Diverse roles of macrophages in intraocular neovasculardiseases:a review

Macrophages are involved in angiogenesis, and might also contribute to the pathogenesis of intraocular neovascular diseases. Recent studies indicated that macrophages exert different functions in the process of intraocular neovascularization, and the polarization of M1 and M2 phenotypes plays extremely essential roles in the diverse functions of macrophages. Moreover, a large number of cytokines released by macrophages not only participate in macrophage polarization, but also associate with retinal and choroidal neovascular diseases. Therefore, macrophage might be considered as a novel therapeutic target to the treatment of pathological neovascularization in the eye. This review mainly summarizes diverse roles of macrophages and discusses the possible mechanisms in retinal and choroidal neovascularization.

Prevalence of amblyopia among preschool children in central south China

AIM: To determine the prevalence and factors associated with amblyopia among children aged 30-83 mo in central south of China.METHODS: A population-based, cross-sectional study was conducted in children aged 30-83 mo in Changsha(an urban city) and Zhangjiajie(a rural area) in central south of China. Clinical examinations including ocular alignment, ocular motility, visual acuity(VA), prism cover test, cycloplegic refraction, slit lamp examination and fundus examination were performed by trained study ophthalmologists and optometrists. Unilateral amblyopia was defined as a 2-line difference between eyes with VA<20/32 in the worse eye and with coexisting anisometropia [≥1.00 D spherical eutivalent(SE) for hyperopia, ≥3.00 D SE for myopia, and ≥1.50 D for astigmatism], strabismus, or past or present visual axis obstruction. Bilateral amblyopia was defined as VA in both eyes <20/40(≥ 48-month-old) and <20/50(< 48-month-old), with coexisting hyperopia ≥4.00 D SE, myopia ≤-6.00 D SE, and astigmatism ≥2.50 D, or past or present visual axis obstruction.RESULTS: There were 8042 children enrolled and 7713 children were screened. The amblyopia prevalence in children aged 30-83 mo was 1.09%(95% confidence interval, 0.86%-1.35%) with no age(P=0.81), gender(P=0.46) or area distribution(P=0.93) differences. Of these, 0.68% were unilateral cases and 0.41% were bilateral cases. Underlying causes included anisometropia(40%), binocular refractive error(36%), strabismus(14%) and deprivation(10%). Hyperopia combined with astigmatism was the frequent refractive error for ametropic and anisometropic amblyopia.CONCLUSION: In this rural and urban Chinese population, 1.09% of children with 30-83 mo of age had amblyopia, a prevalence rate similar to that of many other studies. Anisometropia and refractive error are the most common causes of unilateral and bilateral amblyopia respectively.

5-aza-2'-deoxycytidine in the regulation of antioxidant enzymes in retinal endothelial cells and rat diabetic retina

AIM: To investigate the roles of a DNA methyltransferase(DNMT) inhibitor 5-aza-2'-deoxycytidine(5-aza-dC) in the regulation of antioxidant enzymes in diabetic retinopathy(DR) models. METHODS: DNMTs expressions and activity, and changes of two key antioxidant enzymes in DR, MnSOD(encoded by SOD2 gene) and glutathione S-transferase theta 1(GSTT1), were quantified in the isolated human retinal endothelial cells(HRECs) exposed to high glucose(HG) with or without 5-aza-dC treatment. The downstream exacerbating factors including vascular endothelial growth factor(VEGF), intercellular adhesion molecule 1(ICAM-1) and matrix metalloproteinase 2(MMP2), which are implicated in the pathogenesis of DR and closely related to oxidative stress were also analyzed. The key parameters were confirmed in the retina from streptozotocin(STZ) diabetic rats. RESULTS: DNMTs expression and DNMT activity was induced in HRECs exposed to HG. Hyperglycemia decreased MnSOD and GSTT1 expression. 5-aza-dC administration effectively suppressed DNMTs expression and activity and reversed the MnSOD and GSTT1 expression under HG condition. VEGF, ICAM-1 and MMP2 induced by HG were also suppressed by 5-aza-dC treatment. Similar results were observed in the retina from STZ diabetic rats. CONCLUSION: Our findings suggest that DNA methylation may serves as one of the mechanisms of antioxidant defense system disruption in DR progression. Modulation of DNA methylation using pharmaceutic means such as DNMT inhibitors could help maintain redox homeostasis and prevent further progression of DR.

