE cells cultured with curcumin (15 mg/L) after 8 h, 24 h, 48 h and 72 h respectively. RESULTS: RPE cells were significantly inhibited by curcumin in a dose dependent and time dependent manner. The IC(50) value of curcumin at 24 h, 48 h, 72 h and 96 h was 29.31 mg/L, 17.50 mg/L, 13.24 mg/L and 10.99 mg/L respectively. Ca(2+) was significantly increased at 8 h, 24 h, 48 h and 72 h after cultured with curcumin (15 mg/L) than that of the control group respectively (t = 7.50, 10.61, 20.74, 21.14, P < 0.01), and DeltaPsim was significantly decreased at 8 h, 24 h, 48 h and 72 h after cultured with curcumin (15 mg/L) than that of the control group respectively (t = 7.50, 11.74, 14.91, 15.29, P < 0.01). There was no change of DNA content in RPE cells at 8h after cultured with curcumin (15 mg/L), but significantly lower than that of the control group at 24 h, 48 h and 72 h respectively (t = 10.00, 14.68, 13.68, P < 0.01). CONCLUSION: The apoptosis of RPE cells induced by curcumin is caused by increase of Ca(2+) and decrease of DeltaPsim that causes decrease of DNA content. The RPE cells are significantly inhibited by curcumin, which may become a potential drug to prevent and treat proliferative vitreoretinopathy.

[The analysis of fundus fluorescein angiography, indocyanine green angiography and hemodynamics of retrobulbar blood vessels in central serous chorioretinopathy].

OBJECTIVE: To analyze the characteristics of the retrobulbar blood vessels' hemodynamics changes and the choroidal circulation disorder, and to observe the relations between retinal pigment epithelium's (RPE) pathological changes and them. METHODS: It was a case control study. For 57 (57 affected eyes and 57 contralateral eyes) unilateral eye affected patients and 25 (50 eyes) normal health adults, we examined ophthalmic arteries (OA), posterior ciliary arteries (PCA) and short posterior ciliary arteries (SPCA) by color Doppler flow Imaging (CDFI), and recorded the peak systolic velocities (PSV), end diastolic velocities (EDV) and resistance indexes (RI) of them. We compared each hemodynamic parameter of the normal eyes with it of the affected eyes and contralateral eyes in patients group respectively, and contrasted them between affected eyes and contralateral eyes of the patients. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed simultaneously on 57 patients with Heidelberg retina angiography, and the images were analyzed in contrast. We used SPSS 12.0 statistics software was used in the study. To the PSV, EDV and RI of the OA, PCA and SPCA in affected eyes and contralateral eyes of the patients, we used paired t-test for the same sample to compare their hemodynamic parameters; to compare normal health adults' eyes with the affected eyes and the contralateral eyes of patients group respectively, we used two-group t-test. When the P-value was less than 0.05, there was a statistical significance. RESULTS: There was a more significant decrease of the hemodynamic parameters in both PSVs and EDVs of temporal PCAs (PSV: t = 3.044, P = 0.005; EDV: t = 3.731, P = 0.001) and temporal SPCAs (PSV: t = 2.822, P = 0.008; EDV: t = 3.194, P = 0.003) compared the patients group's affected eyes with normal health adults group eyes, there was a more significant decrease of them of temporal PCAs (PSV: t = 3.219, P = 0.003; EDV: t = 3.807, P = 0.001) and temporal SPCAs (PSV: t = 3.931, P = 0.000, EDV: t = 3.145, P = 0.003) compared the patients group's contralateral eyes with normal health adults group eyes, and there was a statistical significance of them (P < 0.05). There was no difference in hemodynamic parameters of both PSVs and EDVs of temporal PCAs (PSV: t = 0.608, P = 0.548; EDV: t = 0.122, P = 0.904) and temporal SPCAs (PSV: t = 0.730, P = 0.470; EDV: t = 0.109, P = 0.914) between affected eyes and contralateral eyes of the patients, and there was no statistical significance of them (P > 0.05). The results of FFA and ICGA showed that all the RPE's leaks of 57 affected eyes appeared at the hypofluorescent regions of relative choroids; 52 cases of 57 affected eyes were followed by choroidal vessels dilatation at the early hypofluorescent regions, and appeared hyperfluorescence leakages in the late phase images; At the all regions of RPE's transmitted fluorescences of affected eyes and contralateral eyes, the corresponding choroids showed hyperfluorescence in the late phase images in ICGA; There were no RPE's transmitted fluorescences at the regions of 20 affected eyes and 16 contralateral eyes in FFA, which showed hyperfluoresceince leakages in the late phase images of choroids in ICGA. CONCLUSIONS: CSC is possibly a bilateral disease associated with systemic pathologic conditions. Hypoperfusion and ischemia are the basal characteristics of retrobulbar blood vessels' circulation disorder and choroidal ultracirculation disorder. The damage of RPE is following to the choroidal circulation disorder.

