Evolution of Intravitreal Therapy for Retinal Diseases-From CMV to CNV: The LXXIV Edward Jackson Memorial Lecture

Reducing rates of endophthalmitis from intravitreal injections - strategies and areas of controversy

PURPOSE OF REVIEW

Post-injection endophthalmitis (PIE) is the most concerning complication that accompanies intravitreal injections. This review discusses the recent literature in endophthalmitis prophylaxis including types of antisepsis, the use of topical antibiotics, methods of anesthesia, masking, and office-based versus operating room-based injections.

RECENT FINDINGS

Povidone iodine (PI) remains the gold standard for PIE prophylaxis. Chlorhexidine gluconate (CHG) is an alternative antiseptic agent utilized in other areas of medicine with similar broad spectrum antibacterial activity. Recent clinical trials have demonstrated that the rate of endophthalmitis is similar with CHG prophylaxis compared to PI prophylaxis while offering improved patient comfort at a similar cost. Routine use of topical antibiotics should be avoided as they do not appear to reduce endophthalmitis risk and may promote bacterial resistance. All methods of anesthesia appear to be acceptable. In-office injections are not associated with an increased rate of endophthalmitis compared to operating room injections.

SUMMARY

The rate of post-injection endophthalmitis is extremely low due to a myriad of measures employed by retina specialists. Topical antisepsis is the most important tool to combat post-injection endophthalmitis. CHG is emerging as an alternative to PI due to its efficacy and enhanced patient comfort.

Intravitreal therapy-success stories and challenges

Intravitreal injections have revolutionized the treatment of various sight-threatening diseases of the posterior segment of the eye. Initially explored for treatment of bacterial endophthalmitis, intravitreal injections rapidly expanded to combat retinal vascular disease in particular. Especially anti-vascular endothelial growth factor agents have emerged as a cornerstone of intravitreal therapy, targeting neovascular age-related macular degeneration and diabetic macular edema as important examples. Advances continue, with novel therapies such as complement inhibitors now available as treatment for geographic atrophy secondary to non-neovascular age-related macular degeneration, offering hope for a previously untreatable condition. Pioneering approaches such as the port delivery system and intravitreal gene therapy aim to improve treatment efficacy while minimizing patient burden. Despite notable successes, challenges for intravitreal therapies persist, including ocular and systemic complications and high treatment burden. Future research endeavors aim to address these challenges and enhance treatment outcomes. This comprehensive review critically evaluates the efficacy, safety, and cost-effectiveness of intravitreal injections, delving into emerging trends and future directions.

Comparison of Renal Adverse Events Between Intravitreal Anti-Vascular Endothelial Growth Factor Agents: A Meta-Analysis

PURPOSE

To compare the risk of renal adverse events, particularly acute kidney injury (AKI), between intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents.

DESIGN

Meta-analysis.

METHODS

A systematic literature search was conducted on Ovid Medline, Embase, and the Cochrane Library for randomized controlled trials (RCTs) published from January 2005 to February 2024 involving adult patients receiving anti-VEGF intravitreal injections for age-related macular degeneration, diabetic macular edema, and macular edema secondary to retinal vein occlusion. The primary outcome was the comparative risk of AKI between anti-VEGF agents and sham injections. Secondary outcomes involved other renal adverse events. Subgroup analyses were conducted by specific disease indications. A random-effects model was used for meta-analysis to estimate risk ratios (RRs) and their 95% confidence intervals, with a P value of <.05 representing statistical significance. Risk of bias was assessed using the Cochrane Risk of Bias 2 (ROB2) tool, and the certainty of evidence was evaluated through the Cochrane Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework.

RESULTS

A total of 10,031 eyes from 11 RCTs were included. No significant differences were found in the risk of acute or chronic renal conditions, obstructive uropathies, neoplasia, or infectious processes between anti-VEGF agents and sham therapy. AKI was reported in 5.4% (n = 10/185) of patients treated with bevacizumab, 1.3% (n = 6/456) with sham, 1.0% (n = 48/4724) with aflibercept, 0.8% (n = 15/1929) with faricimab, 0.5% (n = 5/1098) with brolucizumab, and 0.3% (n = 5/1639) with ranibizumab. No significant differences in AKI risk were observed between any of the anti-VEGF agents and sham (P > .05 for all comparisons). However, there was an increased risk of patient-reported symptoms with 1.25 mg bevacizumab compared to 2 mg aflibercept (RR = 3.26, 95% CI = 1.07-9.93, P = .04), driven primarily by reports of hematuria: 4.3% (bevacizumab), 0.7% (sham), 0.2% (aflibercept), 0.1% (faricimab), and 0.1% (ranibizumab).

CONCLUSIONS

US Food and Drug Administration (FDA)-approved intravitreal anti-VEGF agents do not significantly increase the risk of AKI compared to sham injections. Nevertheless, variations in patient-reported renal symptoms were observed across different anti-VEGF drugs. These variations were influenced primarily by differences in hematuria events, which may be a result of differential systemic absorption by these agents. These results underscore the importance of continuous monitoring and pharmacovigilance.

Toward a greener vision: A review on advancing sustainability in ophthalmology

The growing environmental impact from healthcare sector necessitates the adoption of sustainable strategies to reuse, recycle, reduce waste, lower carbon emissions, etc. In ophthalmology, surgical waste poses a significant environmental challenge, particularly due to the high volume of surgeries, along with single-use instruments, packaging materials and disposable surgical supplies. Examples of practical strategies to reduce surgical waste include adopting reusable surgical instruments when safe and feasible, minimizing unnecessary packaging and optimizing operating room protocols, e.g., multidose topical drops on multiple patients. An education regarding sustainability for medical personnel can further decrease waste production in the long term. Collaboration between healthcare providers, manufacturers and policymakers is essential to developing and integrating sustainability into ophthalmic practice. By implementing these strategies, ophthalmologists can contribute to a more environmentally responsible healthcare system without compromising patient safety.

Chlorhexidine for ocular antisepsis before intravitreal injection: A systematic review and meta-analysis

Povidone-iodine (PI) is the gold standard for pre-intravitreal injection ocular antisepsis. Chlorhexidine (CHX) is an emerging alternative with less ocular irritation. This meta-analysis aims to evaluate post-injection endophthalmitis rates with the use of CHX compared to PI. A systematic search of PubMed, Embase, and Scopus was performed for studies published between January 1, 2000 and February 21, 2024. Data on the number of injections and endophthalmitis cases were analyzed. A sample-size weighted mean difference (MD) meta-analysis was performed using RevMan 5.4.1, p < 0.05 was considered statistically significant. Five studies including 230,656 injections were pooled to determine an endophthalmitis rate of 0.0003 [95 % CI, 0.0001-0.0005] with preinjection CHX antisepsis. Three studies included an additional PI branch and thus were used for secondary meta-analysis comparing CHX against PI. The analysis consisted of 185,799 injections in the CHX group and 269,441 injections in the PI group. No significant difference in the weighted relative risk of endophthalmitis with CHX was found (RR = 1.27 [95 %CI 0.50-3.22], p = 0.62). A total of 24 and 31 cases of culture-positivity were recorded in the CHX and PI groups respectively but no significant difference in weighted means was found (RR = 1.42[95 %CI 0.96-2.12], p = 0.08). This meta-analysis disclosed that the rate of post-IVI endophthalmitis while using CHX antisepsis is approximately 1 in 3937 injections, compared to 1 in 3906 with PI. CHX was not associated with a significant difference in the rate of endophthalmitis or culture-positivity compared to PI.

