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Background and Objectives : Faricimab is a vascular endothelial growth factor A and angiopoietin-2 bispecific antibody. It is a novel therapeutic approach distinct from previous anti-vascular endothelial growth factor agents. This study aimed to evaluate the efficacy of switching from aflibercept to faricimab in the treatment of diabetic macular edema (DME) refractory to aflibercept, with a specific focus on the resolution of macular edema. Materials and Methods : The medical records of 29 eyes of 21 patients with DME that were refractory to intravitreal injections of aflibercept (IVAs) and who had completed the clinical follow-up of at least four intravitreal injections of faricimab (IVFs) were reviewed. The central retinal thickness (CRT), best-corrected visual acuity (BCVA), and the mean period (weeks) until the next injection were measured after the second-to-last IVA, first-to-last IVA, last IVA, and first to fourth IVFs following the transition to IVF. Results : The mean time from the first IVF to the assessment of effectiveness was significantly shorter than the time to the last IVA; however, no significant difference was found in the time from the second, third, and fourth IVFs to the assessment. The mean CRTs after the first and second IVFs were not significantly different from the CRT after the last IVA, but the mean CRT after the third and fourth IVFs was significantly thinner than that after the last IVA ( p = 0.0025 and p = 0.0076, respectively). The mean BCVAs after the third and fourth IVFs significantly improved compared with that after the last IVA ( p = 0.0050 and p = 0.0052, respectively). Conclusions : When switching the treatment to IVF for eyes with IVA-resistant DME, better treatment outcomes are achieved if IVF is performed three or more times.

Purpose: To assess the impact of intravitreal injections (IVTI) on ocular surface of patients treated with multiple injections., Methods: Prospective, tricentric study conducted in patients treated with unilateral IVTI. An asepsis protocol with povidone-iodine was used for all patients during IVTI. The primary endpoint was the difference between the pre-IVTI Ocular Surface Disease Index (OSDI 1) score and that measured on day one (D1) post-IVTI (OSDI 2). Secondary endpoints were the evaluation of predictive factors for OSDI scores, pain assessment on D1, and the Lacrydiag® analysis of tears from the injected eye versus contralateral eye before IVTI., Results: Two hundred and nineteen patients with a mean age of 75.9 ± 10 years were included. The mean OSDI2-OSDI1 difference was 19.2 ± 20.6 (p < 0.001). The mean noninvasive tear break-up time was 6.41 ± 4.59 seconds in the injected eye versus 7.36 ± 4.36 seconds in the contralateral eye (p < 0.001). In the multivariate analysis, the factors significantly associated with the OSDI 2 score were the OSDI 1 score (p < 0.001), the pain score on D1 (p < 0.001) the number of instilled glaucoma eye drop (p = 0.01) and a centre effect (centres 2 and 3 versus centre 1, p < 0.001)., Conclusion: Our results confirm the impairment of the ocular surface and quality of life immediately after an IVTI. These results suggest 3 levels of action to improve the immediate tolerance: improving the basal status of the ocular surface, reducing the contact time with povidone-iodine that might be toxic to the surface, and improving immediate post-IVTI treatment., (© 2021 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Injection of biological molecules into the intravitreous humor is of increasing interest for the treatment of posterior segment eye diseases such as age-related degenerative macular degeneration. The injection volume is limited by an increase in intraocular pressure (IOP) and 50-100 µL are typically used for most intravitreally (IVT) applied commercial products. Direct measurement of IOP is difficult and has not been studied dependent on solution properties and injection rates. We used an instrumental set-up to study IOP ex vivo using healthy enucleated porcine eyes. IOP was determined as a function of injection volume for viscosities between 1 and 100 mPas, injection rates of 0.1, 1, and 1.5 mL/min, and needle length and diameter (27/30G and 0.5/0.75″) using Dextran solutions. IOP increased exponentially for injection volumes larger than 100 µL. We did not observe differences in IOP dependent on viscosity, injection rate, and needle diameter. However, variability increased significantly for injection volumes larger than 100 µL and, unexpectedly, declined with higher viscosities. We demonstrate that the exponential increase in IOP is not reflected by injection force measurements for typical configurations that are used for IVT application. The present findings may guide injection volumes for intravitreal injection and inform injection force considerations during technical drug product development., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The Coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented disruption to the normal operation of the healthcare system. On a worldwide scale, hospitals suspended nonurgent surgeries and outpatient visits to downsize clinical loadings to redistribute manpower to counteract the pandemic's impact. So far, there is no evidence-based guideline defining a clear line between urgent and nonurgent indications of intravitreal injections (IVI). Herein, we aimed to summarize IVI algorithm modifications and discuss the patient prioritization according to medical needs in the hostile environment in the COVID crisis. Assessing current literature, we found that neovascular age-related macular degeneration is considered the utmost priority among conditions that require IVI. Other conditions assigned with a high priority include monocular or quasi-monocular patients (only one eye > 20/40), neovascular glaucoma, and new patients with significant vision loss. Although patients with central retinal vein occlusion and proliferative diabetic retinopathy are not advised to delay treatments, we found no consistent evidence that correlated with a worse outcome. Diabetic macular edema and branch retinal vein occlusion patients undertaking treatment delay should be regularly followed up every 2 to 3 months. Serving as the principle of management behind the algorithm modifications, the reduction of both patient visit and IVI therapy counts should be reckoned together with the risk of permanent visual loss and COVID infection., Competing Interests: Conflicts of interest: Dr. Shih-Hwa Chiou, an editorial board member at Journal of the Chinese Medical Association, had no role in the peer review process of or decision to publish this article. The other authors declare that they have no conflicts of interest related to the subject matter or materials discussed in this article., (Copyright © 2021, the Chinese Medical Association.)

To investigate the influence of age on the function and morphology of patients with myopic choroidal neovascularization (mCNV) and to evaluate the effect and prognostic factors of recurrence of Conbercept treatment on mCNV patients over 50 years. A total of 64 patients (64 eyes) with mCNV were enrolled in this retrospective study. The differences in baseline best-corrected visual acuity (BCVA) and morphological features on imaging between the younger group (˂ 50 years) and the older group (≥ 50 years) were analyzed. Of all, 21 eyes of 21 mCNV patients aged over 50 years who received Conbercept injection were further analyzed. Between the younger and the older group, significant differences were shown in mean BCVA (0.58 ± 0.28 vs 0.77 ± 0.31), subfoveal choroidal thickness (SFCT) (108.17 ± 78.32 μm vs 54.68 ± 39.03 μm) and frequency of vitreoretinal interface abnormalities (VIA) (2 vs 13), respectively (P < 0.05). After treated with Conbercept, the mean BCVA of 21 older mCNV patients increased from 0.83 ± 0.30 at baseline to 0.49 ± 0.24 at one year. Baseline BCVA, external limiting membrane damage, CNV area and CNV location correlated with the visual acuity at the 1-year follow-up. There were 7 (33.3%) recurrent cases during the follow-up and the risk of recurrence in patients with baseline central macular thickness (CMT) ≥ 262.86 μm was 14 times greater than that of patients with CMT < 262.86 μm. The risk of recurrence increased 1.84 times for every 100-μm increment in the CMT. Patients over 50 years with mCNV had a worse BCVA, thinner choroid, and higher risk of VIA than young mCNV patients. The standard Conbercept treatment strategy was safe and effective in mCNV patients over 50 years. As patients over 50 years with a greater CMT have a high risk of recurrence, more attention should be paid on these patients by following them up closely.

