Efficacy and Safety of Biosimilar QL1207 vs. the Reference Aflibercept for Patients with Neovascular Age-Related Macular Degeneration: A Randomized Phase 3 Trial.

INTRODUCTION: This trial aimed to compare the efficacy and safety between biosimilar QL1207 and the reference aflibercept for the treatment of neovascular age-related macular degeneration (nAMD). METHODS: This randomized, double-blind, phase 3 trial was conducted at 35 centers in China. Patients aged ≥ 50 years old with untreated subfoveal choroidal neovascularization secondary to nAMD and best-corrected visual acuity (BCVA) letter score of 73-34 were eligible. Patients were randomly assigned to receive intravitreous injections of QL1207 or aflibercept 2 mg (0.05 ml) in the study eye every 4 weeks for the first 3 months, followed by 2 mg every 8 weeks until week 48, stratified by baseline BCVA ≥ or < 45 letters. The primary endpoint was BCVA change from baseline at week 12. The equivalence margin was ± 5 letters. The safety, immunogenicity, pharmacokinetics (PK), and plasma vascular endothelial growth factor (VEGF) concentration were also evaluated. RESULTS: A total of 366 patients were enrolled (QL1207 group, n = 185; aflibercept group, n = 181) from Aug 2019 to Jan 2022 with comparable baseline characteristics. The least-squares mean difference in BCVA changes was - 1.1 letters (95% confidence interval - 3.0 to 0.7; P = 0.2275) between the two groups, within the equivalence margin. The incidences of treatment-emergent adverse events (TEAE; QL1207: 71.4% [132/185] vs. aflibercept: 71.8% [130/181]) and serious TEAE (QL1207: 14.1% [26] vs. aflibercept: 12.7% [23]) appeared comparable between treatment groups, and no new safety signal was found. Anti-drug antibody, PK profiles, and VEGF concentration were similar between the two groups. CONCLUSIONS: QL1207 has equivalent efficacy to aflibercept for nAMD with similar safety profiles. It could be used as an alternative anti-VEGF agent for clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05345236 (retrospectively registered on April 25, 2022); National Medical Products Administration of China: CTR20190937 (May 20, 2019).

Phosphoinositide 3-kinase as a therapeutic target in angiogenic disease.

Phosphoinositide 3-kinases (PI3Ks) generate lipids that control multitudinous intracellular cell signaling events which participate in cell survival and proliferation. In addition, PI3K signaling also contributes to metabolism, immunity, angiogenesis and cardiovascular homeostasis, and many diseases. The diverse actions of PI3K stem from the existence of their various isoforms and a variety of protein effectors. Hence, PI3K isoform-specific inhibitors have already achieved a wonderful effect on treating cancer. Herein, we summarize the molecular mechanism of PI3K inhibitors in preventing the permeability of vessels and neovascularization. Additionally, we briefly illustrate how PI3K signaling modulates blood vessel growth and discuss the different roles that PI3K isoforms play in angiogenesis.

Attenuation of Microglial Activation and Pyroptosis by Inhibition of P2X7 Pathway Promotes Photoreceptor Survival in Experimental Retinal Detachment.

Purpose: Photoreceptor (PR) death is the ultimate cause of irreversible vision loss in retinal detachment (RD). Although microglial infiltration in the subretinal space (SRS) was observed after RD, the molecular mechanism underlying microglial activation and the outcomes of infiltrating microglia remain unclear. We aimed to uncover the mechanism of initiation of microglial activation to help explore potential therapy to promote PR survival. Methods: An RD model was conducted by injecting sodium hyaluronate into SRS of C57BL/6J wild type mice. Adenosine triphosphate (ATP) was measured by a ATP Microplate Assay Kit. Bioinformatics analysis was used to evaluate the upregulated receptor relating to ATP binding in human datasets and mouse transcriptomes of RD. Expression of P2X7, its downstream signaling pathways, and microglial pyroptosis were confirmed by qPCR, WB, and immunofluorescence in vivo and in vitro. The cell viability of PR was measured by cell counting kit-8. Brilliant Blue G, a P2X7 antagonist, was subretinally or intraperitoneally injected to inhibit microglial activation in vivo and was applied for microglia cell line treatment in vitro. The decrease in microglial activation and pyroptosis was detected by immunofluorescence and WB. The protective effect on PR was measured by hematoxylin and eosin staining, TUNEL assay, and electroretinogram analysis. Results: The results showed that extracellular ATP released in the SRS after RD triggered P2X7 activation and attracted microglia. The downstream cascade of inflammasome activation induced by P2X7 activation contributed to microglial pyroptosis and then to PR death. ATP-activated microglia led to PR death in vitro. P2X7 blockade rescued PR morphologically and functionally by inhibiting microglial activation and pyroptosis. Conclusions: These results elucidate that ATP-induced P2X7-mediated microglial activation leads to microglial pyroptosis, contributing to PR death. Appropriate inhibition of microglial pyroptosis might serve as a pharmacotherapeutic strategy for decreasing PR death in RD.

