THE ABILITY OF ARTIFICIAL INTELLIGENCE CHATBOTS ChatGPT AND GOOGLE BARD TO ACCURATELY CONVEY PREOPERATIVE INFORMATION FOR PATIENTS UNDERGOING OPHTHALMIC SURGERIES

INTRODUCTION

To determine whether the two popular artificial intelligence chatbots, ChatGPT and Bard, can provide high-quality information concerning procedure description, risks, benefits, and alternatives of various ophthalmic surgeries.

METHODS

ChatGPT and Bard were prompted with questions pertaining to the description, potential risks, benefits, alternatives, and implications of not proceeding with various surgeries in different subspecialties of ophthalmology. Six common ophthalmic procedures were included in the authors' analysis. Two comprehensive ophthalmologists and one subspecialist graded each response independently using a 5-point Likert scale.

RESULTS

Likert grading for accuracy was significantly higher for ChatGPT in comparison with Bard (4.5 ± 0.6 vs. 3.8 ± 0.8, P < 0.0001). Generally, ChatGPT performed better than Bard even when questions were stratified by the type of ophthalmic surgery. There was no significant difference between ChatGPT and Bard for response length (2,104.7 ± 271.4 characters vs. 2,441.0 ± 633.9 characters, P = 0.12). ChatGPT responded significantly slower than Bard (46.0 ± 3.0 vs. 6.6 ± 1.2 seconds, P < 0.0001).

CONCLUSION

Both ChatGPT and Bard may offer accessible and high-quality information relevant to the informed consent process for various ophthalmic procedures. Nonetheless, both artificial intelligence chatbots overlooked the probability of adverse events, hence limiting their potential and introducing patients to information that may be difficult to interpret.

Google Gemini and Bard artificial intelligence chatbot performance in ophthalmology knowledge assessment

PURPOSE

With the popularization of ChatGPT (Open AI, San Francisco, California, United States) in recent months, understanding the potential of artificial intelligence (AI) chatbots in a medical context is important. Our study aims to evaluate Google Gemini and Bard's (Google, Mountain View, California, United States) knowledge in ophthalmology.

METHODS

In this study, we evaluated Google Gemini and Bard's performance on EyeQuiz, a platform containing ophthalmology board certification examination practice questions, when used from the United States (US). Accuracy, response length, response time, and provision of explanations were evaluated. Subspecialty-specific performance was noted. A secondary analysis was conducted using Bard from Vietnam, and Gemini from Vietnam, Brazil, and the Netherlands.

RESULTS

Overall, Google Gemini and Bard both had accuracies of 71% across 150 text-based multiple-choice questions. The secondary analysis revealed an accuracy of 67% using Bard from Vietnam, with 32 questions (21%) answered differently than when using Bard from the US. Moreover, the Vietnam version of Gemini achieved an accuracy of 74%, with 23 (15%) answered differently than the US version of Gemini. While the Brazil (68%) and Netherlands (65%) versions of Gemini performed slightly worse than the US version, differences in performance across the various country-specific versions of Bard and Gemini were not statistically significant.

CONCLUSION

Google Gemini and Bard had an acceptable performance in responding to ophthalmology board examination practice questions. Subtle variability was noted in the performance of the chatbots across different countries. The chatbots also tended to provide a confident explanation even when providing an incorrect answer.

Tap and inject of intravitreal antibiotics versus pars plana vitrectomy for post-cataract surgery endophthalmitis: a meta-analysis

BACKGROUND

The efficacy and safety of initial tap and inject (T/I) compared with pars plana vitrectomy (PPV) for acute postoperative bacterial endophthalmitis following cataract surgery is unclear. Understanding the comparative safety and efficacy of initial T/I and initial PPV can provide context for treatment decision making in this setting.

METHODS

A systematic literature search was performed on Ovid MEDLINE, EMBASE, and the Cochrane Library from January 1990 to January 2021. Comparative studies reporting on final best-corrected visual acuity (BCVA) following initial T/I or PPV in patients with infectious endophthalmitis secondary to cataract surgery were included. Cochrane's Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-I) was used to evaluate the risk of bias, and GRADE criteria were used to assess certainty of evidence. A random-effects model was used for meta-analysis.

RESULTS

Seven nonrandomized studies reporting on 188 eyes at baseline were included in this meta-analysis. Initial T/I achieved a significantly better BCVA at last study observation than initial PPV (weighted mean difference [WMD] = -0.61 logMAR; 95% CI, -1.19 to -0.03; p = 0.04; I2 = 89%; n = 7 studies; GRADE = very low). The incidence of enucleation was similar between initial T/I and initial PPV (risk ratio [RR] = 0.73; 95% CI, 0.09-6.25; p = 0.78; I2 = 4%; n = 2 studies; GRADE = very low). The risk of retinal detachment was similar between treatment modalities (RR = 0.29; 95% CI, 0.01-5.94; p = 0.42; I2 = 52%; n = 2 studies; GRADE = very low).

CONCLUSIONS

The quality of evidence in this setting is limited. T/I had a significantly better BCVA at last study observation than initial PPV. Safety profiles were similar between T/I and PPV.