Intravitreal (IVT) administration of therapeutics is the standard of care for treatment of back-of-eye disorders. Although a common procedure performed by retinal specialists, IVT administration is associated with unique challenges related to drug product, device and the procedure, which may result in adverse events. Container closure configuration plays a crucial role in maintaining product stability, safety, and efficacy for the intended shelf-life. Careful design of primary container configuration is also important to accurately deliver small volumes (10-100 μL). Over- or under-dosing may lead to undesired adverse events or lack of efficacy resulting in unpredictable and variable clinical responses. IVT drug products have been traditionally presented in glass vials. However, pre-filled syringes offer a more convenient administration option by reducing the number of steps required for dose preparation there by potentially reducing the time demand on the healthcare providers. In addition to primary container selection, product development studies should focus on, among other things, primary container component characterization, material compatibility with the formulation, formulation stability, fill volume determination, extractables/leachables, and terminal sterilization. Ancillary components such as disposable syringes and needles must be carefully selected, and a detailed administration procedure that includes dosing instructions is required to ensure successful administration of the product. Despite significant efforts in improving the drug product and administration procedures, ocular safety concerns such as endophthalmitis, increased intraocular pressure, and presence of silicone floaters have been reported. A systematic review of available literature on container closure and devices for IVT administration can help guide successful product development.

Conbercept is a newly-developed anti-vascular endothelial growth factor (VEGF) drug. This study aimed to evaluate the effects of conbercept on inflammation and oxidative response in proliferative diabetic retinopathy (PDR). Morphology changes in retinal microvasculature of PDR patients were determined by optical coherence tomographic angiography (OCTA). The mice were injected with streptozocin (STZ) for 20 weeks to induced PDR, then the changes in inflammatory factors, oxidative response and histological analysis were examined with Elisa assay, real time-PCR and commercial kits analysis. Conbercept treatment significantly alleviated the retinal pathological changes and significantly reduced intercellular cell adhesion molecule-1 (ICAM-1), macrophage inflammatory protein-1 (MIP-1), IL-1β, IL-6 and TNF-α protein levels but not prostaglandin E1 (PGE1), prostaglandin E2 (PGE2) and prostaglandin F2a (PGF2a) levels, all of which were remarkably elevated in aqueous fluid of PDR patients compared with non-PDR subjects. Meanwhile the inhibitory effects of conbercept on these inflammatory factors were proved by RT-PCR assays in mice experiments. And the inflammatory signal such as p-IKBα and p-p65 was correspondingly inhibited by conbercept in STZ-treated mice. Conbercept treatment significantly elevated the aqueous glutathione level of PDR patients and inhibited NOX-1, NOX-4 and ph22phox mRNA expressions and ROS production of PDR mice. Ki67 immunofluorescence staining showed that conbercept inhibited endothelial cell proliferation in retina of PDR mice. In conclusion, conbercept significantly inhibited the angiogenesis, inflammation and oxidative response in PDR mice, and these findings further reveals the molecular mechanisms of conbercept in treating PDR., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Intravitreal injections have become the most commonly performed intraocular treatments worldwide. Because intravitreal injections may induce severe adverse events, such as infectious and noninfectious endophthalmitis, cataract, ocular hypertension, vitreous hemorrhage, or retinal detachment, appropriate awareness of the materials and techniques used are essential to reduce these sight-threatening complications. This review provides insights into the needles, syringes, silicone oil coating, sterilization methods, devices to assist intravitreal injections, scleral piercing techniques using needles, syringe handling, anesthesia, and safety issues related to materials and techniques. It is paramount that physicians be aware of every step involved in intravitreal injections and consider the roles and implications of all materials and techniques used. The ability to understand the theoretical and practical circumstances may definitely lead to state-of-the-art treatments delivered to patients. The most important practical recommendations are: choosing syringes with as little silicone oil as possible, or, preferably, none; avoiding agitation of syringes; awareness that most biologics (e.g., antiangiogenic proteins) are susceptible to changes in molecular properties under some conditions, such as agitation and temperature variation; understanding that improper materials and techniques may lead to complications after intravitreal injections, e.g., inflammation; and recognizing that some devices may contribute to an enhanced, safer, and faster intravitreal injection technique., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In current clinical settings, frequent intravitreal (IVT) injections of anti-vascular endothelial growth factors are used due to their short in-vivo half-life and rapid clearance from the back of the eye. The IVT injections are associated with pain, risk of infection, retinal detachment, and financial burden. Biologics molecules can undergo physical, chemical, and enzymatic degradation during formulation development and in the biological environment. Moreover, the complex ocular structures also act as a rate-limiting barrier for these biologics. Thus, delivering stable and clinically relevant biologics concentration to the back of the eye is still a challenge. Compare to other drug delivery platforms, injectable in-situ gelling depot systems (IISGDs) have emerged as an effective system for biologics delivery. In this review, we have discussed various biologics used in ocular therapeutics and their associated challenges. Different routes of delivery and associated tissue barriers are also discussed. Different types of IISGDs developed to date for biologics delivery to the back of the eye were also covered. To conclude, various critical parameters related to the formulation development process and injectable depot systems that need careful consideration and further investigations were highlighted.

Age-related macular degeneration (AMD) is the leading cause of blindness in older people in the developed world while Stargardt's disease (SD) is a juvenile macular degeneration and an orphan disease. Both diseases are untreatable and are marked by accumulation of lipofuscin advancing to progressive deterioration of the retinal pigment epithelium (RPE) and retina and subsequent vision loss till blindness. We discovered that a small molecule belonging to the tetrahydropyridoether class of compounds, soraprazan renamed remofuscin, is able to remove existing lipofuscin from the RPE. This study investigated the drug penetration, distribution, and elimination into the eyes of a mouse model for increased lipofuscinogenesis, following a single intravitreal injection. We measured the time course of concentrations of remofuscin in different eye tissues using high-performance liquid chromatography combined with mass spectroscopy (HPLC-MS). We also visualized the penetration and distribution of 3 H-remofuscin in eye sections up to 20 weeks post-injection using transmission electron microscopic (TEM) autoradiography. The distribution of silver grains revealed that remofuscin accumulated specifically in the RPE by binding to the RPE pigments (melanin, lipofuscin and melanolipofuscin) and that it was still detected after 20 weeks. Importantly, the melanosomes in choroidal melanocytes only rarely bind remofuscin emphasizing its potential to serve as an active ingredient in the RPE for the treatment of SD and dry AMD. In addition, our study highlights the importance of electron microscopic autoradiography as it is the only method able to show drug binding with a high intracellular resolution., (© 2020 The Authors. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)