Increased vitreal levels of interleukin-10 in diabetic retinopathy:a Meta-analysis

AIM:To conduct a Meta-analysis for the change of interleukin-10(I1-10)concentration in vitreous samples of patients with diabetic retinopathy(DR).METHODS:Systemic search for literature was conducted from the databases of PubMed,Web of Science and Cochrane Library by August 2019.Statistical analyses including standard mean difference(SMD)and its 95%confidence interval(CI)were performed by using RevMan 5.3 software.RESULTS:Totally 194 studies were screened and finally 11 studies were included in the Meta-ana lysis.The concentration of IL-10 in the DR group was higher than in the control group(P=0.003.SMD:0.77.95%CI:0.25-1.28).Significant heterogeneity was found among all studies(P<0.00001,I^2=92%).The subgroup analysis showed that the concentration of IL-10 increased in vitreous samples from patients with DR compared to the non-DR controls(P=0.004.SMD:1.44.95%CI:0.46-2.42).Moreover,the concentration of IL-10 in samples of proliferative diabetic retinopathy(PDR)patients was significantly higher than that of non-proliferative diabetic retinopathy(NPDR)patients(P=0.01.SMD:0.61.95%CI:0.13-1.08).CONCLUSION:The vitreal concentration of IL-10 is significantly increased in patients with DR.Further studies are needed to reveal the mechanisms of IL-10 in DR.

Identification of altered microRNAs in retinas of mice with oxygen-induced retinopathy

AIM: To identify disease-related miRNAs in retinas of mice with oxygen-induced retinopathy(OIR), and to explore their potential roles in retinal pathological neovascularization. METHODS: The retinal miRNA expression profile in mice with OIR and room air controls at postnatal day 17(P17) were determined through miRNA microarray analysis. Several miRNAs were significantly up-and down-regulated in retinas of mice with OIR compared to controls by quantitative real-time reverse transcription-polymerase chain reaction(qRT-PCR). Two databases including Targetscan7.1 and MirdbV5 were used to predict target genes that associated with those significantly altered mi RNAs in retinas of mice with OIR. Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analyses were also conducted to identify possible biological functions of the target genes. RESULTS: In comparison with room air controls, 3 and 8 miRNAs were significantly up-and down-regulated, respectively, in retinas of mice with OIR. The qRT-PCR data confirmed that mmu-miR-350-3 p and mmu-miR-202-3 p were significantly up-regulated, while mmu-miR-711 and mmu-miR-30 c-1-3 p were significantly down-regulated in mice with OIR compared to controls. GO analysis demonstrated that the identified target genes were related to functions such as cellular macromolecule metabolic process. KEGG pathway analysis showed a group of pathways, such as Wnt signaling pathway, transcriptionalmisregulation in cancer, Mucin type O-glycan biosynthesis, and mitogen-activated protein kinase(MAPK) signaling pathway might be involved in pathological process of retinal neovascularization. CONCLUSION: Our findings suggest that the differentially expressed miRNAs in retinas of mice with OIR might provide potential therapeutic targets for treating retinal neovascularization.