Intravitreal corticosteroids for diabetic macular edema: a network meta-analysis of randomized controlled trials.

BACKGROUND: To evaluate the efficacy and safety of different intravitreal corticosteroids for treating diabetic macular edema (DME). METHODS: Four databases were systematically searched for randomized controlled trials comparing different intravitreal corticosteroids for treating DME. The primary outcome was the change in best-corrected visual acuity (BCVA) within 6 months after the first injection (short-term BCVA). Secondary outcomes were the change in BCVA over 1 year (long-term BCVA) and changes in central macular thickness (CMT) and intraocular pressure (IOP) within 6 months after the first injection. Network meta-analysis was performed to aggregate the results from the individual studies. RESULTS: Nineteen trials involving 2839 eyes were included. Intravitreal triamcinolone acetonide (TA) injections (≥ 8 mg and 4-8 mg), fluocinolone acetonide (FA) implants (0.5 µg/day) and dexamethasone (DEX) implants (700 µg) improved short-term BCVA (mean changes in logMAR [95% confidence interval] - 0.27 [- 0.40, - 0.15]; - 0.12 [- 0.18, - 0.06]; - 0.10 [- 0.21, - 0.01]; and - 0.06 [- 0.11, - 0.01]). Intravitreal TA injections (4 mg, multiple times), FA implants (0.5 µg/day and 0.2 µg/day), and DEX implants (350 µg) improved long-term BCVA (mean changes in logMAR [95% confidence interval] - 0.11 [- 0.21, - 0.02]; - 0.09 [- 0.15, - 0.03]; - 0.09 [- 0.14, - 0.02]; and - 0.04 [- 0.07, - 0.01]). All intravitreal corticosteroids reduced CMT, and different dosages of TA did not show significant differences in increasing IOP. CONCLUSIONS: Intravitreal corticosteroids effectively improved BCVA in DME patients, with higher dosages showing greater efficacies. TA was not inferior to FA or DEX and may be considered a low-cost alternative choice for DME patients. The long-term efficacy and safety of different corticosteroids deserve further investigation. Trial registration Prospectively registered: PROSPERO, CRD42020219870.

Characteristics of neural growth and cryopreservation of the dorsal root ganglion using three-dimensional collagen hydrogel culture versus conventional culture.

In vertebrates, most somatosensory pathways begin with the activation of dorsal root ganglion (DRG) neurons. The development of an appropriate DRG culture method is a prerequisite for establishing in vitro peripheral nerve disease models and for screening therapeutic drugs. In this study, we compared the changes in morphology, molecular biology, and transcriptomics of chicken embryo DRG cultured on tissue culture plates (T-DRG) versus three-dimensional collagen hydrogels (C-DRG). Our results showed that after 7 days of culture, the transcriptomics of T-DRG and C-DRG were quite different. The upregulated genes in C-DRG were mainly related to neurogenesis, axon guidance, and synaptic plasticity, whereas the downregulated genes in C-DRG were mainly related to cell proliferation and cell division. In addition, the genes related to cycles/pathways such as the synaptic vesicle cycle, cyclic adenosine monophosphate signaling pathway, and calcium signaling pathway were activated, while those related to cell-cycle pathways were downregulated. Furthermore, neurogenesis- and myelination-related genes were highly expressed in C-DRG, while epithelial-mesenchymal transition-, apoptosis-, and cell division-related genes were suppressed. Morphological results indicated that the numbers of branches, junctions, and end-point voxels per C-DRG were significantly greater than those per T-DRG. Furthermore, cells were scattered in T-DRG and more concentrated in C-DRG, with a higher ratio of 5-ethynyl-2'-deoxyuridine (EdU)-positive cells in T-DRG compared with C-DRG. C-DRG also had higher S100 calcium-binding protein B (S100B) and lower α-smooth muscle actin (α-SMA) expression than T-DRG, and contained fewer terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells after 48 hours of serum starvation. After cryopreservation, C-DRG maintained more intact morphological characteristics, and had higher viability and less TUNEL-positive cells than T-DRG. Furthermore, newly formed nerve bundles were able to grow along the existing Schwann cells in C-DRG. These results suggest that C-DRG may be a promising in vitro culture model, with better nerve growth and anti-apoptotic ability, quiescent Schwann cells, and higher viability. Results from this study provide a reference for the construction, storage, and transportation of tissue-engineered nerves. The study was approved by the Ethics Committee of Aier School of Ophthalmology, Central South University, China (approval No. 2020-IRB16), on March 15, 2020.