Proliferative vitreoretinopathy (PVR) is a significant threat for vision recovery from retinal detachment or ocular trauma. Currently, no approved pharmacological intervention to prevent PVR. Daunorubicin (DNR) and dexamethasone (DEX) were sequentially loaded into oxidized porous silicon (pSiO 2 ) particles by covalent conjugation. The DNR + DEX-loaded particles, and control particles loaded with DNR only and DEX only were incubated with RPE-populated collagen for daily gel surface quantitation. Toxicity was monitored by ophthalmic examinations and histological evaluation 21 days after injection. At 3rd week following intravitreal injection, a localized retinal detachment (RD) was created by subretinal injection of Healon in all pretreated eyes in addition to 3 non-interventional control eyes. 10 µg of bromodeoxyuridine (BrdU) was injected into the vitreous 4 h before sacrifice on day 3 after RD induction. Retinal sections were stained for glial fibrillary green protein (GFAP) and BrdU to identify activated glial cells and retinal cell proliferation. The studies demonstrated that all three pSiO 2 particle types were well tolerated in vivo. DNR alone and DNR + DEX combination formulations demonstrated equally strong suppression on gel contraction (least square mean area of the gel: control = 1.71 vs. 30DNR = 1.85 or 30/40Dual = 1.83, p  < .05). Eyes pretreated with pSiO 2 -DNR + DEX exhibited the least GFAP activation (least square mean intensity mm -2 : Dual = 4.03, DNR = 7.76, Dex = 16.23, control = 29.11, p  < .05) and BrdU expression (Mean number of BrdU positive cells per mm of retina: Dual = 2.77, DNR = 4.58, Dex = 4.01, control = 6.16, p  < .05). The synergistic effect of a sustained release pSiO 2 -DNR/DEX showed promise for the prevention of PVR development while reducing the necessary therapeutic concentration of each drug.

Purpose: Patients increasingly use the internet to access health-related information to better understand their treatments. This study compares the quality, accountability, readability, accessibility, and presence of translation between private and academic online source material available to the public regarding intravitreal injections (IVIs)., Design: Cross-sectional analysis., Participants: Top 20 websites on a Google search for the terms eye injections, intravitreal injections, and anti-VEGF injections., Methods: Websites were classified as private or academic. Quality and accountability were assessed using the internationally recognized DISCERN criteria and the Health on the Net Code of Conduct (HONcode). Readability was evaluated using an online tool that provides a consensus readability grade. The presence of and languages available for translation were recorded., Main Outcome Measures: The primary outcome measure was a comparison of the DISCERN and HONcode quality and accountability scores between academic and private websites. Secondary outcome measures included evaluating readability, accessibility, and presence of translation (in particular, Spanish)., Results: Eleven academic and 9 private websites were included. The overall mean score using DISCERN criteria for the academic websites (3.11 ± 0.46) was significantly higher than that of private websites (2.23 ± 0.61; P < 0.007). Similarly, of a possible total of 14 points for the HONcode, the average quality score for academic websites (10.91 ± 2.66) was higher compared with that for private websites (6.44 ± 3.36; P < 0.009). The mean consensus reading grade level was similar between academic (11.73 ± 1.68) and private (11.78 ± 1.48) websites (P = 0.94). Spanish translation was offered by only 7 of the 20 websites (5 academic and 2 private websites)., Conclusions: The overall quality and accountability of online content for academic sites was significantly higher compared with that of private websites. Translation was rarely provided, and the readability grade level was significantly higher for both groups than recommended. Improving the quality, accountability, readability, and accessibility and incorporating translation in websites can help to improve patients' health literacy regarding IVIs, potentially leading to increased adherence to therapy plans and improved treatment outcomes., (Copyright © 2020 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: Patients with neovascular age-related macular degeneration (nARMD) will not deteriorate on visual acuity and retinal thickness when treated with bevacizumab injection frequencies of 6 or 8 weeks compared to 4 weeks. This study aimed to investigate this non-inferiority in quality of life (QoL). We hypothesized that less frequent bevacizumab injections are not inferior regarding patients reported QoL., Methods: Patients were randomized to bevacizumab every 4 (n = 64), 6 (n = 63), and 8 weeks (n = 64). Patients were at least 65 years old, have a best-corrected visual acuity of 20/200 to 20/20, no previous ARMD treatment and active leakage. Vision-related QoL questionnaire NEI VFQ-39 was used to assess QoL at baseline and after 1 year. General QoL questionnaire SF-36 was included for secondary analysis. Multilevel analyses were performed, correcting for age, gender and baseline., Results: The 6 (3.68; 95% CI - 0.63 to 8.00) and 8 (2.15; 95% CI - 2.26 to 6.56) weeks bevacizumab regimens resulted in non-inferior QoL differences compared to 4 weeks on the NEI VFQ-39. Also on the SF-36 the differences were well within the non-inferiority limits., Conclusion: Non-inferiority of the 6 and 8 weeks frequencies was demonstrated compared to 4 weeks on vision-related and general QoL in patients with nARMD. These results are in line with previously published results of lower frequency injections regarding visual acuity and central retinal thickness. Lower injection frequency may reduce burden, side effects, and treatment costs. In consideration of these results, 8 weeks frequency injections of intravitreal bevacizumab could be considered in patients with nARMD.

Intravitreal delivery can maximize the intensity of therapeutic agents and extend their residence time within ocular tissue. Melatonin is a lipophilic molecule that crosses freely biological barriers and cell membranes. This study intends to investigate the effects of intravitreally delivered melatonin on mouse retina. The visual function of administered mice is assessed by electrophysiological and behavior examinations three weeks after intravitreal delivery. Moreover, multi-electrode array (MEA) was used to assess the electrical activities of retinal ganglion cells (RGCs). We found that intravitreal delivery of high dosage melatonin (400-500 µg/kg) destroyed the retinal architecture and impaired the visual function of mice. Conversely, the melatonin administration at low dose (100-300 µg/kg) did not have any significant effects on the photoreceptor survival or visual function. As shown in the MEA recording, the photoreceptors activity of the central region was more severely disturbed by the high dose melatonin. A pronounced augment of the spontaneous firing frequency was recorded in these mice received high dosage melatonin, indicating that intravitreal delivery of high dosage melatonin would affect the electrical activity of RGCs. Immunostaining assay showed that the vitality of cone photoreceptor was impaired by high dose melatonin. These findings suggest that intravitreal melatonin is not always beneficial for ocular tissues, especially when it is administered at high dosage. These data add new perspectives to current knowledge about melatonin delivery at the ocular level. Further therapeutic strategies should take into consideration of these risks that caused by delivery approach.