Attenuation of periostin in retinal Müller glia by TNF-α and IFN-γ

AIM: To investigate the regulation and mechanisms of periostin expression in retinal Müller glia, and to explore the relevance to retinal neovascularization. METHODS: The oxygen-induced retinopathy(OIR) mouse model and the human Moorfield/Institute of Ophthalmology-Müller 1(MIO-M1) cell line were used in the study. Immunofluorescence staining was used to determine the distribution and expression of periostin and a Müller glial cell marker glutamine synthetase(GS). Cytokines TNF-α and IFN-γ were added to stimulate the MIO-M1 cells. ShRNA was used to knockdown periostin expression in MIO-M1 cells. Quantitative real-time reverse transcription polymerase chain reaction(qRT-PCR) was conducted to assess the mRNA expression of periostin. RESULTS: Immunofluorescence staining showed that periostin was expressed by MIO-M1 Müller glia. GS-positive Müller glia and periostin increased in OIR retinas, and were partially overlaid. The stimulation of TNF-α and IFN-γ reduced the mRNA expression of periostin significantly and dose-dependently in MIO-M1 cells. Knockdown of periostin reduced mRNA expression of vascular endothelial growth factor A(VEGFA) in MIO-M1 cells, while VEGFA expression was not changed in periostin knock-out OIR retinas. CONCLUSION: Müller glia could be one of the main sources of periostin in the retina, and might contribute to the pathogenesis of retinal neovascularization. Proinflammatory cytokines TNF-α and IFN-γ attenuate the periostin expression in retinal Müller glia, which provides a potential and novel method in treating retinal neovascular diseases.

Role of interferons in diabetic retinopathy

Diabetic retinopathy(DR)is one of the major causes of visual impairment and irreversible blindness in developed regions.Aside from abnormal angiogenesis,inflammation is the most specific and might be the initiating factor of DR.As a key participant in inflammation,interferon-gamma(IFN-γ)can be detected in different parts of the eye and is responsible for the breakdown of the blood-retina barrier and activation of inflammatory cells and other cytokines,which accelerate neovascularization and neuroglial degeneration.In addition,IFN-γis involved in other vascular complications of diabetes mellitus and angiogenesis-dependent diseases,such as diabetic nephropathy,cerebral microbleeds,and age-related macular degeneration.Traditional treatments,such as anti-vascular endothelial growth factor agents,vitrectomy,and laser photocoagulation therapy,are more effective for angiogenesis and not tolerable for every patient.Many ongoing clinical trials are exploring effective drugs that target inflammation.For instance,IFN-αacts against viruses and angiogenesis and is commonly used to treat malignant tumors.Moreover,IFN-αhas been shown to contribute to alleviating the progression of DR and other ocular diseases.In this review,we emphasize the roles that IFNs play in the pathogenesis of DR and discuss potential clinical applications of IFNs in DR,such as diagnosis,prognosis,and therapeutic treatment.

Effect of anti-VEGF treatment on nonperfusion areas in ischemic retinopathy

In recent years,retinal ischemia such as that which occurs in diabetic retinopathy(DR)and retinal vein occlusion(RVO)has become a hotspot of ischemic retinopathy research.High levels of vascular endothelial growth factor(VEGF)are recognized as a major cause of macular edema(ME)in DR and RVO.High concentrations of VEGF in the vitreous can lead to serious retinal ischemia and hypoxia and form retinal nonperfusion areas(NPAs).Different levels of retinal ischemia can represent disease severity and progression.Anti-VEGF therapy as the first-line treatment for ME has been found to be effective in improving vision,but there are still disputes about whether anti-VEGF therapy could improve retinal ischemia and achieve reper fusion of previously developed retinal NPAs.Here,we review and summarize studies of the effects of anti-VEGF drugs on retinal ischemia,especially NPAs.

Knobloch syndrome caused by homozygous frameshift mutation of the COL18A1 gene in a Chinese pedigree

AIM： To explore the clinical feature and genetic etiology of a Chinese Knobloch syndrome family. METHODS： Ocular examinations and magnetic resonance imagings （MRIs） were performed on the family. Whole exome sequencing was conducted on the two patients. Sanger sequencing was utilized to validate the presence of variation in the family as well as in 100 normal controls. Real-time uantitative polymerase chain reaction （PCR） was used to detect the expression level of COL18A1 in peripheral blood lymphocytes of the patients and normal carriers. RESULTS： The affected subjects presented with vision loss, exotropia, cataracts, retinal detachment, and other complications. A homozygous c.4759_4760delCT （p.Leu1587ValfsX72） mutation （rs398122391） in COL18A1 was identified in the two patients, cosegregating with the phenotypes, and did not be detected in 100 normal controls. This mutation caused significant decreased expression of COL18A1 mRNA in the patients. CONCLUSION： The findings strongly indicate that this mutation is the disease-causing mutation. Moreover, this is the first Knobloch syndrome pedigree reported in the Chinese population.