Accuracy of an Artificial Intelligence Chatbot's Interpretation of Clinical Ophthalmic Images

Importance

Ophthalmology is reliant on effective interpretation of multimodal imaging to ensure diagnostic accuracy. The new ability of ChatGPT-4 (OpenAI) to interpret ophthalmic images has not yet been explored.

Objective

To evaluate the performance of the novel release of an artificial intelligence chatbot that is capable of processing imaging data.

Design, Setting, and Participants

This cross-sectional study used a publicly available dataset of ophthalmic cases from OCTCases, a medical education platform based out of the Department of Ophthalmology and Vision Sciences at the University of Toronto, with accompanying clinical multimodal imaging and multiple-choice questions. Across 137 available cases, 136 contained multiple-choice questions (99%).

Exposures

The chatbot answered questions requiring multimodal input from October 16 to October 23, 2023.

Main Outcomes and Measures

The primary outcome was the accuracy of the chatbot in answering multiple-choice questions pertaining to image recognition in ophthalmic cases, measured as the proportion of correct responses. χ2 Tests were conducted to compare the proportion of correct responses across different ophthalmic subspecialties.

Results

A total of 429 multiple-choice questions from 136 ophthalmic cases and 448 images were included in the analysis. The chatbot answered 299 of multiple-choice questions correctly across all cases (70%). The chatbot's performance was better on retina questions than neuro-ophthalmology questions (77% vs 58%; difference = 18%; 95% CI, 7.5%-29.4%; χ21 = 11.4; P < .001). The chatbot achieved a better performance on nonimage-based questions compared with image-based questions (82% vs 65%; difference = 17%; 95% CI, 7.8%-25.1%; χ21 = 12.2; P < .001).The chatbot performed best on questions in the retina category (77% correct) and poorest in the neuro-ophthalmology category (58% correct). The chatbot demonstrated intermediate performance on questions from the ocular oncology (72% correct), pediatric ophthalmology (68% correct), uveitis (67% correct), and glaucoma (61% correct) categories.

Conclusions and Relevance

In this study, the recent version of the chatbot accurately responded to approximately two-thirds of multiple-choice questions pertaining to ophthalmic cases based on imaging interpretation. The multimodal chatbot performed better on questions that did not rely on the interpretation of imaging modalities. As the use of multimodal chatbots becomes increasingly widespread, it is imperative to stress their appropriate integration within medical contexts.

Preoperative Visual Acuity Thresholds in Pars Plana Vitrectomy for Epiretinal Membrane: A Systematic Review

BACKGROUND AND OBJECTIVE

This review consolidates findings from studies that used a preoperative visual acuity (VA) threshold as an indication for epiretinal membrane (ERM) surgery.

METHODS

The literature was systematically searched using Ovid MEDLINE, EMBASE, and Cochrane Library from January 2000 to October 2022 to select studies reporting on pars plana vitrectomy (PPV) for ERM that used a preoperative VA threshold as an inclusion criterion. Primary outcomes were final best-corrected visual acuity (BCVA) and change in BCVA relative to baseline. Secondary outcomes included risk of intra- and postoperative complications.

RESULTS

A total of 639 eyes from seven studies were included. The most liberal preoperative VA threshold was 20/28.5 or worse, whereas the most conservative threshold was worse than 20/60. The mean preoperative BCVA was 0.55 logarithm of the minimum angle of resolution (logMAR) (∼20/70), and the mean postoperative BCVA was 0.35 logMAR (∼20/45). Generally, VA improved relative to baseline, regardless of the preoperative VA threshold. The smallest improvement in VA was observed in a study where the pre-operative VA to consider surgery was liberal (20/30 or worse), whereas the greatest VA improvement was observed in a study that used a conservative preoperative VA threshold (worse than 20/60).

CONCLUSIONS

The greatest improvement in BCVA was observed in studies where a conservative pre-operative VA threshold was used. The decision to operate should involve a patient-centered approach with a thorough discussion of the risks and benefits of PPV, regardless of the preoperative VA threshold used. [Ophthalmic Surg Lasers Imaging Retina 2024;55:xx-xx.].

PARS PLANA VITRECTOMY WITH OR WITHOUT INTERNAL LIMITING MEMBRANE PEEL FOR MACULAR HOLE: A Systematic Review and Meta-Analysis

PURPOSE

To compare the efficacy and safety of pars plana vitrectomy with and without internal limiting membrane (ILM) peeling for macular hole (MH).

METHODS

A systematic literature search on Ovid MEDLINE, Embase, Cochrane Library, and Google Scholar was performed from January 2000 to 2023. The primary outcome was the final best-corrected visual acuity (BCVA). Secondary outcomes included MH closure rates and the need for repeat surgery. The authors performed a random-effects meta-analysis on Review Manager 5.4.

RESULTS

Fourteen studies on 880 eyes were included. Pars plana vitrectomy with and without ILM peel achieved a similar final BCVA ( P = 0.66). However, pars plana vitrectomy without ILM peeling achieved a significantly better final BCVA in eyes with closed MHs (WMD = 0.05 logMAR, 95% CI, 0.01-0.10, P = 0.02). Pars plana vitrectomy with ILM peeling achieved a significantly higher primary MH closure rate (RR = 1.21, 95% CI, 1.04-1.42, P = 0.02) and lower incidence of MH reoperation (RR = 0.19, 95% CI, 0.11-0.33, P < 0.001). The final MH closure rate ( P = 0.12) and incidence of MH recurrence ( P = 0.25) were similar between groups.