Purpose: To investigate the changes in aqueous humor cytokine levels in response to short-term aflibercept therapy in treatment-naive patients with center-involving diabetic macular edema (DME). Methods: This is a prospective cohort study that included patients with treatment-naive DME with central subfield macular thickness ≥310 μm on optical coherence tomography from July 2015 to May 2017. Patients received 3 monthly intravitreal aflibercept injections. Aqueous samples for cytokine analysis were obtained before the first and third injections. Levels of various cytokines were measured using multiplex immunoassay. Main outcome measures were changes in aqueous cytokine levels from baseline to month 2. Results: A total of 17 patients were enrolled and 16 completed the study. The mean age was 57.2 ± 8.1 years. The following cytokines were significantly higher at month 2 versus baseline: transforming growth factor-beta (TGF-β)1 ( P  = 0.004), TGF-β2 ( P  = 0.017), inducible protein (IP)-10 ( P  = 0.011), and hepatocyte growth factor (HGF) ( P  = 0.02). There were significant reductions in the levels of vascular endothelial growth factor (VEGF) ( P  < 0.001), placental growth factor (PlGF) ( P  = 0.028), interleukin (IL)-6 ( P  = 0.011), and platelet-derived growth factor-AA (PDGF-AA) ( P  = 0.003). Conclusions: In treatment-naive patients with DME, short-term aflibercept therapy not only results in VEGF and PlGF suppression, but also leads to reduced levels of IL-6 and PDGF-AA and higher concentrations of TGF-β1, TGF-β2, HGF, and IP-10.

Purpose: To evaluate the periodicity of the intervals of lesion reactivation in patients with neovascular age-related macular degeneration (AMD). Methods: This retrospective study included 139 eyes diagnosed with treatment-naive neovascular AMD and treated with antivascular endothelial growth factor (VEGF) therapy. Patients were initially treated with 3 loading anti-VEGF injections using either ranibizumab or aflibercept. Additional treatment was administered only when lesion reactivation was noted. The difference between the time intervals to the first and the second reactivations was evaluated. The included eyes were divided into 2 groups according to the time interval to the first reactivation: the early reactivation group (≤6 months, n  = 86) and the late reactivation group (>6 months, n  = 53). The association between the time intervals to the first and the second reactivations was evaluated within each group. Results: The mean follow-up period was 52.7 ± 8.9 months. The first reactivation was noted at mean 9.4 ± 10.4 months after the loading injections. The second reactivation was noted at mean 6.2 ± 4.9 months after the treatment for the first reactivation. The time interval to the second reactivation was significantly shorter compared with the first reactivation ( P  = 0.018). The association between the time interval to the first and the second reactivations was significant only in the early reactivation group ( P  = 0.002). Conclusions: A short first reactivation interval suggests that there is a high likelihood that the second reactivation will also be short. However, a long first reactivation interval does not suggest that the second reactivation interval will be similarly long.

Purpose: Evaluation of product viscosity, density and aeration on the dose delivery and accuracy for intravitreal injections with commonly used commercially available hypodermic 1 mL syringes., Methods: Six commercially available hypodermic 1 mL syringes with different specifications were used for the study. Syringes were filled with the test solutions with different densities and viscosities. Syringes were also subjected to shaking stress to introduce aeration in the test solutions in the presence of different surfactant concentrations with and without high antibody concentration. Target intravitreal volumes of 100 μL, 50 μL and 30 μL were tested to assess dosing accuracy in a controlled simulated administration setup using DIN ISO 11040-4 guidelines and Zwick/Roell Z010 TN instrument., Results: With increasing product viscosity, higher volumes and hence doses were delivered especially for very low volumes like 50 μL and 30 μL. No impact of increasing product density was found on the delivered dose. The presence of surfactants or high protein concentration can lead to aeration, which also negatively affects the dose accuracy and precision., Conclusion: Formulation parameters like viscosity can have an impact on dose delivery using hypodermic syringes for intravitreal injections and on the resulting glide force.

Intravitreal injections are the standard procedure in the treatment of retinal pathologies, such as the administration of the anti-VEGF antibodies in age-related macular degeneration. The aim of this study is to evaluate the intraocular and blood pharmacokinetics after an intravitreal injection of 89 Zr-labelled bevacizumab and 89 Zr-labelled aflibercept in Sprague-Dawley rats using Positron Emission Tomography. First, both antibodies were radiolabelled to zirconium-89 with a maximum specific activity of 15 Mbq/mg for bevacizumab and 10 Mbq/mg for aflibercept. Four µL containing 1-1.2 Mq of 89 Zr-labelled compound were injected into the vitreous through a 35 G needle. A microPET acquisition was carried out immediately after the injection and at different time points through a 12-day study and blood samples were obtained through the tail vein. Radiolabelling was successfully performed with a radiochemical purity after ultrafiltration above 95% for both agents. Both antibodies ocular curves followed a two-compartment model in which an intraocular elimination half-life of 16.44 h was found for 89 Zr-bevacizumab and 4.51 h for 89 Zr-aflibercept, considering the alpha phase as the elimination phase. Regarding the beta phase, a half-life of 3.23 days for 89 Zr-bevacizumab and 4.69 days for 89 Zr-aflibercept were observed. With regards to blood concentration, 89 Zr-bevacizumab showed a blood half-life of 7.08 days, whereas 89 Zr-aflibercept's was 3.18 days, by a one-compartment model with first-order absorption kinetics. In conclusion, this study shows for the first time the ocular and blood pharmacokinetic analysis after intravitreal injection of aflibercept and bevacizumab in rats., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Opticin is an endogenous vitreous glycoprotein that may have therapeutic potential as it has been shown that supranormal concentrations suppress preretinal neovascularization. Herein we investigated the pharmacokinetics of opticin following intravitreal injection in rabbits. To measure simultaneously concentrations of human and rabbit opticin, a selected reaction monitoring mass spectrometry assay was developed. The mean concentration of endogenous rabbit opticin in 7 uninjected eyes was measured and found to be 19.2 nM or 0.62 μg/mL. When the vitreous was separated by centrifugation into a supernatant and collagen-containing pellet, 94% of the rabbit opticin was in the supernatant. Intravitreal injection of human opticin (40 μg) into both eyes of rabbits was followed by enucleation at 5, 24, and 72 h and 7, 14, and 28 days postinjection ( n = 6 at each time point) and measurement of vitreous human and rabbit opticin concentrations in the supernatant and collagen-containing pellet following centrifugation. The volume of distribution of human opticin was calculated to be 3.31 mL, and the vitreous half-life was 4.2 days. Assuming that rabbit and human opticin are cleared from rabbit vitreous at the same rate, opticin is secreted into the vitreous at a rate of 0.14 μg/day. We conclude that intravitreally injected opticin has a vitreous half-life that is similar to currently available antiangiogenic therapeutics. While opticin was first identified bound to vitreous collagen fibrils, here we demonstrate that >90% of endogenous opticin is not bound to collagen. Endogenous opticin is secreted by the nonpigmented ciliary epithelium into the rabbit vitreous at a remarkably high rate, and the turnover in vitreous is approximately 15% per day.