Reactive oxygen species mediates a metabolic memory of high glucose stress signaling in bovine retinal pericytes

AIM: To investigate the role of reactive oxygen species (ROS) and antioxidant mechanism underlying the metabolic memory of bovine retinal pericytes (BRPs) induced by high glucose.METHODS: Effects of high glucose levels and culture time on BRPs viability were evaluated by CCK-8. BRPs were grown in high-glucose media (30 mmol/L) for 4d followed by culture in normal glucose condition (5.6 mmol/L) for 4d in an experimental group. In contrast, in negative and positive control groups, BRPs were grown in either normal-glucose media or high-glucose media for 8d, respectively. The ROS levels, apoptosis, the expression and activity of manganese superoxide dismutase (MnSOD) in BRPs, as well as the protective effect of adeno-associated viral (AAV)-mediated over expression of MnSOD were determined separately by DCHFA, ELISA and Western blot.RESULTS: Comparing the result of cells apoptosis, activity and protein expression of MnSOD and caspase-3, the cell culture system that exposed in sequence in 30 mmol/L and normal glucose for 4d was demonstrated as a suitable model of metabolic memory. Furthermore, delivery of antioxidant gene MnSOD can decrease BRPs apoptosis, reduce activated caspase-3, and reverse hyperglycemic memory by reducing the ROS of mitochondria.CONCLUSION: Increased ROS levels and decreased MnSOD levels may play important roles in pericyte loss of diabetic retinopathy. BRPs cultured in high glucose for 4d followed by normal glucose for 4d could be an appropriate model of metabolic memory. rAAV-MnSOD gene therapy provides a promising strategy to inhibit this blinding disease.

A ten years follow-up case of bilateral idiopathic multifocal retinal pigment epithelium detachments with rhegmatogenous retinal detachment and a literature review

Dear Editor, I am Dr. Yun Li, from the Department of Ophthalmology, the 2^(nd) Xiangya Hospital of Central South University, Changsha, Hunan Province, China. We write to present a case of idiopathic multifocal serous retinal pigment epithelial detachments(RPEDs).

Optical coherence tomography evaluation of retinal nerve fiber layer thickness in non-arteritic anterior ischemic optic neuropathy and primary open angle glaucoma:a systematic review and Meta-analysis

AIM:To assess the differences in average and sectoral peripapillary retinal nerve fiber layer(p RNFL)thickness using spectral domain optical coherence tomography(SD-OCT)in patients with non-arteritic anterior ischemic neuropathy(NAION)compared with those with primary open angle glaucoma(POAG).METHODS:A comprehensive literature search of the Pub Med,Cochrane Library,and Embase databases were performed prior to October,2021.Studies that compared the p RNFL thickness in NAION eyes with that in POAG eyes with matched mean deviation of the visual fields were included.The weighted mean difference(WMD)with 95%confidence interval(CI)was used to pool continuous outcomes.RESULTS:Ten cross-sectional studies(11 datasets)comprising a total of 625 eyes(278 NAION eyes,347 POAG eyes)were included in the qualitative and quantitative analyses.The pooled results demonstrated that the superior p RNFL was significantly thinner in NAION eyes than in POAG eyes(WMD=-6.40,95%CI:-12.22 to-0.58,P=0.031),whereas the inferior p RNFL was significant thinner in POAG eyes than in NAION eyes(WMD=11.10,95%CI:7.06 to 15.14,P≤0.001).No difference was noted concerning the average,nasal,and temporal p RNFL thickness(average:WMD=1.45,95%CI:-0.75 to 3.66,P=0.196;nasal:WMD=-2.12,95%CI:-4.43 to 0.19,P=0.072;temporal:WMD=-1.24,95%CI:-3.96 to 1.47,P=0.370).CONCLUSION:SD-OCT based evaluation of inferior and superior p RNFL thickness can be potentially utilized to differentiate NAION from POAG,and help to understand the different pathophysiological mechanisms between these two diseases.Further longitudinal studies and studies using eight-quadrant or clock-hour classification method are required to validate the obtained findings.