CONCLUSION

Pars plana vitrectomy with and without ILM peel achieved a similar final BCVA. However, pars plana vitrectomy without ILM peeling achieved a better final BCVA in eyes with closed MHs. ILM peeling achieved a greater primary MH closure rate and reduced need for reoperation.

Association Between Sociodemographic Factors and Self-reported Glaucoma in the National Health Interview Survey: A Population-Based Analysis

PURPOSE

To investigate the association between social determinants of health (SDH) in the domains of social and community context, education access, environmental context, economic stability, and healthcare access, with glaucoma prevalence.

DESIGN

Cross-sectional study.

METHODS

The study population consisted of adult participants who answered glaucoma-related questions on the 2017 National Health Interview Survey (NHIS), the most recent iteration that includes glaucoma-related questions. The main outcome measures included the relationships between SDH-related factors and self-reported glaucoma diagnosis as well as self-reported glaucomatous vision loss were examined using univariable and multivariable regression models.

RESULTS

In total, 26,696 of 26,742 (99.83%) NHIS respondents were included, of whom 880 (3.30%) reported a glaucoma diagnosis and 275 (1.03%) reported glaucomatous vision loss. Participants were predominantly middle-aged (50.95 ± 18.60 years), female (54.75%), and non-Hispanic White (70.49%). In age-adjusted multivariable regression (n = 25,456), non-Hispanic Black race (odds ratio [OR] = 1.87, 99% CI = [1.37, 2.55], P < .001, compared to non-Hispanic White race) and poor health status (OR = 1.54, 99% CI = [1.00, 2.37], P = .01, compared to good health status) were significant predictors of glaucoma diagnosis. For glaucomatous vision loss, having an income below the poverty threshold (OR = 2.41, 99% CI = [1.12, 5.20], P = .003, compared to income ≥5 times the poverty threshold) was the only significant predictor in univariable analyses. No SDH-related factors were significantly associated with glaucomatous vision loss in multivariable analysis (n = 848). Multicollinearity was minimal (variation inflation factor<1.6 for all independent variables).

CONCLUSIONS

Non-Hispanic Black race and poor health status were associated with self-reported glaucoma diagnosis. Physicians and policymakers may consider SDH when assessing clinical risk and designing public health interventions.

Anti-vascular endothelial growth factor therapy and retinal non-perfusion in diabetic retinopathy: A meta-analysis of randomised trials

PURPOSE

Retinal non-perfusion (RNP) is fundamental to disease onset and progression in diabetic retinopathy (DR). Whether anti-vascular endothelial growth factor (anti-VEGF) therapy can modify RNP progression is unclear. This investigation quantified the impact of anti-VEGF therapy on RNP progression compared with laser or sham at 12 months.

METHODS

A systematic review and meta-analysis of randomised controlled trials (RCTs) were performed; Ovid MEDLINE, EMBASE and CENTRAL were searched from inception to 4th March 2022. The change in any continuous measure of RNP at 12 months and 24 months was the primary and secondary outcomes, respectively. Outcomes were reported utilising standardised mean differences (SMD). The Cochrane Risk of Bias Tool version-2 and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines informed risk of bias and certainty of evidence assessments.

RESULTS

Six RCTs (1296 eyes) and three RCTs (1131 eyes) were included at 12 and 24 months, respectively. Meta-analysis demonstrated that RNP progression may be slowed with anti-VEGF therapy compared with laser/sham at 12 months (SMD: -0.17; 95% confidence interval [CI]: -0.29, -0.06; p = 0.003; I2  = 0; GRADE rating: LOW) and 24-months (SMD: -0.21; 95% CI: -0.37, -0.05; p = 0.009; I2  = 28%; GRADE rating: LOW). The certainty of evidence was downgraded due to indirectness and due to imprecision.

CONCLUSION

Anti-VEGF treatment may slightly impact the pathophysiologic process of progressive RNP in DR. The dosing regimen and the absence of diabetic macular edema may impact this potential effect. Future trials are needed to increase the precision of the effect and inform the association between RNP progression and clinically important events.

PROSPERO REGISTRATION

CRD42022314418.

Artificial Intelligence Chatbots' Understanding of the Risks and Benefits of Computed Tomography and Magnetic Resonance Imaging Scenarios

PURPOSE

Patients may seek online information to better understand medical imaging procedures. The purpose of this study was to assess the accuracy of information provided by 2 popular artificial intelligence (AI) chatbots pertaining to common imaging scenarios' risks, benefits, and alternatives.

METHODS

Fourteen imaging-related scenarios pertaining to computed tomography (CT) or magnetic resonance imaging (MRI) were used. Factors including the use of intravenous contrast, the presence of renal disease, and whether the patient was pregnant were included in the analysis. For each scenario, 3 prompts for outlining the (1) risks, (2) benefits, and (3) alternative imaging choices or potential implications of not using contrast were inputted into ChatGPT and Bard. A grading rubric and a 5-point Likert scale was used by 2 independent reviewers to grade responses. Prompt variability and chatbot context dependency were also assessed.