Comparison of a customized disposable kit with a conventional stainless steel instrument was performed for an intravitreal injection. A total of 2700 eyes of 2250 patients were enrolled in two groups. Comfort level of the patients was assessed using a 'Pain Scale' and any post intravitreal injection complications were examined clinically by a slit lamp biomicroscopy. Surgeon's ease was assessed by a questionnaire. In group A, no pain was recorded in 1231(82.06%) eyes, mild pain was d escribed in 184(12.27%), moderate pain was documented in 78 (5.2%) while, severe pain was noticed in 7(0.47%). In group B, no pain was seen in 1014(84.5%), mild pain was present in 123(10.25%), moderate pain was perceived in 58 (4.83%) while, severe pain was recorded in 5 (0.42%). With respect to surgeon's ease, 6 out of the 7 surgeons found the kit to be more convenient and cost effective as compared to the conventional instruments. Disposable intravitreal kit is beneficial for both the patients as well as the surgeons.

Antagonists of Vascular Endothelial Growth Factor (Anti-VEGF) are widely administered by intravitreal injection for the treatment of ocular pathologies such as Age-related Macular Degeneration, Diabetic Macular Edema, Proliferative Diabetic Retinopathy and occlusion of retinal vessels. Anti-VEGF agents, in particular bevacizumab, were introduced in oncology to inhibit tumor-induced angiogenesis feeding neoplastic tissues. Subsequently, other specific agents were developed for intraocular administration. Whereas systemic administration of anti-VEGF agents in oncology is burdened by increased risk of arterial hypertension and embolism, agents administered for ophthalmic indications are delivered locally into the eye globe in much smaller quantities. Nevertheless, clinical observations have raised the possibility that, even in these conditions, anti-VEGF agents may increase cardiovascular risk in patients who, being elderly and/or diabetic, are intrinsically prone to such events. This paper aims at reviewing the current knowledge on VEGF and its pharmacologic antagonists from mechanistic and side effect points of view, with specific reference to patients with sight-threatening conditions. Internists should be aware of the need to collaborate with ophthalmologists and pharmacovigilance operators to define as best as possible the risk/benefit balance of intravitreal agents in patients who might lose their sight if left untreated, or increase their risk of suffering a cardiovascular event if treated.

Therapeutic antibodies administered intravitreally are the current standard of care to treat retinal diseases. The ocular half-life ( t 1/2 ) is a key determinant of the duration of target suppression. To support the development of novel, longer-acting drugs, a reliable determination of t 1/2 is needed together with an improved understanding of the factors that influence it. A model-based meta-analysis was conducted in humans and nonclinical species (rat, rabbit, monkey, and pig) to determine consensus values for the ocular t 1/2 of IgG antibodies and Fab fragments. Results from multiple literature and in-house pharmacokinetic studies are presented within a mechanistic framework that assumes diffusion-controlled drug elimination from the vitreous. Our analysis shows, both theoretically and experimentally, that the ocular t 1/2 increases in direct proportion to the product of the hydrodynamic radius of the macromolecule (3.0 nm for Fab and 5.0 nm for IgG) and the square of the radius of the vitreous globe, which varies approximately 24-fold from the rat to the human. Interspecies differences in the proportionality factors are observed and discussed in mechanistic terms. In addition, mathematical formulae are presented that allow prediction of the ocular t 1/2 for molecules of interest. The utility of these formulae is successfully demonstrated in case studies of aflibercept, brolucizumab, and PEGylated Fabs, where the predicted ocular t 1/2 values are found to be in reasonable agreement with the experimental data available for these molecules.

Background/aims: To assess silicone oil (SO) release by different brands of syringes used for intravitreal injection under different handling conditions., Methods: Eight syringes were analysed: from the USA, Terumo 0.5 mL, Becton-Dickinson (BD) Tuberculin 1 mL, BD Luer-lok 1 mL, BD Ultra-Fine 0.3 mL and Exel Insulin 0.3 mL; from Germany, Braun Omnifix-F 1 mL and Braun Injekt-F 1 mL and from Spain, BD Plastipak 1 mL. The impact of air, priming the plunger, agitation by flicking and fluid temperature on SO release were assessed by light microscopy. Fourier transform infrared spectroscopy (FTIR) was performed to identify the molecular compound in each syringe., Results: Five hundred and sixty syringes were analysed. Terumo 0.5 mL and BD Ultra-Fine 0.3 mL released more SO than all others. BD Luer-lok 1 mL, BD Plastipak and Braun Omnifix-F 1 mL released little SO; BD Tuberculin 1 mL, Exel 0.3 mL and Braun Injekt-F 1 mL released the least SO. Priming the syringe and different temperatures did not significantly affect SO release. Agitation by flicking caused a significantly higher proportion of samples to have SO droplets and an increased number of oil droplets. Air had an additive effect on the release of oil in the agitation groups. FTIR identified polysiloxane in all syringes but Injekt-F., Conclusion: Syringes commonly used for intravitreal injections frequently release SO droplets, especially when agitated by flicking. To avoid unnecessary ocular risks, syringes should not be agitated before intravitreal injection. It is desirable that syringes be manufactured specifically for ophthalmic use., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: This study was conducted to evaluate the effects of anti-vascular endothelial growth factor (VEGF) antibody (bevacizumab) on vascular leakage and fibrosis in a monkey choroidal neovascularization (CNV) model. The relationship between fibrotic tissue and subretinal hyper-reflective material (SHRM), in optical coherence tomography (OCT) images, was also investigated., Methods: Experimental CNV was induced in male cynomolgus monkeys by laser photocoagulation. Intravitreal injection of bevacizumab at 0.5 mg/eye/dosing was initiated 2 weeks before or after laser irradiation and thereafter, conducted intermittently at 2- or 3-week intervals. Fluorescein fundus angiography (FA) and OCT imaging were conducted weekly from 2 to 7 weeks after laser irradiation. CNV leakage was evaluated by an established grading method using FA images. To assess the fibrosis and scarring, Masson's trichrome specimens of each CNV lesion were prepared, and morphometric analysis was conducted using an image analysis software., Results: The effects of bevacizumab on vascular leakage were shown using an established evaluation method. Morphometric analysis of Masson's trichrome-stained (MT) specimens revealed that collagen fiber synthesis was suppressed by bevacizumab pre-treatment (-29.2%) or post-treatment (-19.2%). SHRM was detected in OCT images in a monkey CNV model, and a significant correlation between the SHRM area in the OCT images and the collagen fiber area in the MT specimens was noted., Conclusion: In the established cynomolgus monkey CNV model, bevacizumab prevented blood leakage but could not completely suppress fibrosis. SHRM in the OCT images reflected retinal fibrous tissue in a laser-induced CNV monkey model. This model might be useful for elucidating the pathology and development therapy for neovascularization or fibrosis., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Administering anti-vascular endothelial growth factor (anti-VEGF) by intraocular injection has been shown to have a safe systemic profile. Nevertheless, incidents of acute kidney injury following anti-VEGF injection have been reported. We assessed the long-term effect of multiple intravitreal anti-VEGF injections on measures of renal function in patients with diabetes including rate of change of estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (ACR)., Methods: A retrospective review of patients receiving diabetic macular oedema (DMO) treatment was undertaken. Serum creatinine, ACR, number of intravitreal anti-VEGF injections and clinical characteristics were collected from electronic healthcare records (EHR). A co-efficient of eGFR and ACR change with time was calculated over a mean duration of 2.6 years. Regression modelling was used to assess variation in the number of anti-VEGF injections and change in eGFR and ACR., Results: The EHR of 85 patients with DMO (59% male, 78% type 2 diabetes mellitus [T2DM]) were reviewed. On average, 26.8 intravitreal anti-VEGF injections were given per patient over a mean duration of 31 months. No association between increasing number of anti-VEGF injections and rate of eGFR decline (beta = 0.04, 95% confidence intervals [CI]: - 0.02, 0.09; p = 0.22) or ACR change over time (beta = 0.02, CI: - 0.19, 0.23; p = 0.86) was detected, following adjustment for hypertension, cerebrovascular disease, T2DM, and medications taken., Conclusion: Our data suggests regular long-term intravitreal VEGF inhibition does not significantly alter the rate of change in eGFR and/or ACR with increasing number of treatment injections.