Evidence-based guidelines for drug dosing in intravitreal injections in silicone oil-filled eyes: Pharmacokinetics, safety, and optimal dosage

We evaluate the pharmacokinetics, safety, and optimal dosages of intravitreal agents in silicone oil (SO)-filled eyes, addressing challenges in administering such therapies. We assessed the pharmacological properties and safety profiles of intravitreal drugs in SO-filled eyes, deriving conclusions and guidance from available literature and expert consensus. Preclinical data suggest comparable half-lives of anti-vascular endothelial growth factoragents in SO-filled eyes, but clinical evidence is mainly from case reports and small series. Available research prioritizes standard dosages, particularly for bevacizumab (1.25 mg), supported by stronger evidence than aflibercept (2 mg) or ranibizumab (0.5 mg). Intravitreal steroids, especially dexamethasone at 0.7 mg, show efficacy and safety, while evidence for fluocinolone acetonide at 0.19 mg is limited. Intravitreal methotrexate has been reported at the dosage of 250-400 μg, with keratitis as the primary expected side effect. Case reports indicate tolerability of standard dosages of antivirals (foscarnet 1.2-2.4 mg/0.1 mL, ganciclovir 4 mg/0.1 mL) and the antibiotic combination piperacillin/tazobactam (250 μg/0.1 mL). We offer guidance based on current, but limited, literature. Standard dosage of intravitreal agents should be carefully considered, along with close monitoring for potential side effects, which should be discussed with patients.

So Many Injections, So Much Waste: Understanding the Environmental Impact of Intravitreal Injections

Purpose: To understand the environmental burden associated with intravitreal injections (IVIs) and propose actionable solutions to mitigate this impact. Methods: An analysis of current IVI practices was conducted, focusing on packaging waste, energy consumption, the carbon footprint, and disposal processes. Data on the environmental footprint of IVIs were collected from the literature and industry reports. Sustainable practices were evaluated for their feasibility and impact on reducing waste and emissions. Industry efforts to address these environmental concerns were also surveyed. Results: This study found that the packaging of IVI medications, especially brand-name drugs, generates considerable waste. In addition, transportation and storage of these medications substantially contribute to carbon emissions. Implementing take-back programs, reducing packaging size, and using reusable or biodegradable coolers could significantly decrease waste. Adopting multidose packaging and streamlining injection practices can reduce both waste and costs. Sustainable practices have the potential for considerable environmental and economic benefits without compromising patient care. Conclusions: Addressing the environmental burden of IVIs requires a multifaceted approach involving many different parties. Collaboration among retina specialists, industry partners, and stakeholders is essential to foster sustainable practices, reduce waste, and minimize carbon emissions. This effort will ensure that our commitment to patient care matches our commitment to environmental stewardship.

Clinical Use of Home OCT Data to Manage Neovascular Age-Related Macular Degeneration

Purpose: To investigate how home optical coherence tomography (OCT) influences the clinical decision-making of retina specialists for the management of neovascular age-related macular degeneration (nAMD). Methods: In this retrospective imaging review, 15 retina specialists each evaluated 10 home OCT data segments from 29 eyes being treated for nAMD. Based on OCT data, indications were identified for when eyes should be treated, which antivascular endothelial growth factor should be used, and the specific retinal fluid and time thresholds for notification. Results: Withholding treatment was recommended in 64 (42.7%) of 150 data segments (95% CI, 34.7-50.6), whereas 100% of eyes received treatment on the last day of each data segment. Treatment was recommended in 86 cases (57.3%), with treatment occurring 7 or more days before the actual treatment was advised in 52 (60.5%) of 86 data segments. This earlier treatment would have prevented the accumulation of intraretinal fluid (IRF), subretinal fluid (SRF), and total retinal fluid for 69.1 nL, 162.2 nL, and 231.2 nL days. Retina specialists chose a different type of treatment agent in 35 (40%) of 86 cases. The following notification values were set: IRF, mean 9.8 ± 14.9 nL (median, 5; IQR, 5); SRF, mean 10.2 ± 16.1 nL (median, 5.5; IQR, 5); total retinal fluid, mean 15.2 ± 24.0 nL (median, 10; IQR, 5). The time-based notification interval was set at a mean of 34.7 ± 21.9 days (median, 30; IQR, 2). Conclusions: Home OCT-based decision-making by retina specialists differed substantially from actual clinical care. Home OCT has the potential to facilitate personalized care in nAMD.

Comprehensive Pharmacokinetic Evaluation of High Melanin Binder Levofloxacin in Rabbits Shows Potential of Topical Eye Drops for Posterior Segment Treatment

Purpose

The purpose of this work was to understand the impact of melanin binding on ocular pharmacokinetics after administration of a high-binder model drug via different administration routes.

Methods

We applied levofloxacin to pigmented and albino rabbits as eye drops (single and multiple), as well as by intravitreal and intravenous injections. Ocular tissues and plasma were analyzed for levofloxacin concentrations with liquid chromatography-mass spectrometry (LC-MS/MS), and pharmacokinetic parameters were calculated.

Results

The data show enrichment of levofloxacin and weeks-long retention in pigmented tissues. Upon intravitreal injection, the area under the curve (AUC) values in pigmented tissues were about 9 to 15 times higher than the respective values in the albino rabbits, but this difference expanded to 255- to 951-fold following topical eye drop administration. Multiple dosing of eye drops led to substantial accumulation of levofloxacin in the pigmented tissues: AUC values were 3 to 12 times higher than after intravitreal injection. The AUCs were much lower after single topical or intravenous drug administrations. High drug levels (0.1-35 µM) were always observed in the neural retinas of pigmented eyes; the highest exposure was seen after intravitreal administration followed by multiple doses of topical drops. Single topical instillation and intravenous injections to the albino rabbits resulted in vitreal bioavailability values of 0.009% and 0.003%, respectively.

Conclusions

Melanin binding can be used to achieve targeted drug delivery and extended retention in pigmented ocular tissues. The results from topical multiple dosing experiments suggest that eye drop treatment may yield drug exposures and responses comparable to intravitreal delivery, even in the retinal pigment epithelium and choroid.

Doxorubicin-loaded DNA origami nanostructures: stability in vitreous and their uptake and toxicity in ocular cells

Biocompatibility and precise control over their size and shape make DNA origami nanostructures (DONs) promising for drug delivery applications. Whilst many investigations have focused on cancer treatment, this might not be the best fit for DONs that get degraded by nucleases in blood. In comparison, an eye is a uniquely isolated target organ, which could benefit from DONs to achieve and maintain therapeutic concentrations in diseases that threaten the eyesight of millions of patients every year. We investigated the loading of doxorubicin (DOX) as a model drug into three distinct DONs and tested their stability upon storage. Further, we chose one structure (24HB) to probe its stability under physiological conditions in cell media and porcine vitreous, before examining the uptake and effect of DOX-loaded 24HB (24HB-DOX) on the cell viability in a retinal cell line (ARPE-19). Similar to previous reports, the tested low μM loading concentrations of DOX resulted in high drug loadings of up to 34% (m/m), and remained mostly intact in water for at least 2 months at 4 °C. In cell media and porcine vitreous at 37 °C, however, 24HB required additional Mg2+ supplementation to avoid degradation and the loss of the attached fluorophores. With added Mg2+, 24HB remained stable in vitreous for 7 days at 37 °C. The treatment with 24HB-DOX was well tolerated by ARPE-19 cells, compared to the observed higher toxicity of free DOX. Uptake studies revealed, however, that in contrast to free DOX, very little 24HB-DOX was taken up by the cells. Instead, the particles were observed to attach around the cells. Hence, our results suggest that since the uptake seems to be the bottleneck for therapies using DONs, further strategies such as adding ocular targeting moieties are necessary to increase the uptake and efficacy of doxorubicin-loaded DONs.

Intravitreal Antibiotics versus Early Vitrectomy Plus Intravitreal Antibiotics for Postinjection Endophthalmitis: An IRIS® (Intelligent Research in Sight Registry) Analysis

PURPOSE

To determine if intravitreal injection of antibiotics alone versus early pars plana vitrectomy (PPV) plus injection of intravitreal antibiotics predicted better or worse visual outcomes for patients with endophthalmitis after anti-VEGF injections.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients developing endophthalmitis after receiving an intravitreal anti-VEGF injection from the American Academy of Ophthalmology IRIS® (Intelligent Research in Sight) Registry between 2016 and 2020.

METHODS

Inclusion criteria were endophthalmitis diagnosis within 1 to 28 days after anti-VEGF injection and a recorded visual acuity (VA) at baseline, on the day of diagnosis, and posttreatment. Patients in the Injection Only group underwent intravitreal injection of antibiotics alone and in the Early Vitrectomy group received PPV with intravitreal antibiotics or intravitreal injection followed by PPV within 2 days of diagnosis. Patients were excluded if they had cataract surgery during the study, intravitreal steroids before endophthalmitis, or intermediate/posterior uveitis or cystoid macular edema. The study created a 1:1 matched cohort using Mahalanobis distance matching, accounting for the differences in VA at baseline and diagnosis.