RESULTS

ChatGPT's performance was superior to Bard's in accurately responding to prompts per Likert grading (4.36 ± 0.63 vs 3.25 ± 1.03 seconds, P < .0001). There was substantial agreement between independent reviewer grading for ChatGPT (κ = 0.621) and Bard (κ = 0.684). Response text length was not statistically different between ChatGPT and Bard (2087 ± 256 characters vs 2162 ± 369 characters, P = .24). Response time was longer for ChatGPT (34 ± 2 vs 8 ± 1 seconds, P < .0001).

CONCLUSIONS

ChatGPT performed superior to Bard at outlining risks, benefits, and alternatives to common imaging scenarios. Generally, context dependency and prompt variability did not change chatbot response content. Due to the lack of detailed scientific reasoning and inability to provide patient-specific information, both AI chatbots have limitations as a patient information resource.

Association Between Vision Difficulty and Sociodemographic Factors in Children: A Population-Based Analysis

PURPOSE

To determine sociodemographic predictors of poor vision in children and adolescents less than 18 years of age in a large, nationally representative sample of the US population.

DESIGN

Retrospective, population-based cross-sectional study.

METHODS

Using data from the 2021 National Health Interview Survey (NHIS), participants less than 18 years of age for whom data were available on vision difficulty were included in our analysis. Our primary outcome was vision difficulty. Sociodemographic variables were investigated as predictors of vision difficulty. Logistic regression models were performed using Stata version 17.0. An odds ratio (OR) and 95% CI were reported for analyses.

RESULTS

The 2021 NHIS reported on 8261 children and adolescents, of whom 7373 had data pertaining to vision difficulty and were included in our sample. Vision difficulty was associated with being unable to afford medical care (OR = 2.60, 95% CI = 1.17, 5.80, P = 0.02) and having public health insurance (OR = 1.52, 95% CI = 1.09, 2.12, P = .01). Compared to children less than 5 years of age, children ranging from 5 to 8 years (OR = 4.29, 95% CI = 2.26, 8.15, P < .01) and adolescents ranging from 16 to 17 years (OR = 6.06, 95% CI = 3.17, 11.58, P < .01) had a higher odds of vision difficulty. Compared to participants for whom the highest level of education of adults in their family was grade 1 to 11, the odds of vision difficulty were lower in those whose parents had a professional school or doctoral degree (OR = 0.30, 95% CI = 0.11, 0.84, P = .02).

CONCLUSIONS

Multiple sociodemographic factors are associated with vision difficulty in young persons. In working toward achieving equity in vision health, it is imperative that disparities mediated by sociodemographic factors be addressed through public health policies.

Histological changes in retinal detachment: A systematic review for the clinician

Although there have been numerous innovations in the management of retinal detachment (RD) over the past decades, there is still limited understanding of the pathophysiological processes that take place before and after repair. Summarizing key concepts using animal studies may allow for a better assessment of common pre- and postoperative microstructural abnormalities in RD. We performed a systematic literature review on Ovid MEDLINE, EMBASE, and Cochrane Controlled Register of Trials from January 1968 to January 2022, searching animal or human studies reporting retinal histologic changes following primary or induced RD. Thirty-two studies were included. Main cellular events were summarized: photoceptor apoptosis occurs as early as 12 hours after RD and, although most cells survive, there is extensive remodeling. Outer segments progressively degenerate, while inner segments are reorganized. Rod and cone opsins are redistributed, and rod axons retract while cones undergo changes in shape. Second- and third-order neurons rearrange their dendritic processes, and Müller cells become hypertrophic, growing into the subretinal space. Finally, retinal pigment epithelium cells undergo a change in their morphology. Acknowledging critical morphologic changes following RD is crucial in understanding why anatomical and functional outcomes can vary. Insights from histological studies, together with high-resolution imaging, may be key in identifying novel biomarkers in RD.

Understanding the diagnosis of superior mesenteric artery syndrome: analysis of the location of duodenal impression on upper gastrointestinal studies

BACKGROUND

Upper gastrointestinal (GI) contrast studies are frequently requested to aid superior mesenteric artery syndrome diagnosis, a rare entity. Compression of the third duodenal part is expected to be mid-to-left of the midline where the superior mesenteric artery arises from the aorta; however, a duodenal impression to the right of the midline due to normal anatomic impression by the inferior vena cava (IVC) is often encountered and frequently misdiagnosed.

OBJECTIVE

The purpose of this study was to determine the frequencies of (1) normal right-of-midline duodenal impressions and (2) mid-to-left of midline compressions in upper GI studies in a tertiary pediatric referral center.

MATERIALS AND METHODS

All upper GI studies performed at our institution over 2 years were retrospectively evaluated to determine whether the duodenum had vertical duodenal impression to the right of the vertebral midline, mid-to-left of the vertebral midline, or no identifiable duodenal impression at all.

RESULTS

In total, 538 upper GI studies were included in this analysis. A total of 275 male and 247 female patients between 0 and 17 years of age (median: 6 years, range: 1 month-17 years) were included. Of 538 total upper GI studies, there were 240 studies (44.6%) with a right-of-midline impression. There were only 10 studies (1.9%) with a mid-to-left of midline compression, and 9/10 also showed a concurrent right-sided impression sign.