Conventional needle-based approaches in intravitreal drug delivery carry needle-stick-injury risk and could scare patients (belonephobia). Alternatively, our group has explored the application of an electromagnetic needleless injector in this paper. This work aims to improve intravitreal drug delivery, which in the future could assist physicians with automation and benefit patients by providing a needleless approach. Electromagnetic needleless intravitreal injections lack quantification studies. We investigate the delivery properties of the needleless injector where the characterization can be used to refine the design parameters of the prototype in subsequent iterations. Experiments were performed to characterize the injectant delivered from the electromagnetic needleless injector. Penetration tests were conducted to observe the influences of various injection barriers and tissues. Ultrasonic imaging modality was explored for future applications of the prototype. The dispersion of the injectant was controllable where injection depth and distribution is dependent on the input voltage. The synthetic barriers highlighted significant energy losses for penetration (maximum velocity falls from 4.46 to 1.57 mm/s with a 0.1-mm barrier). The biological barriers were difficult to penetrate with the current prototype. Our results indicate that the current electromagnetic injector offers controllable dispersion (depth and distribution) correlated with input voltages, which should have increased injection power for use with biological tissue. Ultrasonic imaging modality produced velocity profiles comparable to the optical approach which is promising for future in vivo studies. The influences of injection barriers should be further investigated in in vivo experiments with ultrasonic imaging modalities. Graphical abstract .

Posterior eye segment diseases are treated through monthly intravitreal injections, that evoke serious side effects. A promising approach to reduce injection frequency consists in producing biodegradable microspheres (MPs) releasing the protein in the vitreous body for long times. Moreover, a rational design of these MPs requires a discouraged diffusion/sedimentation within the intravitreal space, which are detrimental for the vision and the control over drug release kinetics. In this work, poly(lactic-co-glycolic acid) (PLGA)-based MPs encapsulating bovine serum albumin (BSA) were coated with hyaluronic acid (HA) at two molecular weights and tested for their release, diffusion and degradation features in simulated vitreous body (SVB). Results indicate that HA corona prolongs MP degradation time and BSA release. Furthermore, HA coating increased the affinity between MPs and SVB, thereby repressing device transport compared to control PLGA MPs. Results hold promise for the possible application of HA-decorated MPs for intravitreal injection of protein drugs., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: To investigate changes in axial length after intravitreal dexamethasone implantation in patients with macular edema., Methods: We performed a prospective comparative study of 46 patients with unilateral macular edema, due to diabetic retinopathy, retinal vein occlusion, and non-infectious uveitis, who underwent dexamethasone implantation. The fellow eyes of the patients were considered the control group. The central macular thickness was measured by spectral-domain optical coherence tomography, and axial length was measured by IOLMaster 700 optical coherence biometry. We compared axial length and central macular thickness values within the groups., Results: In the study group, the baseline central macular thickness was 460.19 ± 128.64 mm, significantly decreasing to 324.00 ± 79.84 mm after dexamethasone implantation (p=0.000). No significant change in central macular thickness measurements was seen in the control group (p=0.244). In the study group, the baseline axial length was 23.16 ± 0.68 mm, significantly increasing to 23.22 ± 0.65 mm after dexamethasone implantation (p=0.039). However, the control group exhibited no significant change in axial length (p=0.123)., Conclusions: In addition to significantly reducing central macular thickness measurements, intravitreal dexamethasone implantation also significantly changes optical biometry-based axial length measurements.

Currently, the two primary patient-derived xenograft (PDX) models of glioblastoma are established through intracranial or subcutaneous injection. In this study, a novel PDX model of glioblastoma was developed via intravitreal injection to facilitate tumor formation in a brain-mimicking microenvironment with improved visibility and fast development. Glioblastoma cells were prepared from the primary and recurrent tumor tissues of a 39-year-old female patient. To demonstrate the feasibility of intracranial tumor formation, U-87 MG and patient-derived glioblastoma cells were injected into the brain parenchyma of Balb/c nude mice. Unlike the U-87 MG cells, the patient-derived glioblastoma cells failed to form intracranial tumors until 6 weeks after tumor cell injection. In contrast, the patient-derived cells effectively formed intraocular tumors, progressing from plaques at 2 weeks to masses at 4 weeks after intravitreal injection. The in vivo tumors exhibited the same immunopositivity for human mitochondria, GFAP, vimentin, and nestin as the original tumors in the patient. Furthermore, cells isolated from the in vivo tumors also demonstrated morphology similar to that of their parental cells and immunopositivity for the same markers. Overall, a novel PDX model of glioblastoma was established via the intravitreal injection of tumor cells. This model will be an essential tool to investigate and develop novel therapeutic alternatives for the treatment of glioblastoma.

The present review focuses on recent clinical trials that analyze the efficacy of intravitreal therapeutic agents for the treatment of dry age-related macular degeneration (AMD), such as neuroprotective drugs, and complement inhibitors, also called immunomodulatory or anti-inflammatory agents. A systematic literature search was performed to identify randomized controlled trials published prior to January 2019. Patients affected by dry AMD treated with intravitreal therapeutic agents were included. Changes in the correct visual acuity and reduction in geographic atrophy progression were evaluated. Several new drugs have shown promising results, including those targeting the complement cascade and neuroprotective agents. The potential action of the two groups of drugs is to block complement cascade upregulation of immunomodulating agents, and to prevent the degeneration and apoptosis of ganglion cells for the neuroprotectors, respectively. Our analysis indicates that finding treatments for dry AMD will require continued collaboration among researchers to identify additional molecular targets and to fully interrogate the utility of pluripotent stem cells for personalized therapy.