MAIN OUTCOME MEASURES

Posttreatment logarithm of the minimum angle of resolution (logMAR) VA.

RESULTS

A total of 1044 patients diagnosed with postinjection endophthalmitis met the inclusion and exclusion criteria. In the unmatched cohort, there were 935 patients in the Injection Only and 109 in the Early Vitrectomy group. In 1:1 matched cohort, 218 patients (109 in each group) were included; the median logMAR VAs were 0.32 (20/40-20/50) at baseline, 0.88 (∼20/150) at diagnosis, and 0.57 (20/70-20/80) posttreatment. There were no statistically significant differences in the visual outcomes between the 2 matched treatment groups (b = 0.05; P = 0.23); including the subgroup of patients with VA worse than 1.0 logMAR (b = 0.05; P = 0.452).

CONCLUSIONS

There was no significant difference in final VA outcomes between patients receiving Injection Only and those treated with Early Vitrectomy for postinjection endophthalmitis. The findings support the use of either treatment strategy.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Similar Risk of Kidney Failure among Patients with Blinding Diseases Who Receive Ranibizumab, Aflibercept, and Bevacizumab: An Observational Health Data Sciences and Informatics Network Study

PURPOSE

To characterize the incidence of kidney failure associated with intravitreal anti-VEGF exposure; and compare the risk of kidney failure in patients treated with ranibizumab, aflibercept, or bevacizumab.

DESIGN

Retrospective cohort study across 12 databases in the Observational Health Data Sciences and Informatics (OHDSI) network.

SUBJECTS

Subjects aged ≥ 18 years with ≥ 3 monthly intravitreal anti-VEGF medications for a blinding disease (diabetic retinopathy, diabetic macular edema, exudative age-related macular degeneration, or retinal vein occlusion).

METHODS

The standardized incidence proportions and rates of kidney failure while on treatment with anti-VEGF were calculated. For each comparison (e.g., aflibercept versus ranibizumab), patients from each group were matched 1:1 using propensity scores. Cox proportional hazards models were used to estimate the risk of kidney failure while on treatment. A random effects meta-analysis was performed to combine each database's hazard ratio (HR) estimate into a single network-wide estimate.

MAIN OUTCOME MEASURES

Incidence of kidney failure while on anti-VEGF treatment, and time from cohort entry to kidney failure.

RESULTS

Of the 6.1 million patients with blinding diseases, 37 189 who received ranibizumab, 39 447 aflibercept, and 163 611 bevacizumab were included; the total treatment exposure time was 161 724 person-years. The average standardized incidence proportion of kidney failure was 678 per 100 000 persons (range, 0-2389), and incidence rate 742 per 100 000 person-years (range, 0-2661). The meta-analysis HR of kidney failure comparing aflibercept with ranibizumab was 1.01 (95% confidence interval [CI], 0.70-1.47; P = 0.45), ranibizumab with bevacizumab 0.95 (95% CI, 0.68-1.32; P = 0.62), and aflibercept with bevacizumab 0.95 (95% CI, 0.65-1.39; P = 0.60).

CONCLUSIONS

There was no substantially different relative risk of kidney failure between those who received ranibizumab, bevacizumab, or aflibercept. Practicing ophthalmologists and nephrologists should be aware of the risk of kidney failure among patients receiving intravitreal anti-VEGF medications and that there is little empirical evidence to preferentially choose among the specific intravitreal anti-VEGF agents.

FINANCIAL DISCLOSURES

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Calculated Drug Concentrations in Currently Available Intravitreal Therapies: Determination of Dilution Factor and Deviation From Recommended Doses

In ophthalmology, intravitreal therapies are currently not personalized/customized and are not adjusted to the individual vitreous volume. With reference to the recently published calculation formula for a more accurate estimation of the vitreous body, we determined the dose of intravitreal medication for different vitreous volumes and compared them with the average volume. Using the axial length of the eye, the formula for the vitreous volume exact (VIVEX) can provide a more accurate indication of the vitreous volume in individual cases than an assumed standard volume of 4 mL. The concentration of active substances in small eyes may be twice as high as that in normal-sized emmetropic eyes. In contrast, large eyes may show less than half of the recommended drug concentration. The calculated concentrations of the investigated intravitreal drugs in small and large eyeballs showed impressive differences with large deviations from the recommended doses. Further systematic studies should follow to find out whether this has any impact on the effectiveness or side effects of the injected drugs.

Risk of Endophthalmitis Based on Cumulative Number of Anti-VEGF Intravitreal Injections

PURPOSE

To determine the risk of endophthalmitis in eyes undergoing intravitreal injections (IVIs) of anti-VEGF based on cumulative number of injections per eye.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients from a single center undergoing IVIs of ranibizumab, aflibercept, or bevacizumab.

METHODS

Eyes were divided into quartiles based on injection number causative of endophthalmitis between January 1, 2011, and June 1, 2022.

MAIN OUTCOME MEASURES

Interquartile clinical outcomes and cumulative risk of endophthalmitis per injection and per eye.

RESULTS

A total of 43 393 eyes received 652 421 anti-VEGF injections resulting in 231 endophthalmitis cases (0.035% per injection, 1 in 2857), of which 215 were included. The cumulative endophthalmitis risk increased from 0.0018% (1 in 55 556) after 1 injection to 0.013% (1 in 7692) after 11 injections (0.0012 percentage point change), versus 0.014% (1 in 7143) after 12 injections to 0.025% (1 in 4000) after 35 injections (0.00049 percentage point change), versus 0.025% (1 in 4000) after 36 injections to 0.031% (1 in 3226) after 66 injections (0.00017 percentage point change), versus 0.031% (1 in 3226) after 63 injections to 0.033% (1 in 3030) after 126 injections (0.000042 percentage point change) (P < 0.001). Likewise, the cumulative endophthalmitis risk per eye increased from 0.028% (1 in 3571) to 0.20% (1 in 500) between injections 1 and 11 (0.018 percentage point change), versus 0.21% (1 in 476) to 0.38% (1 in 263) between injections 12 and 35 (0.0075 percentage point change), versus 0.38% (1 in 263) to 0.46% (1 in 217) between injections 36 and 66 (0.0026 percentage point change), versus 0.46% (1 in 217) to 0.50% (1 in 200) between injections 67 and 126 (0.00063 percentage point change) (P < 0.001).

CONCLUSIONS

The cumulative endophthalmitis risk per injection and per eye increased with greater number of injections received but appeared to do so at a higher rate during earlier injections and at a lower rate further into the treatment course.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Treatment patterns and visual acuity change of AMD patients, before, during and after the COVID-19 pandemic lockdowns: A large cohort

PURPOSE

To evaluate the impact of the changes in treatment patterns before, during and after the COVID-19 pandemic on best-corrected visual acuity (BCVA) in previously treated neovascular age-related macular degeneration (nAMD) patients.

METHODS

A multi-centre, retrospective, observational study of consecutive nAMD patients during 2019-2021. Data collected included demographics, BCVA, dates of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections and clinic visits.

RESULTS

A total of 1652 eyes of 1652 nAMD patients were included, out of which 850 eyes were assessed in 2019 (pre-COVID-19), 630 eyes were assessed in 2020 (COVID-19) and 974 eyes were assessed in 2021 (post-COVID-19). During the COVID-19 period, the mean number of anti-VEGF injections was significantly lower than the corresponding pre-COVID-19 and post-COVID-19 periods (5.55 compared to 6.13 and 6.60, respectively p < 0.01). A constant lower ratio of injections per patient/month was observed during COVID-19 compared to previous and following years, with a notable decline during March-April, reaching a ratio of 0.4 in 2020 versus 0.65 in 2019 and 0.62 in 2021 (p < 0.01). Baseline BCVA (0.825, p < 0.001), number of injections (-0.007, p < 0.001), gender (-0.027, p = 0.037) and age (0.004, p < 0.001) were shown to be significant predictors of final BCVA.