Phosphorylated S6K1 and 4E-BP1 play different roles in constitutively active Rheb-mediated retinal ganglion cell survival and axon regeneration after optic nerve injury

Ras homolog enriched in brain(Rheb) is a small GTPase that activates mammalian target of rapamycin complex 1(mTORC1).Previous studies have shown that constitutively active Rheb can enhance the regeneration of sensory axons after spinal cord injury by activating downstream effectors of mTOR.S6K1 and4E-BP1 are important downstream effectors of mTORC1.In this study,we investigated the role of Rheb/mTOR and its downstream effectors S6K1 and 4E-BP1in the protection of retinal ganglion cells.We transfected an optic nerve crush mouse model with adeno-associated viral 2-mediated constitutively active Rheb and observed the effects on retinal ganglion cell survival and axon regeneration.We found that overexpression of constitutively active Rheb promoted survival of retinal ganglion cells in the acute(14 days) and chronic(21 and 42 days) stages of injury.We also found that either co-expression of the dominant-negative S6K1mutant or the constitutively active 4E-BP1 mutant together with constitutively active Rheb markedly inhibited axon regeneration of retinal ganglion cells.This suggests that mTORC1-mediated S6K1 activation and 4E-BP1 inhibition were necessary components for constitutively active Rheb-induced axon regeneration.However,only S6K1 activation,but not 4E-BP1 knockdown,induced axon regeneration when applied alone.Furthermore,S6K1 activation promoted the survival of retinal ganglion cells at 14 days post-injury,whereas 4E-BP1 knockdown unexpectedly slightly decreased the survival of retinal ganglion cells at 14 days postinjury.Ove rexpression of constitutively active 4E-BP1 increased the survival of retinal ganglion cells at 14 days post-injury.Likewise,co-expressing constitutively active Rheb and constitutively active 4E-BP1 markedly increased the survival of retinal ganglion cells compared with overexpression of constitutively active Rheb alone at 14 days post-injury.These findings indicate that functional 4E-BP1 and S6K1 are neuroprotective and that 4E-BP1 may exert protective effects through a pathway at least partially independent of Rhe b/mTOR.Together,our results show that constitutively active Rheb promotes the survival of retinal ganglion cells and axon regeneration through modulating S6K1 and 4E-BP1 activity.Phosphorylated S6K1 and 4E-BP1 promote axon regeneration but play an antagonistic role in the survival of retinal ganglion cells.

Phacoemulsification with or without goniosynechialysis for angle-closure glaucoma: a global Meta-analysis based on randomized controlled trials

AIM: To compare the benefits and potential harms of routine phacoemulsification(phaco) alone and combined surgery with goniosynechialysis(GSL) for angle-closure glaucoma(ACG) and coexisting lens opacity, as shown in different randomized controlled trials(RCTs).METHODS: A systematic review was conducted searching several databases including PubMed, Cochrane Library, EMBASE, ClinicalTrials.gov from the inception to September 2018 for RCTs with data published on the effects and safety of phaco and intraocular lens implantation combined with GSL or routine cataract surgery alone. Several studies were recruited which reported data at baselines and postoperative follow-up, including the mean values of postoperative intraocular pressure(IOP) and mean numbers of antiglaucoma medications using postoperatively. The numbers of complications happening were also included. Fixedeffect and random-effect models were applied, and the quality of evidence was evaluated.RESULTS: Analysis of the seven included RCTs, with a total number of 321 participants(358 eyes) diagnosed with ACG and cataract, received a solo procedure(phaco group) or a combined surgery(phaco-GSL group) randomly, and follow-up periods ranging from 2 to 12 mo postoperatively. The involved studies showed that the mean value of IOP between the two groups at 3(four studies, one study follow-up at 2 mo postoperative was included), 6, 12 mo postoperative were not significantly different. Only two studies reported the change in IOP value at 12 mo compared with baseline but showed nosignificant differences between the two interventions. Although three studies did not have the significant difference in the number of medications using to reduce IOP at 3 mo postoperatively, two studies reported that the participants using fewer anti-glaucoma medications at 12 mo postoperative in the phaco group than in the phacoGSL surgery group.CONCLUSION: The analysis provides a low to moderatequality evidence that phaco-GSL surgery lead to an equivalent IOP-lowering effect. The phaco-GSL surgery may not help patients to reduce the consumption of antiglaucoma eyedrops in the long period. The results of this analysis suggested that additional GSL may not be necessary for primary angle closure glaucoma(PACG) patients. Further studies, especially RCTs with more participants and longer follow-up time were needed to provide more sufficient data.