Aims: To analyze contrast sensitivity of intravitreal bevacizumab injections with optimizing glycemic control versus optimizing glycemic control (in combination with sham injections) in eyes with Diabetic Macular Edema (DME)., Design: Prospective, interventional, masked, randomized controlled trial., Methods: Forty-one eyes of 34 patients with type 2 diabetes mellitus and DME with glycated hemoglobin (HbA1c) < 11% received either intravitreal bevacizumab injection (Group 1) or sham injection (Group 2) at 0 and 6 weeks along with optimizing glycemic control. Mean change in best-corrected visual acuity (BCVA), contrast sensitivity (CS), optical coherence tomography (OCT)-measured by central macular thickness (CMT) were compared and correlated at baseline, 2, 6 and 12 weeks., Results: The study showed a mean CS improved in group 1 from 1.14 ± 0.36 logCS to 1.32 ± 0.24 logCS and also in group 2 from 1.11 ± 0.29 logCS to 1.18 ± 0.29 logCS at 12 weeks (P = 0.12). CS and CMT promptly decreased in group 1 compared to group 2 at 2 weeks (ΔCS = 0.15 ± 0.25 vs. 0.03 ± 0.15 logCS; P = 0.04; ΔCMT = 116 ± 115 vs. 17 ± 71 μm; P = 0.01). There was a mean reduction of approximately 0.5% in HbA1c levels in both groups at 12 weeks (P = 0.002)., Conclusion: The use of bevacizumab in combination with optimizing glycemic control results in earlier improvement of contrast sensitivity in type 2 diabetes patients with DME. However, the optimizing glycemic control itself has shown also to be effective at 12 weeks. ClinicalTrials.gov Identifier: NCT02308644., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The intravitreal route faces many challenges in rapidly and effectively reaching posterior eye pathology, with administered therapeutics experiencing non-specific distribution around and premature clearance from ocular tissues. Nanobubbles and ultrasound may improve outcomes of intravitreally administered drugs by influencing the directionality of drug-containing particle migration. In this study, we assessed the impact of trans-scleral or corneal ultrasound application on the distribution of intravitreally-injected nanobubbles. Rhodamine-tagged gas entrapped nanobubble formulations were prepared and injected into ex vivo bovine and porcine eyes and subjected to ultrasound (1 MHz, 0-2.5 W/cm 2 , 50-100% duty, 60 s). Bovine eyes were partially dissected to visualize the vitreous humor and particle migration was evaluated via optical fluorescence spectroscopy. Directional migration in porcine eyes was evaluated using a snap freezing protocol complemented by quantification of regional fluorescence. The impact on nanobubble migration following pars-plana injection and sequential ultrasound cycle application from scleral or corneal-surface positions was also assessed. Administration of ultrasound significantly enhanced the directional migration of nanobubbles in both ex vivo models, with multiple corneal ultrasound cycles promoting greater migration of dye-filled nanobubbles to posterior regions of the vitreous. Moreover, particles moved in a directional manner away from the ultrasound wave source demonstrating an ability to effectively control the rate and path of nanobubble migration. These findings establish an encouraging new and safe modality enabling rapid distribution of intravitreally-injected therapeutics where expeditious therapeutic intervention is warranted., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background and Objectives: Ozurdex intravitreal injection is performed via a patented injection device. However, there is a common misconception among ophthalmologists regarding the relation between the speed of applicator button depression and the speed of pellet injection., Patients and Methods: Six dexamethasone intravitreal implants were injected into a calibrated ex vivo water bath. Three of the pellets were injected via rapid compression, whereas the other three implants were injected using a 3-second compression technique. The procedures were recorded using high-speed photography followed by calculation of pellet velocity and impact force., Results: The mean impact velocity and force of the pellet insertion is significantly higher in the fast injection group compared to the slow injection group., Conclusions: By depressing the Ozurdex implant injector during a 3-second time interval, the impact force of the implant pellet is reduced by about 95%. This new technique will theoretically reduce the risk of retinal injury and vitreous hemorrhage from Ozurdex injections. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e23-e25.]., (© 2019 Krambeer, Wannamaker, Tie, et al.)

Purpose: To compare effects of 5% topical povidone iodine with prophylactic topical azithromycin and moxifloxacin on bacterial flora in patients undergoing intravitreal injection., Methods: A total of 132 patients were randomly assigned to receive treatment with azithromycin or moxifloxacin, or no treatment (control group). In total, 528 specimens were obtained at the time of admission, 4 days before intravitreal injection, 4 days after intravitreal injection, and 8 days after intravitreal injection. Samples were immediately sent to the microbiology laboratory for incubation., Results: The microorganism observed most frequently was coagulasenegative Staphylococcus (23.8%). When the results of samples obtained on Day 4 before injection were assessed, growth of coagulase-negative Staphylococcus was significantly lower in the moxifloxacin group, compared with controls (p=0.049). Acinetobacter baumannii continued to grow after administration of azithromycin (p=0.033). When the results of four days after intravitreal injection were evaluated, growth of coagulase-ne gative Staphylococcus was higher in controls, compared with patients who received azithromycin or moxifloxacin (p=0.004). Eradication rate was significantly higher in the moxifloxacin group than in the control group (p=0.001). Samples obtained on Day 8 after intravitreal injection showed similar levels of bacterial growth in all groups (p=0.217)., Conclusion: Moxifloxacin was more effective than 5% povidone iodine in controlling the growth of conjunctival bacterial flora. Use of moxifloxacin in combination with 5% povidone iodine resulted in a synergistic effect.

Objective: N-methyl-D-aspartate (NMDA) excitotoxicity has been proposed to mediate apoptosis of retinal ganglion cells (RGCs) in glaucoma. Taurine (TAU) has been shown to have neuroprotective properties, thus we examined anti-apoptotic effect of TAU against retinal damage after NMDA exposure., Methodology: Sprague-Dawley rats were divided into 5 groups of 33 each. Group 1 was administered intravitreally with PBS and group 2 was similarly injected with NMDA (160 nmol). Groups 3, 4 and 5 were injected with TAU (320 nmol) 24 hours before (pre-treatment), in combination (co-treatment) and 24 hours after (post-treatment) NMDA exposure respectively. Seven days after injection, rats were sacrificed; eyes were enucleated, fixed and processed for morphometric analysis, TUNEL and caspase-3 staining. Optic nerve morphology assessment was done using toluidine blue staining. The estimation of BDNF, pro/anti-apoptotic factors (Bax/Bcl-2) and caspase-3 activity in retina was done using ELISA technique., Results: Severe degenerative changes were observed in retinae after intravitreal NMDA exposure. The retinal morphology in the TAU pre-treated group appeared more similar to the control retinae and demonstrated a higher number of nuclei than the NMDA group both per 100 μm length (by 1.5-fold, p < 0.001) and per 100 μm 2 area (by 1.41-fold, p < 0.05) of the GCL. After NMDA exposure, visible axonal swelling was observed in optic nerve sections. In comparison with the changes observed in the NMDA treated group, the TAU treated group showed fewer prominent changes; axonal swelling was less frequent and less marked. Additionally, no marked glial cell changes were observed in the TAU-pretreated group. All TAU treated groups, particularly the pre-treated group, showed a significant decrease in the NMDA-induced optic nerve damage, with a 50% reduction (p < 0.001) in the mean grading compared to NMDA group. For the same, there was 25% decrease in co- and post-treatment groups, as compared with the NMDA group. Pre-treatment with TAU abolished apoptotic response to NMDA as indicated by decrease in the number of TUNEL- and caspase-3-positive cells. TAU pre-treatment also increased the Bcl-2 level (by 2.80-fold, p < 0.001) and decreased the level of Bax (by 34%, p < 0.01), and activity of caspase-3 (by 36%, p < 0.001) compared to NMDA group., In Conclusion: our study revealed that pre-treatment with TAU prevents NMDA-induced retinal cell apoptosis more effectively than co- and post-treatment with TAU., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: To evaluate the possible effects of multiple intravitreal anti-vascular endothelial growth factor (VEGF) injections on intraocular pressure (IOP)., Methods: This study included 50 eyes of 50 patients who underwent multiple (≥ 10 injections) intravitreal anti-VEGF injections in one eye with age-related macular degeneration, diabetic macular edema or retinal vein occlusion. IOP was recorded after every injection on the first postoperative day. IOP > 21 mmHg was regarded as abnormal. For statistical analysis, the IOP was correlated with the number of injections., Results: A total of 669 IOP-measurements (mean 13.4 treatment/eye) were analyzed. No IOP-elevation was recorded in 43 eyes (86%). Transient elevated IOP > 21 mmHg was measured after 19 intravitreal injections (2.8%, one patients with 8 IOP elevations). In general, there was no increasing risk of IOP elevation with time, no case of sustained IOP elevation and no additional long term glaucoma treatment necessary. Eyes with pre-existing glaucoma were significantly more affected from transient IOP-elevation than non-glaucoma eyes (5.5 vs. 2.2%)., Conclusions: Multiple anti-VEGF injections are not associated with an increased risk of sustained IOP-elevation. On the other hand, individual risk factors exist and predispose to IOP-elevation (e.g., pre-existing glaucoma)., Competing Interests: Die Autoren geben an, dass kein Interessenkonflikt besteht., (Georg Thieme Verlag KG Stuttgart · New York.)