CONCLUSION

During the COVID-19 period, patients were treated with significantly less intravitreal anti-VEGF injection compared to the previous year with compensation in the following year. These changes in treatment patterns did not have a significant impact on BCVA outcomes. Age, gender, baseline BCVA and number of injections are predictors of final visual outcomes.

Tracing the barriers to decarbonising ophthalmology: A review

As climate change demands increasingly urgent mitigation of greenhouse gas emissions, the health sector needs to do its part to decarbonise. Ophthalmologists share concerns about climate change and seek opportunities to reduce their environmental impact. When measuring the footprint of ophthalmology, major contributions are from patient travel to clinics, and from the large amounts of single-use disposable materials that are consumed during surgeries and sterile procedures. Ophthalmic services in India have already demonstrated systems that consume far fewer of these products through efficient throughput of patients and the safe reuse of many items, while maintaining equivalent safety and quality outcomes. Choosing these low-cost low-emission options would seem obvious, but many ophthalmologists experience barriers that prevent them operating as Indian surgeons do. Understanding these barriers to change is a crucial step in the decarbonisation of ophthalmology and the health sector more broadly.

Recent Progress of Solid Lipid Nanoparticles and Nanostructured Lipid Carriers as Ocular Drug Delivery Platforms

Sufficient ocular bioavailability is often considered a challenge by the researchers, due to the complex structure of the eye and its protective physiological mechanisms. In addition, the low viscosity of the eye drops and the resulting short ocular residence time further contribute to the observed low drug concentration at the target site. Therefore, various drug delivery platforms are being developed to enhance ocular bioavailability, provide controlled and sustained drug release, reduce the number of applications, and maximize therapy outcomes. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) exhibit all these benefits, in addition to being biocompatible, biodegradable, and susceptible to sterilization and scale-up. Furthermore, their successive surface modification contributes to prolonged ocular residence time (by adding cationic compounds), enhanced penetration, and improved performance. The review highlights the salient characteristics of SLNs and NLCs concerning ocular drug delivery, and updates the research progress in this area.

Quantifying burden of intravitreal injections: questionnaire assessment of life impact of treatment by intravitreal injections (QUALITII)

AIM

To quantify the areas of burden experienced by patients requiring repeated intravitreal injections (IVI) in the management of exudative retinal diseases.

METHODS

The validated Questionnaire to Assess Life Impact of Treatment by Intravitreal Injections survey was administered to patients at four retina clinical practices across four US states. The primary outcome measure was Treatment Burden Score (TBS), a single score assessing overall burden.

RESULTS

Of 1416 (n=657 age-related macular degeneration; n=360 diabetic macular oedema/diabetic retinopathy; n=221 retinal vein occlusion; n=178 other/uncertain) patients, 55% were women with an average age of 70 years. Patients most frequently reported receiving IVI every 4-5 weeks (40%). The mean TBS was 16.1±9.2 (range 1-48; scale of 1-54), and the TBS was higher in patients with diabetic macular oedema and/or diabetic retinopathy (DMO/DR) (17.1) compared with those with age-related macular degeneration (15.5) or retinal venous occlusive (15.3) (p=0.028). Though the mean level of discomfort was quite low (1.86) (scale 0-6), 50% of patients reported experiencing side effects more than half of the visits. Patients having received fewer than 5 IVI reported higher mean anxiety levels before (p=0.026), during (p=0.050) and after (p=0.016) treatment compared with patients having received more than 50 IVI. After the procedure, 42% of patients reported restrictions from usual activities due to discomfort. Patients reported a high mean satisfaction rating of 5.46 (scale 0-6) with the care of their diseases.

CONCLUSIONS

The mean TBS was moderate and highest among patients with DMO/DR. Patients with more total injections reported lower levels of discomfort and anxiety but higher disruption to daily life. Despite the challenges related to IVI, the overall satisfaction with treatment remained high.

A hypothetical therapeutic effect of light peripheral panretinal photocoagulation in neovascular age-related macular degeneration

Background

Vascular endothelial growth factor (VEGF) is a significant modulator of ocular angiogenesis, including that of neovascular age-related macular degeneration (nAMD). Intravitreal injection of anti-VEGF is the benchmark treatment for most retinal vascular diseases, including nAMD, diabetic maculopathy, and macular edema secondary to retinal venous occlusion. Anti-VEGF treatment is a high-frequency, time-consuming, non-cost-effective therapy, especially in countries and regions with limited resources. This treatment is easily restricted, and in practice, maintaining long-term periodic care is challenging for patients.

Hypothesis

Light peripheral panretinal photocoagulation (PPRP) is applied in a mild form (barely visible mild light gray mark) anterior to the equator so as not to jeopardize the visual field. PPRP lessens the ischemia that causes neovascularization and decreases the metabolic demand in the peripheral retina. PPRP reduces serum angiopoietin-2 and VEGF levels in patients with type 2 diabetes mellitus with proliferative diabetic retinopathy. We propose using light PPRP to suppress VEGF secretion, aiming to attenuate the VEGF drive and halt choroidal neovascular growth in eyes with nAMD. Our regimen is based on two concepts: first, nAMD is a diffuse or generalized disease that affects the posterior segment; and second, PPRP is very effective in regressing diabetic retinopathy. PPRP has reportedly been successful in cases of macular edema (diabetic or following venous occlusion) resistant to VEGF antagonists. Light PPRP may be used as prophylaxis, adjunctive treatment, or monotherapy in nAMD when intravitreal injections of VEGF antagonists are not feasible.

Conclusions

The established light PPRP therapy could be promising as a one-time, cost-effective therapy or prophylaxis in patients with nAMD or at high risk. This proposed modality could be suitable for patients who have injection phobia or prefer a one-time affordable therapy to the long-term monthly visits to retinologists. Future trials are necessary to verify the safety and efficacy of this proposed treatment modality in selected patients with nAMD.

Cardiovascular and Mortality Risk with Intravitreal Vascular Endothelial Growth Factor Inhibitors in Patients with Diabetic Retinopathy

OBJECTIVE

To investigate the cardiovascular (CV) safety associated with intravitreal anti-VEGF injections (IAVIs) in patients with diabetic retinopathy (DR).

DESIGN

Population-based cohort study using Medicare and 2 commercial insurance claims databases in the United States from January 2009 to December 2017.

SUBJECTS

Patients with DR aged ≥ 18 years in whom treatment with either IVAIs or laser procedure or intravitreal steroid injections was initiated.

METHODS

We estimated the propensity score (PS) using multivariable logistic regression models, including 85 baseline covariates and PS-matched patients in a 1:1 ratio. We estimated the pooled hazard ratios (HRs) and 95% confidence intervals (CIs). Subgroup analyses based on prior history of CV events were also conducted.

MAIN OUTCOME MEASURES

A composite CV outcome of myocardial infarction (MI) or stroke, its individual components, and all-cause mortality in 180 and 365 days after treatment initiation.

RESULTS

We identified 61 508 PS-matched patients in a 1:1 ratio in whom either IVAIs or laser or steroid treatment was initiated. Compared with laser or steroid treatment, IAVIs were not associated with an increased risk of the composite CV outcome (HR, 0.95; 95% CI, 0.83-1.09), MI (HR, 0.93; 95% CI, 0.76-1.13), or stroke (HR, 0.98; 95% CI, 0.80-1.19) or the risk of all-cause mortality (HR, 1.25; 95% CI, 0.97-1.62) at 180 days of follow-up. At 365 days, the risk of the composite CV outcome, stroke, and MI remained similar between the 2 groups, although the risk of all-cause mortality was increased with IAVIs (HR, 1.35; 95% CI, 1.14-1.60). The subgroup analysis showed that the risk of all-cause mortality was increased in patients with a prior history of CV events.

CONCLUSIONS

Among > 60 000 patients with DR, those who received IAVIs had a risk of CV events similar to those who received laser or steroid treatment. However, the risk of all-cause mortality was higher in patients who received IAVIs for DR.