CONCLUSION

Right-of-midline duodenal impression is a normal anatomic finding caused by the IVC and should not be confused with superior mesenteric artery syndrome. In the presence of an appropriate clinical context, proximal duodenal dilation, "to-and-fro" motion of contrast, and duodenal impression at mid-to-left of midline, a diagnosis of superior mesenteric artery syndrome should be considered.

Periorbital Necrotizing Fasciitis: Case Presentation

Necrotizing fasciitis (NF) is an aggressive and potentially life-threatening infection of the superficial fascia and surrounding skin, fat, fascia, muscle, and other soft tissue structures. Here, we outline the rare case of a 26-year-old man with a periorbital Streptococcus pyogenes A NF infection. Our case report underscores a unique instance of periorbital NF, distinctively presenting without any predisposing risk factors, shedding light on its presentation, treatment, and pathophysiology.

Pars Plana Vitrectomy with or without Internal Limiting Membrane Peel for Epiretinal Membrane: A Systematic Review and Meta-Analysis

BACKGROUND

The safety and effectiveness of pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling remains poorly understood for the treatment of epiretinal membrane (ERM).

OBJECTIVES

Our study aims to compare the safety and effectiveness of PPV with and without ILM peeling for ERM.

METHODS

A systematic literature search was conducted on Ovid MEDLINE, Embase, Cochrane Library, and Google Scholar from January 2000 to January 2023 for comparative studies reporting visual and anatomical outcomes for patients with ERM that received PPV with or without ILM peeling. Primary outcomes included best-corrected visual acuity (BCVA) at last study observation and change in BCVA from baseline. Secondary outcomes included retinal thickness (RT) at last study observation, change in RT from baseline, risk of ERM recurrence, and adverse events. A random-effects meta-analysis was performed. Risk of bias of randomized controlled trials was assessed using the Risk of Bias 2 tool of observational studies using the Risk of Bias in Non-randomized Studies of Interventions-I tool. The certainty of evidence of outcomes was evaluated using Grading of Recommendations, Assessment, Development and Evaluation criteria.

RESULTS

Nineteen studies reporting on 1,291 eyes at baseline were included. PPV with and without ILM peel achieved a similar BCVA at last study observation (p = 0.68) and change in BCVA from baseline (p = 0.79). These findings remained consistent irrespective of whether simultaneous phacoemulsification was performed. PPV with ILM peel achieved a significantly lower incidence of ERM recurrence (risk ratio [RR] = 0.26, 95% CI = [0.13, 0.51], p < 0.0001) and additional surgery (RR = 0.17, 95% CI = [0.04, 0.74], p = 0.02) compared to PPV without ILM peel.

CONCLUSION

PPV with and without ILM peel achieved a similar BCVA at last study observation in ERM patients. Patients treated with PPV and ILM peel also had a reduced risk of ERM recurrence and lower reoperation risk. These conclusions are associated with a moderate certainty of evidence and potential for bias from multiple non-randomized studies.

Efficacy and safety of anti-vascular endothelial growth agents for the treatment of polypoidal choroidal vasculopathy: A systematic review and meta-analysis

There remains limited agreement regarding the efficacy and safety of different antivascular endothelial growth factor (anti-VEGF) agents for the management of polypoidal choroidal vasculopathy (PCV). Our meta-analysis compares different anti-VEGF agents for PCV treatment. Ovid MEDLINE, EMBASE, and Cochrane Library were systematically searched from January 2000 to July 2022. We included articles comparing the efficacy and safety of different anti-VEGF agents, specifically bevacizumab (BEV), ranibizumab (RAN), aflibercept AFL), and brolucizumab (BRO), for patients with PCV. 10,440 studies were identified, 122 underwent full-text review, and seven were included. One study was a randomized trial, and six were observational studies. Ranibizumab and aflibercept were associated with a similar best-corrected visual acuity (BCVA) at the last visit in three observational studies (P = 0.10), similar retinal thickness at the last visit in two observational studies (P = 0.85). One observational study comparing BEV versus RAN found comparable outcomes for final BCVA, retinal thickness, and polyp regression. One randomized trial on BRO versus AFL found comparable outcomes for improvement in BCVA, while anatomical outcomes favored BRO. The available evidence suggests that final BCVA is comparable across different anti-VEGF agents, however, further investigation is warranted due to paucity of evidence.

Anti-Vascular Endothelial Growth Factor Therapy Regimens for Polypoidal Choroidal Vasculopathy: A Systematic Review

INTRODUCTION

There are no guidelines on the optimal anti-vascular endothelial growth factor (anti-VEGF) monotherapy regimen for patients with polypoidal choroidal vasculopathy (PCV). In this study, we aimed to assess the comparative safety and efficacy of different treatment regimens of anti-VEGF monotherapy for PCV.

METHODS

We conducted a systematic literature search on Ovid MEDLINE, Embase, and Cochrane Library from January 2000 to May 2023 for comparative articles reporting on different treatment regimens of anti-VEGF agents in PCV. Our primary outcomes were the final best-corrected visual acuity (BCVA) and the change in BCVA from baseline. Secondary outcomes were the final retinal thickness (RT), the change in RT from baseline, the rate of polyp closure, and the incidence of adverse events.