The goal of this report is to provide a review on different strategies for the use of pro re nata (PRN) and treat and extend (T&E) regimens with intravitreal anti-VEGF agents (bevacizumab, ranibizumab or aflibercept) in patients with retinal diseases such as neovascular AMD, diabetic macular oedema and macular oedema due to retinal vein occlusion. The main focus is to present the effectiveness and visual outcomes of both PRN and T&E regimens in the main pivotal trials and studies based on currently available evidence. We also discuss the advantages and disadvantages of both regimens, as well as monitoring and treatment of the disease, including treatment intervals and injection frequency. Currently there is increasing interest in establishing a regimen which offers the best visual outcome with lower injection frequency, and with reduced treatment burden by individualising treatment intervals and minimising the number of clinic visits and costs. Studies have shown that the PRN regimens in a clinical setting are insufficient in assuring the best visual outcome. The PRN regime requires frequent clinic visits to monitor disease status and intravitreal treatment if needed in a reactive approach. Individualised T&E regimens can improve visual outcome and require fewer injections than those administered in a monthly regimen and fewer monitoring visits than those in a PRN regimen., Competing Interests: Nein., (Georg Thieme Verlag KG Stuttgart · New York.)

Aim: We aimed to investigate the effectivity of the 0.0625 mg dose of bevacizumab in patients with retinopathy of prematurity (ROP) and compare the results with 0.625 mg dose of intravitreal bevacizumab (IVB) injection., Methods: The medical records of the patients with type 1 ROP who received IVB monotherapy were retrospectively reviewed. Demographic and clinical characteristics of the patients were recorded. The patients were classified into two groups with respect to received dose of bevacizumab as follows: group F (n = 46) (full dose of bevacizumab-0.625 mg/0.025 ml) and group L (n = 45) (low dose (one tenth) of bevacizumab-0.0625 mg/0.025 ml)., Results: Both treatment dose regimens have similar outcomes. Moreover, the mean retinal vascularization time seemed to be significantly higher in group F compared to group L, 168 ± 65 and 97 ± 29 days, respectively (p < 0.001). Disappearance of plus sign is observed earlier in group F (2.45 ± 1.7 vs 3.66 ± 2.46 days, respectively, p = 0.03)., Conclusions: The low dose (0.0625 mg) of IVB treatment was effective as full (0.625 mg) dose in ROP treatment. Moreover, our results showed that low-dose treatment might provide faster retinal vascularization than the regular used dose. On the other hand, disappearance of the plus sign takes longer time in patients treated with low dose compared to eyes treated with full dose of IVB that should be taken into account.

This study was aimed at investigating the role of IVI angle on the induced stresses and deformations among the components of the eye. Thereafter, the most optimal angle of IVI to minimize the complications of post IVI at the injection site on a basis of the computed stresses via a Fluid-Structure Interaction (FSI) computational model was proposed. IntraVitreal Injection (IVI) is broadly employed as a principal treatment of vascular vitro-retinal diseases. So far, there have been reports regarding the complications of post IVI and determine them as severe uveitis, tractional retinal detachment, IntraOcular Pressure (IOP) elevation as well as ocular haemorrhage. However, there is a lack of knowledge on how to reduce the subsequent ocular tissue damage and patient symptoms in the injection site. Seven different IVI angles were simulated, including 0∘, 15∘, 30∘, 45∘, 60∘, 75∘, and 90∘, through the Finite Element (FE) code; and the term, 'post IVI complication' or 'injury', in the results was interpreted as the level of maximal principal stress in the eye components. The results revealed the lowest amount of stresses at the angle of 45∘ in respect to the horizontal line (acute to the surface of the sclera) for the lens, iris, vitreous body, aqueous body, ciliary body, sclera, retina, and choroid. The cornea illustrated the same amount of stress at the angles of 45∘, 60∘, 75∘, and 90∘ with the highest one at the IVI angle of 30∘. The lowest and the highest stresses among the eye components regardless of IVI angle were observed in the choroid and retina/sclera, respectively, which imply the importance of the IVI angle on the stresses of these eye components. The findings of the contemporary research revealed that the IVI angle of 45∘ would trigger less post IVI complications and, as a result, a more effective surgery outcome compared to the other angles, i.e., 0∘, 15∘, 30∘, 60∘, 75∘, and 90∘.

Gene therapy in ophthalmology has developed rapidly, and there has been a breakthrough in the treatment of Leber's hereditary optic neuropathy. After receiving an intravitreal injection of rAAV2-ND4, patients followed up over a certain time period showed a definite increase in visual acuity. Visual acuity testing is critical for assessing the efficacy of rAAV2-ND4 intravitreal injection.

The burden of intravitreal injections has increased tremendously over the past few years. Since traditionally the operation theatre setup is currently used for this procedure, it is increasingly becoming difficult to manage such a patient load in the theatres. To overcome this challenge, office-based setup for intravitreal injection was started. This study was planned to determine the incidence of endophthalmitis after office-based intravitreal bevacizumab injection and to compare it with previously reported incidence of endophthalmitis after operation theatre-based intravitreal injections. The study was conducted at Al-Ehsan Eye Hospital, Lahore, Pakistan, from July 2015 to June 2016, and comprised patients who received intravitreal injections of bevacizumab (Avastin) for different ocular indications. A total of 1,047 intravitreal injections were given in an office-based set-up. Of them, 2(0.19%) cases of clinically suspected endophthalmitis were identified. Office-based set-up for intravitreal bevacizumab injection was found to have comparable safety profile with traditional operation theatre-based set-up.