Pharmacokinetics of Sirolimus in a Novel Liposome Delivery System in Selected Ocular Tissues and Plasma Following a Single Subconjunctival Injection in Dutch Belted Rabbits

Purpose: To determine the pharmacokinetics of a proprietary liposomal sirolimus (LS) formulation in ocular tissues and plasma following a single subconjunctival (SCJ) injection in Dutch belted rabbits (DBR). Analytical methods for detection of LS in plasma, aqueous humor (AH), vitreous humor (VH), retina, combined retina/choroid/retinal pigment epithelium, sclera, and iris/ciliary body were developed to examine samples. Methods: Thirty male DBR were subconjunctivally injected in both eyes with 0.1 mL of LS of 1,000 μg/mL. At selected times post-injection, ocular tissues and whole blood samples were obtained. Sirolimus concentrations were measured using liquid chromatography/tandem mass spectrometry. Results: No LS was detected in serum or AH at any time. All other examined ocular tissues had quantifiable amounts of LS at all times. LS levels were highest in sclera and lowest in VH, suggesting LS followed the supraciliary and suprachoroidal spaces to reach the posterior segment. Vitreous peak of sirolimus levels occurred at 2 h, and the sclera adjacent to the injection peaked at both 2 and 96 h. LS levels in remaining ocular tissues peaked at 6 h and decreased with time, persisting at presumed therapeutic levels on day 22. Conclusions: LS can quickly diffuse into posterior intraocular tissues after SCJ injection without reaching quantifiable levels in AH or serum in DBR. Peak levels occurred in posterior intraocular tissues at 6 h and persisted in all tissues after 3 weeks. SCJ LS in DBR is safe, has a stable pharmacokinetic profile, and should be considered for further study in human trials for autoimmune ophthalmopathies.

Impact of Delayed Intravitreal Anti-Vascular Endothelial Growth Factor (VEGF) Therapy Due to the Coronavirus Disease Pandemic on the Prognosis of Patients with Neovascular Age-Related Macular Degeneration

This study estimated the outcome of delayed intravitreal anti-vascular endothelial growth factor (VEGF) therapy due to the coronavirus (COVID-19) disease pandemic on the prognosis of patients with neovascular age-related macular degeneration (nAMD). This study retrospectively enrolled 57 nAMD patients whose intravitreal anti-VEGF injections were delayed for >2 weeks between February and June 2020. Best-corrected visual acuity (BCVA), central subfield thickness (CST), and anatomical characteristics were evaluated before (baseline), on the day, and at 2, 4, and 6 months after the delayed injection, and risk factors were identified. The average injection interval before and after treatment delay was 3.05 ± 1.45 and 2.41 ± 1.46 months, respectively (p = 0.002). The CST at baseline and on the day of delayed injection was 227.82 ± 62.46 and 267.26 ± 77.74 µm, respectively (p < 0.001). The average BCVA decreased from 0.29 ± 0.29 logMAR (baseline) to 0.38 ± 0.31 logMAR (6 months) (p = 0.001). The maximum subretinal fluid (SRF) height increased from 84.32 ± 89.33 µm (baseline) to 121.38 ± 103.36 µm (6 months) (p = 0.027). A higher baseline maximum SRF height was associated with less SRF height deterioration 6 months later (p < 0.001). Delayed intravitreal anti-VEGF therapy caused by the COVID-19 pandemic has worsened BCVA and residual SRF in nAMD patients after a temporary recovery. The baseline SRF reduce the degree of SRF height deterioration.

COVID-19 Pandemic Lockdowns Impact on Visual Acuity of Neovascular AMD Patients: A Large cohort

PURPOSE

Evaluating the impact of delayed care, secondary to COVID-19 pandemic lockdowns, on visual acuity in previously treated neovascular AMD (nAMD) patients.

METHODS

A multi-center, retrospective, study of nAMD patients previously treated with anti-VEGF injections who were followed-up during 2019 (pre COVID-19) and compared to nAMD patients during 2020 (COVID-19).

RESULTS

A total of 1,192 nAMD patients with a mean age of 81.5 years met the inclusion criteria. Of these, 850 patients were assessed in 2019 (pre COVID-19) and 630 patients assessed in 2020 (COVID-19). 308 patients were assessed through both 2019-2020 and thus were included in both cohorts. There was no significant difference between the years 2020 and 2019 in terms of baseline and change in BCVA (p=0.342, p=0.911 respectively). Mean number of anti-VEGF injections was significantly lower (5.55 Vs 6.13, p<0.01), with constant lower ratio of injections per patient in the COVID-19 period. Baseline BCVA (0.859, p<0.01), number of injections (-0.006, p=0.01) and age (0.003, p<0.01) were predictors of final BCVA.

CONCLUSIONS

In nAMD patients, delayed care secondary to COVID-19 pandemic lockdowns has no statistically significant impact on BCVA. Baseline BCVA, older age and lower number of yearly anti VEGF injections are predictors for decrease BCVA.

In vivo antimicrobial activity of 0.6% povidone-iodine eye drops in patients undergoing intravitreal injections: a prospective study

To investigate the antimicrobial activity of a preservative-free 0.6% povidone-iodine eye drop as an antiseptic procedure in decreasing the conjunctival bacterial load in eyes scheduled for intravitreal treatment and to compare its efficacy to the untreated fellow eye used as the control group. Prospective cohort analysis in which 208 patients received preservative-free 0.6% povidone-iodine eye drops three times a day for three days before intravitreal injection. Before and after the prophylactic treatment, a conjunctival swab was collected from both the study eye and the untreated contralateral eye, used as control. The swab was inoculated on different culture media and the colony-forming units were counted. Bacteria and fungi were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Treatment with 0.6% povidone-iodine eye drops significantly reduced the conjunctival bacterial load from baseline (p < 0.001 for blood agar and p < 0.001 for chocolate agar) with an eradication rate of 80%. The most commonly isolated pathogen at each time-point and in both groups was coagulase-negative Staphylococci, isolated in 84% of the positive cultures. The study provides evidence about the effectiveness of 0.6% povidone-iodine eye drops treatment in reducing the conjunctival bacterial load in eyes scheduled for intravitreal treatment.

Risk of Death Associated With Intravitreal Anti-Vascular Endothelial Growth Factor Therapy: A Systematic Review and Meta-analysis

Importance

Although intravitreal anti-vascular endothelial growth factor (VEGF) treatment represents the first-line therapy for many retinal diseases, the issue of their systemic safety is debatable.

Objectives

To assess whether intravitreal anti-VEGF therapy might be associated with increased risk of mortality and which variables are associated with the increase.

Data Sources

PubMed, MEDLINE, and Embase databases, the Cochrane Library, and ClinicalTrials.gov were systematically searched from inception to May 6, 2019.

Study Selection

Randomized clinical trials comparing intravitreal anti-VEGF treatment with control groups and with follow-up of at least 6 months were selected.

Data Extraction and Synthesis

Data were independently collected by 2 investigators. Meta-analyses were conducted using the frequentist and Bayesian methods. For the frequentist approach, random- and fixed-effects models were used, with random-effects models considered the primary technique. Odds ratios (ORs) with 95% CIs were computed. For the bayesian approach, uninformative and informative priors were used. Odds ratios with 95% credible intervals (CrIs) were computed. Meta-regression analyses were based on random-effects models.

Main Outcomes and Measures

The primary outcome measure was the all-cause death rate. Secondary outcomes included meta-regression analyses on the following variables: type of drug, number of injections, follow-up time, diagnosis, and cardiovascular risk.

Results

Of 2336 studies identified, 34 unique studies with 8887 unique participants were included in the present meta-analysis. For the frequentist analysis, fixed- and random-effects models yielded similar estimates (ORs, 1.34 [95% CI, 0.95-2.07; P = .09] and 1.34 [95% CI, 0.89-2.01; P = .17], respectively). For the Bayesian approach, noninformative and informative priors yielded similar results (ORs, 1.34 [95% CrI, 0.79-2.34; 0.13 probability of OR≤1.00] and 1.40 [95% CrI, 0.82-2.32; 0.11 probability of OR≤1.00], respectively). Meta-regression analyses showed the following risk for 1 injection more: frequentist OR of 1.12 (95% CI, 1.04-1.22; P = .005) and Bayesian OR of 1.06 (95% CrI, 0.98-1.15; 0.06 probability of OR≤1.00).

Conclusions and Relevance

In this study, no difference was found in the mortality rate between intravitreal anti-VEGF treatment and control groups. Additional data seem warranted to determine whether the mortality rate is increased in patients receiving a greater number of injections.