Normal vitreous promotes angiogenesis via activation of Axl.

Vitreous has been reported to prevent tumor angiogenesis, but our previous findings indicate that vitreous activate the signaling pathway of phosphoinositide 3-kinase (PI3K)/Akt, which plays a critical role in angiogenesis. The goal of this research is to determine which role of vitreous plays in angiogenesis-related cellular responses in vitro. We found that in human retinal microvascular endothelial cells (HRECs) vitreous activates a number of receptor tyrosine kinases including Anexelekto (Axl), which plays an important role in angiogenesis. Subsequently, we discovered that depletion of Axl using CRISPR/Cas9 and an Axl-specific inhibitor R428 suppress vitreous-induced Akt activation and cell proliferation, migration, and tuber formation of HRECs. Therefore, this line of research not only demonstrate that vitreous promotes angiogenesis in vitro, but also reveal that Axl is one of receptor tyrosine kinases to mediate vitreous-induced angiogenesis in vitro, thereby providing a molecular basis for removal of vitreous as cleanly as possible when vitrectomy is performed in treating patients with proliferative diabetic retinopathy.

Normal vitreous promotes angiogenesi via the epidermal growth factor receptor.

Vitreous, a transparent tissue in our body, contains anti-angiogenesis factors. Our previous work reported that vitreous activates the signaling pathway of epidermal growth factor receptor (EGFR), which plays a critical role in angiogenesis. The aim of this study was to determine the role of EGFR in vitreous-induced angiogenesis-related cellular responses in vitro. Using a pharmacologic and molecular approach, we found that vitreous increased proliferation and migration via EGFR in human umbilical vein endothelial cells (HUVECs). Furthermore, we demonstrated that vitreous promoted tube formation via EGFR in HUVECs. Subsequently, depletion of EGFR using CRISPR/Cas9 and blockage with EGFR inhibitor AG1478 suppressed vitreous-induced Akt activation and cell proliferation, migration, and tube formation in HUVECs. The significance of the angiogenic effect derived from vitreous demonstrates the importance of vitreous in the ocular physiology and the pathobiology of angiogenesis-related ophthalmic diseases, such as proliferative diabetic retinopathy.

Transcriptomic Analysis of the Developmental Similarities and Differences Between the Native Retina and Retinal Organoids.

Purpose: We performed a bioinformatic transcriptome analysis to determine the alteration of gene expression between the native retina and retinal organoids in both mice and humans. Methods: The datasets of mouse native retina (GSE101986), mouse retinal organoids (GSE102794), human native retina (GSE104827), and human retinal organoids (GSE119320) were obtained from Gene Expression Omnibus. After normalization, a principal component analysis was performed to categorize the samples. The genes were clustered to classify them. A functional analysis was performed using the bioinformatics tool Gene ontology enrichment to analyze the biological processes of selected genes and cellular components. Results: The development of retinal organoids is slower than that in the native retina. In the early stage, cell proliferation predominates. Subsequently, neural differentiation is dominant. In the later stage, the dominant differentiated cells are photoreceptors. Additionally, the fatty acid metabolic process and mitochondria-related genes are upregulated over time, and the glycogen catabolic process and activin receptors are gradually downregulated in human retinal organoids. However, these trends are opposite in mouse retinal organoids. There are two peaks in mitochondria-related genes, one in the early development period and another during the photoreceptor development period. It takes about five times longer for human retinal development to achieve similar levels of mouse retinal development. Conclusions: Our study reveals the similarities and differences in the developmental features of retinal organoids as well as the corresponding relationship between mouse and human retinal development.