RESULTS

A total of 10,440 studies were screened, and seven studies reporting on 636 eyes with PCV at baseline were included in this systematic review. One RCT of 53 eyes found a similar final BCVA, change in BCVA from baseline, final RT, and complete polyp closure rate between a treat-and-extend (T&E) regimen and a bimonthly fixed-dosing regimen of aflibercept. This trial also found superiority of T&E for change in RT from baseline. One observational study of 33 eyes found a similar BCVA at last study observation between a pro re nata (PRN) regimen and bimonthly fixed-dosing regimen of aflibercept. One observational study of 42 eyes found a similar change in BCVA from baseline and complete polyp closure rate between a PRN regimen and bimonthly fixed-dosing regimen of aflibercept. One RCT of 249 eyes found a similar change in BCVA and RT from baseline, as well as polyp closure, between a T&E regimen and fixed 12-week dosing regimen of conbercept. One observational study of 30 eyes found a superiority of T&E aflibercept for change in BCVA and risk of polyp recurrence, compared to a PRN regimen.

CONCLUSION

Overall, there is a paucity of evidence comparing various treatment regimens of anti-VEGF therapy in patients with PCV. This limited evidence suggests that current treatment regimens are similarly efficacious, though T&E aflibercept achieved superior outcomes when compared to bimonthly dosing or PRN in some individual studies. Further trials are needed to confirm or refute these findings.

Intravitreal Triamcinolone Acetonide for Diabetic Macular Edema and Macular Edema Secondary to Retinal Vein Occlusion: A Meta-Analysis

BACKGROUND

The comparative safety and efficacy of different doses of intravitreal triamcinolone acetonide (IVTA) for diabetic macular edema (DME) and macular edema (ME) secondary to retinal vein occlusion (RVO) is unclear.

OBJECTIVES

This meta-analysis aimed to compare the safety and efficacy of different doses of IVTA in this setting.

METHODS

A systematic literature search for randomized clinical trials (RCTs) was conducted on Cochrane Library, Ovid MEDLINE, and EMBASE from January 2005 to May 2022. Studies that reported on patients with DME or ME secondary to RVO that received treatment with different doses of IVTA were included. A random-effects meta-analysis was performed. Cochrane's Risk of Bias Tool 2 was used to assess the risk of bias, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) guidelines were used to assess certainty of evidence.

RESULTS

Five RCTs reporting on 1,041 eyes at baseline were included in this meta-analysis. In eyes with ME secondary to RVO, high-dose (4 mg) IVTA achieved a significantly better change in best-corrected visual acuity (WMD = -4.75 ETDRS letters, 95% CI = [-7.73, -1.78], p = 0.002) and reduction in retinal thickness (WMD = -93.02 μm, 95% CI = [-153.23, -32.82], p = 0.002) at months 4-6 compared to low-dose (1-2 mg) IVTA. However, high-dose IVTA had a higher risk of intraocular pressure-related adverse events (RR = 2.99, 95% CI = [1.05, 8.50], p = 0.04) and cataract surgery (RR = 5.67, 95% CI = [3.09, 10.41], p < 0.00001) than low-dose IVTA in eyes with ME secondary to RVO. These efficacy and safety differences in high-dose and low-dose IVTA were not observed in DME eyes.

CONCLUSIONS

The RCT evidence in this setting is limited. High-dose IVTA achieved greater improvements in visual acuity and reductions in retinal thickness than low-dose IVTA at months 4-6. However, high-dose IVTA had a less favorable safety profile than low-dose IVTA. The significance of these outcomes was based on patients with ME secondary to RVO, but not DME.

Comparative Performance of ChatGPT and Bard in a Text-Based Radiology Knowledge Assessment

PURPOSE

Bard by Google, a direct competitor to ChatGPT, was recently released. Understanding the relative performance of these different chatbots can provide important insight into their strengths and weaknesses as well as which roles they are most suited to fill. In this project, we aimed to compare the most recent version of ChatGPT, ChatGPT-4, and Bard by Google, in their ability to accurately respond to radiology board examination practice questions.

METHODS

Text-based questions were collected from the 2017-2021 American College of Radiology's Diagnostic Radiology In-Training (DXIT) examinations. ChatGPT-4 and Bard were queried, and their comparative accuracies, response lengths, and response times were documented. Subspecialty-specific performance was analyzed as well.

RESULTS

318 questions were included in our analysis. ChatGPT answered significantly more accurately than Bard (87.11% vs 70.44%, P < .0001). ChatGPT's response length was significantly shorter than Bard's (935.28 ± 440.88 characters vs 1437.52 ± 415.91 characters, P < .0001). ChatGPT's response time was significantly longer than Bard's (26.79 ± 3.27 seconds vs 7.55 ± 1.88 seconds, P < .0001). ChatGPT performed superiorly to Bard in neuroradiology, (100.00% vs 86.21%, P = .03), general & physics (85.39% vs 68.54%, P < .001), nuclear medicine (80.00% vs 56.67%, P < .01), pediatric radiology (93.75% vs 68.75%, P = .03), and ultrasound (100.00% vs 63.64%, P < .001). In the remaining subspecialties, there were no significant differences between ChatGPT and Bard's performance.