[The inhibition effects of EPA on the proliferation of human vascular endothelial cells].

OBJECTIVE: To investigate inhibition effects and the mechanism of EPA on the proliferation of human umbilical vascular endothelial cells (HUVEC). METHODS: Different concentrations of EPA were added to the cultured HUVEC in vitro. The time cause and does response for the inhibition the cells proliferation in all groups were measured by the MTT assay. Light absorption values and cytostasis ratios in all groups were compared. One-way ANOVA in the SPSS 13.0 version statistical software was used. The effect of EPA on cell cycle, proliferative index (PI) and apoptosis of HUVEC in vitro were observed by Flow Cytometry. chi2-test of R x C contingency table was used as a method for statistical analysis. RESULTS: When the concentration of EPA was equal to or more than 0.15 g/L, MTT assay showed a significant difference of light absorption value in the cultured cell after EPA exposure compared with control, the suppressing effects enhanced as the treatment time increased. The peak time of the inhibition of the cell proliferation induced by EPA was at 60 hours and the effect was last until 72 hours. The proliferative index in the treatment group was 23.9%, which was lower than that in the control group (26.9%). No apoptosis was found in the cell in each group. CONCLUSIONS: EPA plays an important role of inhibition of proliferation of cultured HUVEC in vitro. No apoptosis was induced by the exposure HUVEC to EPA, therefore, it suggests a potential application for clinical trial.

[Effects of amniotic membrane on proliferation of retinal Müller cells: an in vitro experiment with rabbits].

OBJECTIVE: To observe the effects of amniotic membrane on the proliferation of retinal Müller cells. METHODS: (1) Human amniotic membrane was collected form normal lying woman undergoing cesarean section. Müller cells were obtained from the retina of New Zealand rabbit, cultured, and put into 96-well culture plate. Homogenate of human amniotic membrane at different concentrations: 100, 200, 400, and 800 microg/ml respectively were added into the culture fluid for 96 h. The proliferation rate of the Müller cells was measured with MTT method. (2) Müller cells were inoculated in 6-well culture plate with cover slips. Amniotic homogenate of different concentrations was added for 48 hours, and immunohistochemistry was used to detect the expression of proliferating cell nuclear antigen (PCNA). (3) Amniotic homogenate conditioned culture medium on different concentrations was added into the culture fluid of Müller cells for 48 hours. The change of cell cycles was observed by flow cytometry (FCM). RESULTS: Homogenate of human amniotic membrane increased the proliferation rate of the Müller cells dose-dependently and the proliferation rate reached the peak (62.5%) when the concentration homogenate of human amniotic membrane was 800 microg/ml. FCM showed that the amniotic homogenate increased the rate of cells in S phase and decreased the rate of those in G2/M phase and G0/G1 phase concentration-dependently. The proliferation rate of the Müller cells treated with the amniotic homogenate of the same concentration increased time-dependently and peaked 48 h later, and the proliferation rate 96 h later was not significantly different from that 48 h later (F=0.233, 0.007, P=0.492, 0.729). The positive rates of PCNA when the concentrations of the amniotic homogenate were 800 microg/ml and 400 microg/ml respectively (0.84+/-0.07, 0.79+/-0.06) were significantly higher than that of the control group (0.64+/-0.12). CONCLUSION: Amniotic membrane promotes the proliferation on retinal Müller cells dose and time-dependently in vitro.