Identifying circRNA-associated-ceRNA networks in retinal neovascularization in mice.

Retinal neovascularization is a complication which caused human vision loss severely. It has been shown that circular RNAs (circRNAs) play essential roles in gene regulation. However, circRNA expression profile and the underlying mechanisms in retinal neovascular diseases remain unclear. In the present study, we identified altered circRNAs in the retinas of oxygen-induced retinopathy (OIR) mouse model by microarray profiling. Microarray analysis revealed that 539 circRNAs were significantly altered in OIR retinas compared with controls. Among them, 185 up-regulated and 354 down-regulated circRNAs were identified. The expression levels of 4 altered circRNAs including mmu_circRNA_002573, mmu_circRNA_011180, mmu_circRNA_016108 and mmu_circRNA_22546 were validated by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Bioinformatic analysis with validated circRNAs such as competing endogenous RNA (ceRNA) regulatory networks with Gene Ontology (GO) enrichment analysis demonstrated that qRT-PCR validated circRNAs were associated with cellular process, cell part and phosphoric ester hydrolase activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that MAPK signaling pathway and renin-angiotensin system were related to validated circRNAs, suggesting these pathways may participate in pathological angiogenesis. The results together suggested that circRNAs were aberrantly expressed in OIR retinas and may play potential roles in retinal neovascular diseases.

Aberrant DNA methylation of mTOR pathway genes promotes inflammatory activation of immune cells in diabetic kidney disease.

DNA methylation has been implicated in the pathogenesis of diabetic kidney disease (DKD), but the underlying mechanisms remain unclear. In this study, we tested the hypothesis that aberrant DNA methylation in peripheral immune cells contributes to DKD progression. We showed that levels of DNA methyltransferase 1 (DNMT1), a key enzyme for DNA methylation, were increased along with inflammatory activity of peripheral blood mononuclear cells in DKD patients. Inhibition of DNMT1 with 5-aza-2'-deoxycytidine (5-Aza) markedly increased the proportion of CD4+CD25+ regulatory T cells in peripheral blood mononuclear cells in culture and in diabetic animals. Adoptive transfer of immune cells from 5-Aza-treated animals showed beneficial effects on the host immune system, resulting in a significant improvement of DKD. Using genome-wide DNA methylation assays, we identified the differentially methylated cytosines in the promoter regions of mammalian target of rapamycin (mTOR) regulators in peripheral blood mononuclear cells of diabetic patients. Further, mRNA arrays confirmed the consistent induction of genes expressed in the mTOR pathway. Importantly, down-regulation of DNMT1 expression via RNA interference resulted in prominent cytosine demethylation of mTOR negative regulators and subsequent decrease of mTOR activity. Lastly, modulation of mTOR resulted in changes in the effect of 5-aza on diabetic immune cells. Thus, up-regulation of DNMT1 in diabetic immune cells induces aberrant cytosine methylation of the upstream regulators of mTOR, leading to pathogenic activation of the mTOR pathway and consequent inflammation in diabetic kidneys. Hence, this study highlights therapeutic potential of targeting epigenetic events in immune system for treating DKD.

LncRNA-MALAT1 promotes neovascularization in diabetic retinopathy through regulating miR-125b/VE-cadherin axis.

Background: Diabetic retinopathy (DR) is currently the leading cause of blindness and visual disability in adults with diabetes mellitus (DM). Neovascularization has been identified as an important clinical property in DR, however, the exact mechanisms in DR neovascularization are still unclear and need further elucidation.Methods: Quantitative real-time PCR (qRT-PCR) was conducted to detect the expression level of long non-coding RNA (lncRNA)-metastasis associated lung adenocarcinoma transcript 1 (MALAT1), miR-125b and vascular endothelial-cadherin (VE-cadherin) in human retina microvascular endothelial cells (hRMECs) treated with high glucose (HG). Luciferase assay was used to detect interaction of MALAT1 with miR-125b and miR-125b with VE-cadherin. MTT assay, transwell assay, tube formation assay and vascular permeability assay were conducted to detect the cell viability, migration tube formation ability and permeability of hRMECs, respectively. ELISA was used to examine the release of VE-cadherin and vascular endothelial growth factor (VEGF). Western blotting was used to access the protein expression of VE-cadherin, VEGF, ß-catenin, matrix metalloproteinase (MMP) 2 (MMP2) and MMP9.Results: MALAT1 and VE-cadherin were up-regulated while miR-125b was down-regulated in hRMECs treated with HG. MALAT1 could competitively bind to miR-125b against VE-cadherin at the site of 3'-untranslated region (3'-UTR), leading to the up-regulation of VE-cadherin. Knockdown of MALAT1 inhibited the proliferation, migration, tube formation and vascular permeability of hRMECs induced by HG through up-regulating miR-125b. Furthermore, we found the deletion of MALAT1 suppressed the VE-cadherin/ß-catenin complex and neovascularization related proteins expression, which was up-regulated by HG.Conclusion: Knockdown of MALAT1 inhibited cell proliferation, migration and angiogenesis of hRMECs via suppressing the VE-cadherin/ß-catenin complex through targeting miR-125b. Inhibition of MALAT1 may serve as a potential target for anti-angiogenic therapy for DR.