A novel mutation in FBN1 gene in autosomal dominant Marfan syndrome and macular degeneration in a Chinese consanguineous family

AIM: To report a novel mutation in FBN1 gene in a Chinese consanguineous family with common Marfan syndrome(MFS) phenotype and an unusual bilateral macular degeneration. METHODS: Ophthalmic, cardiovascular and systemic examinations were performed, and genomic DNA extracted from all living family members. The 24-32 exon mutations of FBN1 gene were screened by Sanger Sequencing in all family members and 100 unrelated healthy Chinese individuals. RESULTS: In the four-generation family, classic MFS phenotypes were observed in all 5 patients, 2 of them had peculiar phenotype of bilateral macular degeneration. Mutation screening in FBN1 identified a heterozygous missense mutation(c.3932 A>G, p.Y1311 C) with co-segregation. This mutation was found with the MFS phenotypes in all 5 patients but not in unaffected members or unrelated controls. CONCLUSION: A Chinese consanguineous MFS family with uncommon bilateral macular degeneration and an unreported c.3932 A>G mutation in FBN1 was identified. Our finding expands the FBN1 mutation spectrum and its possible role in the pathogenesis of Marfan syndrome.

Ocular manifestations and SARS-CoV-2 detection in tears and conjunctival scrape from non-severe COVID-19 patients

AIM:To explore the ocular features of corona virus disease(COVID)-19 and severe acute respiratory syndrome coronavirus(SARS-CoV)-2 detection in tears and conjunctival scrapes in non-severe COVID-19 patients.METHODS:This is a multicenter observational clinical study with no intervention conducted from Jan 25th to March 1st,2020.Clinical data and samples of tears and conjunctival scraping were collected in consecutive laboratory-confirmed,non-severe COVID-19 patients from three hospitals.COVID-19 virus was analyzed by real-time reverse transcriptase polymerase chain reaction(RT-PCR)kits.RESULTS:Totally 255 laboratory-confirmed,non-severe COVID-19 patients were recruited for ocular manifestation investigation.Of them,54.9%were females,with a mean age of 49.4 y.None of the patients has evidence of uveitis;11 patients(4.3%)complained of mild asthenopia;2(0.8%)had mild conjunctival congestion and serous secretion.Twenty-five of them had performed tears and conjunctival scrape for COVID-19 virus detection,with 4 yield possible positive results in the nucleoprotein gene.One of them were asymptomatic with normal chest CT and positive pharyngeal swab result.CONCLUSION:Ocular manifestations are neither common nor specific in non-severe COVID-19 patients.Meanwhile,COVID-19 virus nucleotides can be detected in the tears and conjunctival scrape samples,warranting further research on the transmissibility by the ocular route.

Severe Sturge-Weber syndrome in a 9-year-old boy: a great challenge

Dear Editor,We present a severe Sturge-Weber syndrome(SWS)in a boy with Mongolian spot,congenital glaucoma,seizures,and intelligent disability.During the hospital,the boy was admitted Pediatrics Department and Ophthalmology Department to control the seizure of episode and glaucoma respectively.

Solitary fibrous tumor: a 10-year retrospective analysis with several rare cases

To the Editor:Solitary fibrous tumors(SFTs)are mesenchymal neoplasms and were first described in pleura,then subsequently found in extrapleural organs,such as peritoneum,lung,parotid gland,paranasal sinuses,orbit,skin,and intracranial areas.1 However,extrapleural SFTs are limited to isolated case reports.Because of the rarity of them,the related information is far from sufficient and thus,leading this tumor under fully recognized.According to the World Health Organization(WHO)classification,SFTs are pluripotent neoplasms that could be benign,intermediate,or malignant.All of above drive us to further understand the epidemiology,clinical characteristics,medical therapy,and prognosis of this disease.