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.

A pilot study on vitrectomy combined with scleral shortening for eyes with myopic macular retinoschisis-2y follow-up results.

AIM: To evaluate the effect of vitrectomy combined with scleral shortening for eyes with myopic macular retinoschisis. METHODS: Thirty-seven patients with myopic macular retinoschisis who underwent pars plana vitrectomy (PPV) combined with scleral shortening were reviewed. Axial length (AL), the height of macular retinoschisis, the height of retinal detachment if existed, the diameter of macular hole if existed and best corrected visual acuity (BCVA) were obtained. The preoperative and postoperative parameters were compared. RESULTS: At postoperative 24mo, the mean AL and height of macular retinoschisis were reduced significantly by 0.79 mm and 256.51 µm (t=8.064, P<0.0001; Z=-5.086, P<0.0001) respectively. In addition, the mean height of retinal detachment and diameter of macular hole were also reduced significantly by 365.38 µm and 183.68 µm (Z=-4.457, P=0.000008; Z=-2.983, P=0.003) respectively. Meanwhile, the postoperative BCVA was improved markedly (Z=-2.126, P=0.033). CONCLUSION: Vitrectomy combined with scleral shortening is an effective surgical method for eyes with myopic macular retinoschisis, whether or not macular hole and retinal detachment are present.

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.

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.

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.

Gene silencing of two acetylcholinesterases reveals their cholinergic and non-cholinergic functions in Rhopalosiphum padi and Sitobion avenae.

BACKGROUD: The function of acetylcholinesterase (AChE) is to terminate synaptic transmission by hydrolysing the neurotransmitter acetylcholine (ACh) in the synaptic cleft, and thus it is an effective target for organophosphate (OP) and carbamate (CB) insecticides. RESULTS: The transcript levels of the four Ace genes were dramatically suppressed by injection of their respective dsRNA in Rhopalosiphum padi and Sitobion avenae. However, the AChE activity changes in the Ace1 knockdown aphids were consistent with the significant transcript level changes of Ace1 genes in these aphids, but not for Ace2. Bioassay results indicated that the suppression of RpAce1 increased its susceptibilities to pirimicarb and malathion, and SaAce1 silencing also increased susceptibility to pirimicarb in S. avenae, whereas the knockdowns of RpAce2 and SaAce2 had a slight effect on their susceptibilities. The knockdown of Ace1 genes also caused significant reductions in fecundity in the aphids of their parental generation. CONCLUSIONS: These results suggest that AChE1 is a predominant cholinergic enzyme and is the target of anticholinesterase insecticides in both R. padi and S. avenae. It also plays a non-cholinergic role in fecundity of these aphids. AChE2 may also be important for the toxicological function, although its importance appeared to be lower than that of AChE1.

Genetic diversity of Sitobion avenae (Homoptera: Aphididae) populations from different geographic regions in China.

Sitobion avenae is a major agricultural pest of wheat in China. Using microsatellite markers, we studied the potential gene flow, genetic diversity, genetic differentiation, and genetic structure of seven S. avenae populations from different regions of China (Beijing, Hebei, Henan, Hubei, Jiangsu, Shandong, and Shanxi provinces). The populations from Henan, Shandong, and Jiangsu showed high levels of genic and genotypic diversity. By contrast, the genic diversity in the Beijing and Hebei populations was much lower. Despite this low genic diversity, the genotypic diversity of the Beijing population was higher than that of all of the other populations, except those from Jiangsu and Shandong. Overall, the genetic divergence among the seven S. avenae populations tested was high, though there was almost no differentiation between the Shandong and Henan populations. We observed significant negative correlation between the strength of gene flow and the geographic distances among populations. Based on genetic analysis, the seven S. avenae populations studied can be divided into four distinct clusters; (i) Hubei, (ii) Shanxi, (iii) Beijing and Hebei, and (iv) Shandong, Henan, and Jiangsu. The present results provide a basis for potentially optimizing integrated pest management (IPM) programs in China, through adapting control methods that target biological traits shared by various populations of the same genotype.

Oral delivery mediated RNA interference of a carboxylesterase gene results in reduced resistance to organophosphorus insecticides in the cotton Aphid, Aphis gossypii Glover.

BACKGROUND: RNA interference (RNAi) is an effective tool to examine the function of individual genes. Carboxylesterases (CarE, EC 3.1.1.1) are known to play significant roles in the metabolism of xenobiotic compounds in many insect species. Previous studies in our laboratory found that CarE expression was up-regulated in Aphis gossypii (Glover) (Hemiptera: Aphididae) adults of both omethoate and malathion resistant strains, indicating the potential involvement of CarE in organophosphorus (OP) insecticide resistance. Functional analysis (RNAi) is therefore warranted to investigate the role of CarE in A. gossypii to OPs resistance. RESULT: CarE expression in omethoate resistant individuals of Aphis gossypii was dramatically suppressed following ingestion of dsRNA-CarE. The highest knockdown efficiency (33%) was observed at 72 h after feeding when dsRNA-CarE concentration was 100 ng/µL. The CarE activities from the CarE knockdown aphids were consistent with the correspondingly significant reduction in CarE expression. The CarE activity in the individuals of control aphids was concentrated in the range of 650-900 mOD/per/min, while in the individuals of dsRNA-CarE-fed aphids, the CarE activity was concentrated in the range of 500-800 mOD/per/min. In vitro inhibition experiments also demonstrated that total CarE activity in the CarE knockdown aphids decreased significantly as compared to control aphids. Bioassay results of aphids fed dsRNA-CarE indicated that suppression of CarE expression increased susceptibility to omethoate in individuals of the resistant aphid strains. CONCLUSION: The results of this study not only suggest that ingestion of dsRNA through artificial diet could be exploited for functional genomic studies in cotton aphids, but also indicate that CarE can be considered as a major target of organophosphorus insecticide (OPs) resistance in A. gossypii. Further, our results suggest that the CarE would be a propitious target for OPs resistant aphid control, and insect-resistant transgenic plants may be obtained through plant RNAi-mediated silencing of insect CarE expression.

[Experimental choroidal neovascularization is inhibited by subretinal administration of Endostatin].

OBJECTIVE: Endostatin is an endogeneous angiogenesis inhibitor. The purpose of this study was to investigated the effect of Endostatin on the eyes of rats with experimental choroidal neovascularization (CNV). METHODS: Experimental CNV was induced by laser photocoagulation. Animals were given subretinal injections of recombinant human Endostatin 20 microl (5 g/L) or 0.9% chlorine sodium. The intensity of fluorescein leakage from the photocoagulated lesions was studied 13 days after photocoagulation. The area of CNV at each rupture site was measured using high molecular weight FITC-dextran (MW 2 x 10(6)) for high resolution angiography in RPE-choroid-sclera flat mounts. In addition, 8 eyes in each group were removed and fixed 14 days after photocoagulation, cut into thin sections. The sections were examined by light microscopy. Immunolocalization of Endoglin (CD105) and factor VIII on sections of CNV lesions was studied by immunohistochemical evaluation. RESULTS: After Endostatin injection, fluorescein leakage from the CNV lesions decreased significantly compared with the control eyes. The average area of CNV at sites of the Bruch's membrane rupture showed significant difference in eyes injected with Endostatin compared with control eyes. Endothelial cells demonstrated strong immunoreactivity of CD105 and factor VIII in CNV lesions of control eyes. CD105-positive cell were not detected in normal chorioretinal tissues. CONCLUSIONS: The development of CNV can be inhibited by injection of Endostatin, which suggest that Endostatin may be beneficial in treating CNV and that further studies can be considered to evaluate this possibility.