Long non-coding RNA H19 regulates viability and metastasis, and is upregulated in retinoblastoma.

Retinoblastoma is the most common type of intraocular pediatric malignant tumor, which typically affects children <6 years of age. However, the underlying molecular mechanisms of retinoblastoma progression remain unclear. The aim of the present study was to investigate the function of long non-coding RNA (lncRNA) H19 in retinoblastoma clinical samples and cell lines, using reverse transcription-quantitative polymerase chain reaction, western blotting, colony formation, MTT, fluorescence activated cell sorting, cell invasion and migration, and in vivo growth assays. The results demonstrated that H19 may serve a critical oncogenic function in the progression of retinoblastoma, as lncRNA H19 levels were markedly increased in retinoblastoma cells and tissues compared with corresponding controls. In addition, patients with retinoblastoma with increased lncRNA H19 expression experienced poorer survival time compared with those with decreased lncRNA H19 levels. Knockdown of lncRNA H19 significantly suppressed retinoblastoma cell proliferation, migration and invasion in vitro and in vivo. Furthermore, lncRNA H19 expression was also associated with multiple proteins, including cyclin-dependent kinase 1, B-cell lymphoma-associated X protein, apoptosis regulator, tumor protein p53, vimentin, cadherin 13 and matrix metallopeptidase 9. In conclusion, lncRNA H19 may serve an important function in tumorigenesis and may be a potential target for therapy and prognosis in retinoblastoma.

Diverse roles of macrophages in intraocular neovascular diseases: 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.

Subretinal Injection: A Review on the Novel Route of Therapeutic Delivery for Vitreoretinal Diseases.

Compared to intravitreal injection, subretinal injection has more direct effects on the targeting cells in the subretinal space, which provides a new therapeutic method for vitreoretinal diseases, especially when gene therapy and/or cell therapy is involved. To date, subretinal delivery has been widely applied by scientists and clinicians as a more precise and efficient route of ocular drug delivery for gene therapies and cell therapies including stem cells in many degenerative vitreoretinal diseases, such as retinitis pigmentosa, age-related macular degeneration, and Leber's congenital amaurosis. However, clinicians should be aware of adverse events and possible complications when performing subretinal delivery. In the present review, the subretinal injection used in vitreoretinal diseases for basic research and clinical trials is summarized and described. Different methods of subretinal delivery, as well as its benefits and challenges, are also briefly introduced.

Mouse Müller Cell Isolation and Culture.

Müller cells are the major supportive and protective glial cells across the retina. Unlike in fish, they have lost the capacity to regenerate the retina in mammals. But, mammalian Müller cells still retain certain retinal stem cell properties with various degree of self-renewal and differentiation potentials, and thereby held a merit in cell-based therapies for treating retinal degeneration diseases. In our laboratory, we use an enzymatic procedure to isolate, purify, and culture mouse Müller cells.

The role of netrin-1 in angiogenesis and diabetic retinopathy: a promising therapeutic strategy.

Netrin-1 is an axon guidance cue and is necessary for neural and vascular development. It is involved in regulating axon guidance for attraction or repulsion, and it has a dual function in endothelial tip cell migration during angiogenesis. Netrin-1 has been shown to play an important role in angiogenesis, cancer progression, and inflammatory disease. Here we review the role of netrin-1 in retinal and angiogenesis development and the associated signaling pathways in diabetic retinopathy. The currently available data suggest that netrin-1 is a promising target for the development of anti-angiogenesis drugs.