CONCLUSION

ChatGPT displayed superior radiology knowledge compared to Bard. While both chatbots display reasonable radiology knowledge, they should be used with conscious knowledge of their limitations and fallibility. Both chatbots provided incorrect or illogical answer explanations and did not always address the educational content of the question.

Hypotony and Anterior Uveitis following Dual Therapy with Nivolumab and Ipilimumab for Metastatic Melanoma: A Case Report

Purpose

To describe a rare case of hypotony and anterior uveitis following dual therapy with nivolumab and ipilimumab for metastatic melanoma.

Methods

Case report.

Results

Here, we present the case of a 64-year-old man taking nivolumab and ipilimumab dual therapy for BRAF+ (v-raf murine sarcoma viral oncogene homolog B1) metastatic melanoma. After treatment for 3 months, he presented to the ophthalmology clinic with bilateral intraocular pressures of 1 mmHg, bilateral keratic precipitates, cataracts, posterior synechiae, and anterior chamber inflammation. He improved with topical medications and the cessation of immunotherapy.

Conclusions

Immunotherapies are a novel class of chemotherapy that has increased in prevalence for the treatment of numerous malignancies. There are many rare complications from these medications that are sparsely reported. Knowledge of ocular hypotony as a potential consequence of nivolumab and ipilimumab is important, particularly as it may arise months after treatment initiation and necessitate immunotherapy cessation.

Eyedrop Instillation Techniques, Difficulties, and Currently Available Solutions: A Literature Review

Purpose

To review current eyedrop instillation techniques, common difficulties faced by patients instilling eyedrops, available eyedrop assistive devices, and patient education regarding eyedrop instillation.

Methods

PubMed, Embase, and Google Scholar were searched from conception until June 2022 for articles on eyedrop instillation difficulties, techniques, tools, and patient education.

Results

Instillation involves pulling down the lower eyelids and placing drops on the corneal surface or conjunctival fornix, followed by closing of the eyelids for about 1 min. Examples of techniques include eyelid closure and nasolacrimal obstruction techniques. Patients encounter many difficulties when administering eyedrops, including but not limited to poor visibility, squeezing the dropper bottle, aiming the bottle, and accidentally blinking. However, devices are available that assist with aim and dropper compression-force reduction in eyedrop instillation. These can be particularly useful in patient demographics with diminished manual dexterity or the ability to generate force from their fingers. Furthermore, despite patient education in eyedrop instillation not being a common practice, it has been found that adequate patient education can lead to significant improvement in eyedrop instillation technique.

Conclusions

While many factors are associated with poor eyedrop instillation technique, there are many solutions available including assistive devices and proper instillation education.

Medical student competence in ophthalmology assessed using the Objective Standardized Clinical Examination

Purpose

To assess pre-clerkship and clerkship medical student performance in an ophthalmology Objective Standardized Clinical Examination (OSCE) station.

Methods

One hundred pre-clerkship medical students and 98 clerkship medical students were included in this study. The OSCE station consisted of a common ocular complaint - blurry vision with decreased visual acuity - and students were asked to take an appropriate history, provide two or three differential diagnoses to explain the symptoms, and perform a basic ophthalmic examination.

Results

Generally, clerks performed better than pre-clerks in the history taking (P < 0.01) and ophthalmic examination (P < 0.05) sections, with few specific exceptions. In the history-taking section, more pre-clerkship students asked about patient age and past medical history (P < 0.00001) and for the ophthalmic examination, more pre-clerkship students performed the anterior segment examination (P < 0.01). Interestingly, more pre-clerkship students were also able to provide two or three differential diagnoses (P < 0.05), specifically diabetic retinopathy (P < 0.00001) and hypertensive retinopathy (P < 0.00001).

Conclusion

The performance of both groups was generally satisfactory; however, many students in both groups had scores that were unsatisfactory. Notably, pre-clerks also outperformed clerks in certain areas, which emphasizes the importance of revisiting ophthalmology content through clerkship. Awareness of such knowledge can allow medical educators to incorporate focused programs into the curriculum.

Globe Rupture Secondary to a Spontaneous Suprachoroidal Hemorrhage in a Blind Glaucomatous Eye: A Case Report

Purpose

To report a rare case of globe rupture following a spontaneous expulsive suprachoroidal hemorrhage without a predisposing event.

Methods

Case report.

Results

A 40-year-old man presented with a 3-week history of episodic eye pain, likely associated with uncontrolled glaucoma, and a spontaneous clot exuding from his right eye without a predisposing event. Notably, the patient had a remote past ocular history of posttraumatic glaucoma and untreated retinal detachment from childhood. He underwent uncomplicated evisceration of the right eye with polymethyl methacrylate implantation.

Conclusions

Spontaneous expulsive suprachoroidal hemorrhage without a predisposing event is an exceedingly rare phenomenon, with only six previously reported cases. It is possible that eyes with a history of trauma, possibly diseased eyewalls, and eyes with high intraocular pressure may be the most susceptible to spontaneous suprachoroidal hemorrhage and consequent globe rupture.