Questionnaire to Assess Life Impact of Treatment by Intravitreal Injections (QUALITII): Development of a patient-reported measure to assess treatment burden of repeat intravitreal injections

Objective

To understand patient burden of treatment of repeated intravitreal injections (IVI) in the management of exudative retinal diseases.

Methods and analysis

Participants were sampled from a large urban retina specialty practice in Houston, Texas, USA, based on history of ongoing receipt of IVI. The 50-item Questionnaire to Assess Life Impact of Treatment by Intravitreal Injections questionnaire was developed to evaluate the patient experience including discomfort, anxiety, inconvenience and satisfaction. Categorial principal components analysis (CATPCA) was performed to assess construct validity and internal consistency. A subset of these items was used to establish a measure of total treatment burden, referred to as the IVI Treatment Burden Score (TBS).

Results

142 patients participated in this study. CATPCA analysis revealed five dimensions of patient burden: disruption of normal routine or capacity, anxiety, frequency of visits, chronicity of disease and perceived treatment value or satisfaction. Together, these dimensions accounted for 67% of variance explained. Cronbach's alpha was 0.97. The most frequently cited cause of discomfort was the feeling after anaesthetic wore off. The most common source of anxiety was fear of injection and associated discomfort or pain. Regarding inconvenience, patients reported temporary postinjection debilitation, requiring an average of 8 hours for recovery per treatment. The most frequently identified sources of satisfaction were confidence in the provider or treatment and interactions with staff.

Conclusions

Understanding and quantifying the patient burden associated with repeated IVI for exudative retinal diseases can reveal opportunities to improve delivery methods. The TBS could serve to inform strategies to maximise treatment adherence and optimise patient experiences.

The COVID-19 Pandemic Has Had Negative Effects on Baseline Clinical Presentation and Outcomes of Patients with Newly Diagnosed Treatment-Naïve Exudative AMD

PURPOSE

To investigate whether the coronavirus disease 2019 (COVID-19) pandemic-associated postponement in care had effects on the baseline clinical presentation of patients with newly diagnosed treatment-naïve exudative neovascular age-related macular degeneration (AMD).

METHODS

We included the first 50 consecutive patients referred within the COVID-19 pandemic with a diagnosis of treatment-naïve exudative neovascular AMD. Two groups of fifty consecutive patients with newly diagnosed neovascular exudative AMD presenting in 2018 and 2019 (control periods) were also included for comparisons.

RESULTS

Baseline visual acuity was statistically worse in patients referred during the COVID-19 pandemic period (0.87 ± 0.51 logarithm of the minimum angle of resolution (LogMAR)) as compared with both the "2019" (0.67 ± 0.48 LogMAR, p = 0.001) and "2018" (0.69 ± 0.54 LogMAR, p = 0.012) control periods. Data on the visual function after a loading dose of anti-vascular endothelial growth factor (VEGF) was available in a subset of patients (43 subjects in 2020, 45 in 2019 and 46 in 2018, respectively). Mean ± SD best corrected visual acuity (BCVA) at the 1-month follow-up visit after the third anti-VEGF injection was still worse in patients referred during the COVID-19 pandemic (0.82 ± 0.66 LogMAR) as compared with both the "2019" (0.60 ± 0.45 LogMAR, p = 0.021) and "2018" (0.55 ± 0.53 LogMAR, p = 0.001) control periods. On structural optical coherence tomography (OCT), the maximum subretinal hyperreflective material (SHRM) height and width were significantly greater in the COVID-19 pandemic patients.

CONCLUSIONS

We demonstrated that patients with newly diagnosed treatment-naïve exudative neovascular AMD referred during the COVID-19 pandemic had worse clinical characteristics at presentation and short-term visual outcomes.

ANTIVASCULAR ENDOTHELIAL GROWTH FACTOR DOSING AND EXPECTED ACUITY OUTCOME AT 1 YEAR

PURPOSE

To determine the dose-response characteristics of the antivascular endothelial growth factor agents ranibizumab and aflibercept in neovascular age-related macular degeneration using published randomized trials and observational series.

METHODS

Literature review of published series from 2006 to 2018 as determined from electronic searches of PubMed and the Cochrane Library. Data extracted included treatment strategy, frequency, and first year visual acuity response. Monthly or bimonthly treatment schedules were classified as Fixed, pro re nata studies as PRN, treat and extend as TE, and when no strategy was listed, as Variable.

RESULTS

Of 2062 citations retrieved, 96 were deemed eligible; these 96 citations provided 120 data points of dose frequency versus visual acuity change in Year 1 of treatment. The dose-response curve was nonlinear, but a log transform of the number of injections per year yielded a linear relationship defined by the expression, Letters of Improvement = -6.66 + 15.7*log (number of injections Year 1). After accounting for the number of injections neither the drug used (ranibizumab or aflibercept) nor the strategy used (Fixed, pro re nata, treat and extend, or Variable) were significant predictors of acuity change. As a group, studies using the pro re nata approach had the lowest number of injections and the worst acuity improvements as a treatment strategy.

CONCLUSION

There seems to be a predictable, mathematically defined relationship between dose frequency and visual acuity change at 1 year in neovascular age-related macular degeneration. The performance of current treatment efforts, as suggested by reported series and Medicare claims data, seems to be substandard.

Lightweight Learning-Based Automatic Segmentation of Subretinal Blebs on Microscope-Integrated Optical Coherence Tomography Images

PURPOSE

Subretinal injections of therapeutics are commonly used to treat ocular diseases. Accurate dosing of therapeutics at target locations is crucial but difficult to achieve using subretinal injections due to leakage, and there is no method available to measure the volume of therapeutics successfully administered to the subretinal location during surgery. Here, we introduce the first automatic method for quantifying the volume of subretinal blebs, using porcine eyes injected with Ringer's lactate solution as samples.

DESIGN

Ex vivo animal study.

METHODS

Microscope-integrated optical coherence tomography was used to obtain 3D visualization of subretinal blebs in porcine eyes at Duke Eye Center. Two different injection phases were imaged and analyzed in 15 eyes (30 volumes), selected from a total of 37 eyes. The inclusion/exclusion criteria were set independently from the algorithm-development and testing team. A novel lightweight, deep learning-based algorithm was designed to segment subretinal bleb boundaries. A cross-validation method was used to avoid selection bias. An ensemble-classifier strategy was applied to generate final results for the test dataset.

RESULTS

The algorithm performs notably better than 4 other state-of-the-art deep learning-based segmentation methods, achieving an F1 score of 93.86 ± 1.17% and 96.90 ± 0.59% on the independent test data for entry and full blebs, respectively.

CONCLUSION

The proposed algorithm accurately segmented the volumetric boundaries of Ringer's lactate solution delivered into the subretinal space of porcine eyes with robust performance and real-time speed. This is the first step for future applications in computer-guided delivery of therapeutics into the subretinal space in human subjects.

Short-term outcomes of patients with neovascular exudative AMD: the effect of COVID-19 pandemic

PURPOSE

To estimate the impact of delayed care during the coronavirus disease 2019 (COVID-19) pandemic on the outcomes of patients with neovascular age-related macular degeneration (AMD).

METHODS

Consecutive patients with diagnosis of neovascular AMD were consecutively enrolled between March 9, 2020, and June 12, 2020, (during and immediately after the Italian COVID-19 quarantine). During the inclusion (or pandemic) visit (V₀), patients received a complete ophthalmologic evaluation, including optical coherence tomography (OCT). Best-corrected visual acuity (BCVA) and OCT findings from the two preceding visits (V_-1 and V_-2) were compared with data at V₀.

RESULTS

One-hundred patients (112 eyes) were enrolled in this study. The time interval between following visits was 110.7 ± 37.5 days within V₀ and V_-1 and 80.8 ± 39.7 days within V_-1 and V_-2, respectively (P < 0.0001). BCVA was statistically worse at the V₀ visit as compared with the immediately preceding (V_-1) visit (0.50 ± 0.43 LogMAR and 0.45 ± 0.38 LogMAR at the V₀ and V_-1 visits, respectively; P = 0.046). On structural OCT, 91 out of 112 (81.2%) neovascular AMD eyes displayed the evidence of exudative disease activity at the V₀ visit, while 77 (68.7%) eyes exhibited signs of exudation at the V_-1 visit (P = 0.022). No differences in terms of BCVA and OCT findings were detected between the V_-1 and V_-2 visits. In multiple regression analysis, the difference in BCVA between V₀ and V_-1 visits was significantly associated with the interval time within these two visits (P = 0.026).