Application of CRISPR-Cas9 in eye disease.

The system of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated nuclease (Cas)9 is an effective instrument for revising the genome with great accuracy. This system has been widely employed to generate mutants in genomes from plants to human cells. Rapid improvements in Cas9 specificity in eukaryotic cells have opened great potential for the use of this technology as a therapeutic. Herein, we summarize the recent advancements of CRISPR-Cas9 use in research on human cells and animal models, and outline a basic and clinical pipeline for CRISPR-Cas9-based treatments of genetic eye diseases.

Applications of CRISPR/Cas9 in retinal degenerative diseases.

Gene therapy is a potentially effective treatment for retinal degenerative diseases. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system has been developed as a new genome-editing tool in ophthalmic studies. Recent advances in researches showed that CRISPR/Cas9 has been applied in generating animal models as well as gene therapy in vivo of retinitis pigmentosa (RP) and leber congenital amaurosis (LCA). It has also been shown as a potential attempt for clinic by combining with other technologies such as adeno-associated virus (AAV) and induced pluripotent stem cells (iPSCs). In this review, we highlight the main points of further prospect of using CRISPR/Cas9 in targeting retinal degeneration. We also emphasize the potential applications of this technique in treating retinal degenerative diseases.

Optimal Duration for the Use of 0.5% LevofloxacinEye Drops Before Vitreoretinal Surgery.

PURPOSE: To investigate various regimens of prophylactic antibiotic therapy for vitreoretinal surgery. DESIGN: This study compared different prophylactic therapies with 0.5% levofloxacin eye drops. METHODS: Two hundred nine patients from 7 hospitals scheduled to undergo vitreoretinal surgery were randomized into 3 groups to receive 0.5% levofloxacin eye drops for 1 day (6 times/d), 2 days (3 times/d), or 3 days (3 times/d) before surgery (groups 1D, 2D, and 3D, respectively). all patients received 3 applications of levofloxacin eye drops at 15-minute intervals beginning 1 hour before surgery and conjunctival sac disinfection with 5.0% povidone-iodine 15 minutes before surgery. conjunctival swabs were cultured before levofloxacin therapy (T0), on the morning of surgery (T1), after povidone-iodine disinfection (T2), immediately after surgery (T3), 1 day postoperatively (T4), and 1 week postoperatively (T5). RESULTS: The positive bacterial culture rates in groups 1D, 2D, and 3D fell, respectively, from 37.33%, 30.77%, and 31.88% at t0 to 10.67%, 12.31%, and 11.59% at t1 and 1.33%, 0%, and 0% at T2. at each time point (T0-T5), there were no significant differences among the groups in positive bacterial culture rate. the bacterial eradication rates in groups 1D, 2D, and 3D were, respectively, 100%, 94.74%, and 90.00% at T1 (after levofloxacin) and 100% in all groups at T2 (after povidone-iodine). CONCLUSIONS: The efficacy of levofloxacin in preventing postoperative infection was similar in the 3 treatment groups. it is recommended that 0.5% levofloxacin be used for only 1 day before vitreoretinal sur-gery (6 times/d) to minimize the use of prophylactic antibiotics.

Intravitreal infusion: A novel approach for intraocular drug delivery.

Intraocular injection has become an increasingly important intervention in the treatment of posterior segment diseases. However, an acute intraocular pressure (IOP) elevation after intravitreal injection is a common concern. This study aimed to evaluate the efficacy of intravitreal infusion in maintaining stable IOP in a rabbit model. Trypan blue (TB) 0.06% with an external pump was used to evaluate intravitreal infusion in rabbit eyes. Groups A (50 µL), B (100 µL), C (150 µL), and D (200 µL) were slowly infused over 30 minutes with TB. As a control, Group E underwent conventional intravitreal injection of 100 µL of TB. Group F received a bolus infusion of 100 µL of TB within 1 minute. The mean increases in IOP during infusion for each group were: Group A (7.93 ± 3.80 mmHg), B (13.97 ± 3.17 mmHg), C (19.91 ± 6.06 mmHg) and D (29.38 ± 8.97 mmHg). Immediately post-injection in group E the mean increase in IOP amounted to 34.33 ± 6.57 mmHg. The mean increase in IOP of group F after bolus infusion was 49.89 ± 1.71 mmHg. Intravitreal infusion maintains a stable IOP and provides a controlled infusion speed compared with intravitreal injection.