CONCLUSION

The COVID-19 pandemic-related postponement in patient care proved to be significantly associated with worse short-term outcomes in these patients.

IQGAP1 causes choroidal neovascularization by sustaining VEGFR2-mediated Rac1 activation

Loss of visual acuity in neovascular age-related macular degeneration (nAMD) occurs when factors activate choroidal endothelial cells (CECs) to transmigrate the retinal pigment epithelium into the sensory retina and develop into choroidal neovascularization (CNV). Active Rac1 (Rac1GTP) is required for CEC migration and is induced by different AMD-related stresses, including vascular endothelial growth factor (VEGF). Besides its role in pathologic events, Rac1 also plays a role in physiologic functions. Therefore, we were interested in a method to inhibit pathologic activation of Rac1. We addressed the hypothesis that IQGAP1, a scaffold protein with a Rac1 binding domain, regulates pathologic Rac1GTP in CEC migration and CNV. Compared to littermate Iqgap1^+/+, Iqgap1^-/- mice had reduced volumes of laser-induced CNV and decreased Rac1GTP and phosphorylated VEGFR2 (p-VEGFR2) within lectin-stained CNV. Knockdown of IQGAP1 in CECs significantly reduced VEGF-induced Rac1GTP, mediated through p-VEGFR2, which was necessary for CEC migration. Moreover, sustained activation of Rac1GTP induced by VEGF was eliminated when CECs were transfected with an IQGAP1 construct that is unable to bind Rac1. IQGAP1-mediated Src activation was involved in initiating Rac1 activation, CEC migration, and tube formation. Our findings indicate that CEC IQGAP1 interacts with VEGFR2 to mediate Src activation and subsequent Rac1 activation and CEC migration. In addition, IQGAP1 binding to Rac1GTP results in sustained activation of Rac1, leading to CEC migration toward VEGF. Our study supports a role of IQGAP1 and the interaction between IQGAP1 and Rac1GTP to restore CECs quiescence and, therefore, prevent vision-threatening CNV in nAMD.

Intravitreal enzyme replacement preserves retinal structure and function in canine CLN2 neuronal ceroid lipofuscinosis

CLN2 neuronal ceroid lipofuscinosis is a hereditary neurodegenerative disorder characterized by progressive vision loss, neurological decline, and seizures. CLN2 disease results from mutations in TPP1 that encodes the lysosomal enzyme tripeptidyl peptidase-1 (TPP1). Children with CLN2 neuronal ceroid lipofuscinosis experience ocular disease, characterized by progressive retinal degeneration associated with impaired retinal function and gradual vision loss culminating in total blindness. A similar progressive loss of retinal function is also observed in a dog CLN2 model with a TPP1 null mutation. A study was conducted to evaluate the efficacy of periodic intravitreal injections of recombinant human (rh) TPP1 in inhibiting retinal degeneration and preserving retinal function in the canine model. TPP1 null dogs received periodic intravitreal injections of rhTPP1 in one eye and vehicle in the other eye beginning at approximately 12 weeks of age. Ophthalmic exams, in vivo ocular imaging, and electroretinography (ERG) were repeated regularly to monitor retinal structure and function. Retinal histology was evaluated in eyes collected from these dogs when they were euthanized at end-stage neurological disease (43-46 weeks of age). Intravitreal rhTPP1 dosing prevented disease-related declines in ERG amplitudes in the TPP1-treated eyes. At end-stage neurologic disease, TPP1-treated eyes retained normal morphology while the contralateral vehicle-treated eyes exhibited loss of inner retinal neurons and photoreceptor disorganization typical of CLN2 disease. The treatment also prevented the development of disease-related focal retinal detachments observed in the control eyes. Uveitis occurred secondary to the administration of the rhTPP1 but did not hinder the therapeutic benefits. These findings demonstrate that periodic intravitreal injection of rhTPP1 preserves retinal structure and function in canine CLN2 disease.

Influence of pigment epithelial detachment on visual acuity in neovascular age-related macular degeneration

Pigment epithelial detachment (PED), the anatomical separation of the retinal pigment epithelium from the Bruch membrane, is common in many chorioretinal diseases, including neovascular age-related macular degeneration. PED is present in about 30% to 80% of neovascular age-related macular degeneration patients based on the CATT, EXCITE, and VIEW studies. The influence of PED on visual acuity is controversial as a result of inconsistent results reported by various studies. With advances in imaging technologies, it is possible to evaluate not only the presence or absence of PED, but also detailed quantitative parameters, such as height, width, greatest linear diameter, area, volume, and reflectivity within the PED. We performed a comprehensive literature review to evaluate the relationship of PED with visual acuity. In summary, the presence or persistence of a PED may still be compatible with relatively good visual acuity. There is no strong evidence that the presence of a PED or aspects of its morphology has a significant impact on visual acuity. The presence of a PED may be predictive of the need for more regular treatment. More well-designed studies with standardized PED definitions and classifications are needed to evaluate the relationship between PED and visual acuity.

Rapid pathogen identification and antimicrobial susceptibility testing in in vitro endophthalmitis with matrix assisted laser desorption-ionization Time-of-Flight Mass Spectrometry and VITEK 2 without prior culture

PURPOSE

Prompt clinical diagnosis and initiation of treatment are critical in the management of infectious endophthalmitis. Current methods used to identify causative agents of infectious endophthalmitis are mostly inefficient, owing to suboptimal sensitivity, length, and cost. Matrix Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) can be used to rapidly identity pathogens without a need for culture. Similarly, automated antimicrobial susceptibility test systems (AST, VITEK 2) provide accurate antimicrobial susceptibility profiles. In this proof-of-concept study, we apply these technologies for the direct identification and characterization of pathogens in vitreous samples, without culture, as an in vitro model of infectious endophthalmitis.

METHODS

Vitreous humor aspirated from freshly enucleated porcine eyes was inoculated with different inocula of Staphylococcus aureus (S. aureus) and incubated at 37°C. Vitreous endophthalmitis samples were centrifuged and pellets were directly analyzed with MALDI-TOF MS and VITEK 2 without prior culture. S. aureus colonies that were conventionally grown on culture medium were used as control samples. Time-to-identification, minimum concentration of bacteria required for identification, and accuracy of results compared to standard methods were determined.

RESULTS

MALDI-TOF MS achieved accurate pathogen identification from direct analysis of intraocular samples with confidence values of up to 99.9%. Time from sample processing to pathogen identification was <30 minutes. The minimum number of bacteria needed for positive identification was 7.889x106 colony forming units (cfu/μl). Direct analysis of intraocular samples with VITEK 2 gave AST profiles that were up to 94.4% identical to the positive control S. aureus analyzed per standard protocol.

CONCLUSION

Our findings demonstrate that the direct analysis of vitreous samples with MALDI-TOF MS and VITEK 2 without prior culture could serve as new, improved methods for rapid, accurate pathogen identification and targeted treatment design in infectious endophthalmitis. In vivo models and standardized comparisons against other microbiological methods are needed to determine the value of direct analysis of intraocular samples from infectious endophthalmitis with MALDI-TOF MS and VITEK 2.

Undertreatment of Neovascular Age-Related Macular Degeneration after 10 Years of Anti-Vascular Endothelial Growth Factor Therapy in the Real World: The Need for A Change of Mindset

PURPOSE

To assess the gap between visual acuity (VA) outcomes with anti-vascular endothelial growth factor (anti-VEGF) therapies in clinical trials and real-world practice, and explore the reasons for this gap.

METHODS

The literature was searched from January 1, 2013, to June 30, 2018, for studies reporting VA gains and injection frequencies in clinical trials and real-world practice.

RESULTS

Clinical trials of anti-VEGF agents and their extension studies demonstrated initial VA gains maintained at 4 years and beyond (up to 7 years) with continuous proactive treatment. Visual outcomes correlated with injection frequency. In real-world practice, patients are usually undertreated, accounting for the VA decline over time. Reasons for undertreatment include the burden of injections and monitoring visits imposed on patients/caregivers. However, another primary reason is the general mindset in the ophthalmological community that sustained benefits with treatment are not possible, leading to poor compliance and creating a vicious circle.

CONCLUSIONS

Initial VA gains can be maintained with more intensive/proactive approaches. Promising new treatments requiring less frequent injections/monitoring will help in the near future; meanwhile, better results could be achieved by changing the community mindset that contributes to undertreatment.

Twelve-week dosing with Aflibercept in the treatment of neovascular age-related macular degeneration

Purpose

To review published evidence for a treatment interval extension to ≥12-weeks in neovascular macular degeneration treated with intravitreal Aflibercept.

Methods

A systematic search was performed in the NCBI/PubMed database to identify pro- and retrospective studies retrieved by the key terms <exudative> or <neovascular> and <AMD> or <age-related macular degeneration> AND <intravitreal therapy> AND <Aflibercept> and included all papers that used a treat-and-extend (T&E) protocol including a loading phase of 3 intravitreal anti-VEGF injections and a minimal follow-up of 2 years. Disease stability was defined as the absence of any intraocular and absence or stability of subretinal fluid and pigment-epithelial detachment.

Results

Four studies were identified that reported information pertaining to disease stability or treatment extension beyond 12 weeks under intravitreal Aflibercept therapy including 1,102 eyes in total. Following a T&E protocol, a mean of 62.9% achieved disease stability and a 6.9 letter gain based on 11.9 injections over 24 months of Aflibercept treatment. As much as 43.0% of all eyes or 64.1% of the eyes with stable disease were maintained on ≥12-weekly injection intervals.

Conclusions

A consequent treatment with a null tolerance for intraretinal fluid is prerequisite to induce stability and maintain visual gain after the loading phase. Using Aflibercept in a T&E protocol, disease stability and interval extension to ≥12 weeks were reported in 43% of the eyes by end of the second year with less injections, but similar results as under fix dosing. A lower treatment burden strongly argues for an individualized proactive treatment regimen.

The Effectiveness of 0.6% Povidone Iodine Eye Drops in Reducing the Conjunctival Bacterial Load and Needle Contamination in Patients Undergoing Anti-VEGF Intravitreal Injection: A Prospective, Randomized Study

The study purpose was to assess the efficacy of a preservative-free 0.6% povidone iodine eye drops as perioperative prophylactic treatment for reducing conjunctival bacterial load and the rate of needle contamination in patients undergoing intravitreal anti-vascular endothelial growth factor injection. Enrolled patients were randomized to either the study group (0.6% povidone iodine, three day-prophylactic treatment before the injection) or to the control group (placebo, three day-prophylactic treatment). Conjunctival swabs were obtained before and after the prophylactic treatment in both groups. Intravitreal injections were performed in a sterile fashion. The injection needle and a control needle were collected for microbiological culture. Data from 254 and 253 eyes in the study group and control group, respectively, were analyzed. Bacterial growth from conjunctival swab cultures was significantly lower after 0.6% povidone iodine prophylaxis compared to baseline and to placebo prophylaxis (p < 0.001), showing an 82% eradication rate in the study group. No injection needle showed bacterial contamination in the study group, whereas six needles were culture-positive in the control group (p = 0.015). No serious ocular and non-ocular adverse events were recorded. The 0.6% povidone iodine solution proved an effective treatment in reducing conjunctival bacterial load and risk of needle contamination.

Cytomegalovirus retinitis in children and adolescents with acute leukemia following allogeneic hematopoietic stem cell transplantation

Cytomegalovirus retinitis (CMVR) may occur after allogeneic hematopoietic stem cell transplantation (HSCT). However, little is known about its incidence, strategies for ophthalmic surveillance, and timely implementation of adequate antiviral treatment in pediatric allogeneic HSCT recipients. We provide a retrospective analysis of the epidemiology and clinical features of CMVR in pediatric allogeneic HSCT patients transplanted at our center over a 16-year period. Two patients of this cohort with leukemia are presented. Our analysis is supplemented by a systematic review on pediatric patients with leukemia and CMVR in the setting of allogeneic HSCT. The overall incidence of CMVR in our cohort was 1% (4/338) and 14.2% (3/21) in leukemic patients. In published cases, CMVR occurred at a median of 143 days after transplantation, and, in the majority of patients, was preceded by CMV detection in blood by a median of 93 days. Continued immune suppression following engraftment likely triggers CMVR. Preemptive treatment with ganciclovir as standard is usually successful. Foscarnet is used in case of resistance to ganciclovir or drug-induced granulocytopenia. Overall, CMVR after HSCT in pediatric leukemic patients is rare, but a potentially higher vulnerability of this population for involvement of the eye warrants a standardized ophthalmological examination plan.

A Multinational Comparison of Anti-Vascular Endothelial Growth Factor Use: The United States, the United Kingdom, and Asia-Pacific

PURPOSE

A comparison of anti-vascular endothelial growth factor (anti-VEGF) medication use across multiple countries.

CLINICAL RELEVANCE

Anti-VEGF medication use is now considered first-line treatment for numerous retinal diseases globally. Exploring medication choices, costs within each healthcare system, policy challenges, emerging treatments, and patient access all provide insight into a newly recognized and major public health issue.

METHODS

All data presented in this review are available through the published English literature in PubMed, non-peer-reviewed trade publications, and reported surveys. The following search terms were used: anti-VEGF OR bevacizumab OR ranibizumab OR aflibercept OR pegaptanib OR conbercept AND trends OR survey OR cost OR patterns OR preference. Countries with large populations and available data included the United States, United Kingdom, China, India, Korea, Singapore, and Australia. Population and economic statistics were obtained from published reports from the World Bank, World Health Organization, and Commonwealth Fund.

RESULTS

Anti-VEGF medication use and costs are significant aspects of patient and healthcare system expenditures in each nation and may have an especially large potential economic burden in India and China. Bevacizumab use comprises the majority of anti-VEGF medication use in the United States and Singapore, although aflibercept use is growing rapidly. Paradoxically, data demonstrate that there is a significant trend in medication choice toward ranibizumab and aflibercept among practice settings outside of the United States, such as the United Kingdom, China, South Korea, and Australia. The price of anti-VEGF medications ranged from US $30 (ziv-aflibercept) to US $1950 (ranibizumab and aflibercept). Ranibizumab's price ranged from US $240 in India to US $1950 in the United States. Conbercept in China costs approximately US $1150 per dose.

CONCLUSIONS

Outside of the United States, many nations are using a majority of more expensive anti-VEGF medications, which may lead to increased costs and decreased access. Increasing the availability of safely compounded anti-VEGF medications will likely improve access, create patient/provider choice, and decrease relative healthcare costs for the growing burden of retinal diseases globally.

Gene therapy knockdown of VEGFR2 in retinal endothelial cells to treat retinopathy

Inhibition of vascular endothelial growth factor (VEGF) in retinopathy of prematurity (ROP) raises concerns for premature infants because VEGF is essential for retinovascular development as well as neuronal and glial health. This study tested the hypothesis that endothelial cell-specific knockdown of VEGF receptor 2 (VEGFR2), or downstream STAT3, would inhibit VEGF-induced retinopathy without delaying physiologic retinal vascular development. We developed an endothelial cell-specific lentiviral vector that delivered shRNAs to VEGFR2 or STAT3 and a green fluorescent protein reporter under control of the VE-cadherin promoter. The specificity and efficacy of the lentiviral vector-driven shRNAs were validated in vitro and in vivo. In the rat oxygen-induced retinopathy model highly representative of human ROP, the effects of endothelial cell knockdown of VEGFR2 or STAT3 were determined on intravitreal neovascularization (IVNV), physiologic retinal vascular development [assessed as area of peripheral avascular/total retina (AVA)], retinal structure, and retinal function. Targeted knockdown of VEGFR2 or STAT3 specifically in retinal endothelial cells by subretinal injection of lentiviral vectors into postnatal day 8 rat pup eyes efficiently inhibited IVNV, and knockdown of VEGFR2 also reduced AVA and increased retinal thickness without altering retinal function. Taken together, our results support specific knockdown of VEGFR2 in retinal endothelial cells as a novel therapeutic method to treat retinopathy.