Safety and Efficacy of a Treat-and-Extend Regimen of Anti-Vascular Endothelial Growth Factor Agents for Diabetic Macular Edema or Macular Edema Secondary to Retinal Vein Occlusion: A Systematic Review and Meta-Analysis

[Box: see text] Background and Objective: This meta-analysis evaluates treat-and-extend regimens relative to monthly and as-needed (prn) regimens using anti-vascular endothelial growth factor agents for diabetic macular edema and macular edema secondary to retinal vein occlusion.

MATERIALS AND METHODS

Comparative studies evaluating a treat-and-extend regimen relative to a monthly or prn regimen with anti-vascular endothelial growth factor therapy for diabetic macular edema or macular edema secondary to retinal vein occlusion were included following a systematic literature search.

RESULTS

Seven studies of 984 eyes were included. Relative to a monthly regimen, treat-and-extend was similar for change in best-corrected visual acuity at final follow-up (P = .59) and had a lower number of injections (P < .00001). Relative to a prn regimen, treat-and-extend was similar for change in best-corrected visual acuity at final follow-up (P = .84) and was associated with a higher number of injections (P = .02).

CONCLUSION

This meta-analysis found that a treat-and extend regimen was nonsignificantly different compared to monthly and prn regimens in efficacy and safety end points. [Ophthalmic Surg Lasers Imaging Retina 2023;54(3):131-138.].

The Impact of Residual Retinal Fluid Following Intravitreal Anti-Vascular Endothelial Growth Factor Therapy for Diabetic Macular Edema and Macular Edema Secondary to Retinal Vein Occlusion: A Systematic Review

The association between residual retinal fluid and visual acuity for diabetic macular edema (DME) and macular edema (ME) secondary to retinal vein occlusion (RVO) is not well established. We conducted a systematic literature search for peer-reviewed articles reporting on visual acuity stratified by subretinal fluid (SRF), intraretinal fluid (IRF), or any retinal fluid at final follow-up after intravitreal anti-vascular endothelial growth factor therapy injection for treatment of DME or ME secondary to RVO. Two observational studies on ME secondary to RVO and one study for DME found no significant differences between eyes with and without residual retinal fluid for final BCVA. One randomized controlled trial (RCT) found that eyes with residual retinal fluid had significantly worse final best-corrected visual acuity in ME secondary to RVO, whereas another RCT found no significant difference for DME. There is a paucity of evidence examining the impact of residual retinal fluid on visual acuity in DME and ME secondary to RVO. The limited evidence suggests that aggressive fluid resolution is worthwhile. [Ophthalmic Surg Lasers Imaging Retina 2023;54:50-58.].

Anti-Vascular Endothelial Growth Factor Treatment Compared with Steroid Treatment for Retinal Vein Occlusion: A Meta-Analysis

BACKGROUND

Intravitreal anti-vascular endothelial growth factor (anti-VEGF) and steroid treatment are both used for macular edema (ME) secondary to retinal vein occlusion (RVO), however a continual reevaluation of their comparative efficacy is required.

OBJECTIVES

This meta-analysis aimed to compare the efficacy and safety of intravitreal anti-VEGF agents and intravitreal steroids for the treatment of ME secondary to RVO.

METHODS

A systematic literature search was conducted on Ovid MEDLINE, EMBASE, and the Cochrane Controlled Register of Trials for studies published between January 2005 and November 2021. Randomized controlled trials (RCTs) reporting on patients with ME secondary to RVO who were treated with intravitreal steroids or anti-VEGF agents were included. A random effects meta-analysis was performed.

RESULTS

879 eyes from 11 RCTs were included. At the last study observation, intravitreal anti-VEGF agents were associated with a significantly better best corrected visual acuity (WMD = -0.14 logMAR, 95% CI = [-0.19, -0.09], p < 0.00001) and lower retinal thickness (WMD = -38.01 µm, 95% CI = [-56.17, -19.85], p < 0.0001) relative to intravitreal steroids. Similar findings were found at 3-12 month time points. Intravitreal anti-VEGF agents were associated with a significantly lower incidence of IOP-related adverse events (RR = 0.28, 95% CI = [0.15, 0.51], p < 0.0001), cataract development/progression (RR = 0.22, 95% CI = [0.09, 0.49], p = 0.0003), and conjunctival hemorrhage (RR = 0.52, 95% CI = [0.32, 0.86], p = 0.01).

CONCLUSIONS

Our meta-analysis found superiority of intravitreal anti-VEGF agents relative to intravitreal steroids for the treatment of ME secondary to RVO with regards to visual acuity, anatomic outcomes, and safety endpoints.

RISK OF INTRAOCULAR INFLAMMATION AFTER INJECTION OF ANTIVASCULAR ENDOTHELIAL GROWTH FACTOR AGENTS: A Meta-analysis

PURPOSE

This meta-analysis investigates the incidence of intraocular inflammation (IOI) after intravitreal antivascular endothelial growth factor injections in neovascular age-related macular degeneration.

METHODS

A systematic search was performed on Ovid MEDLINE, Embase, and Cochrane Central from January 2005 to April 2021. Randomized controlled trials comparing IOI after intravitreal bevacizumab, ranibizumab, brolucizumab, or aflibercept in neovascular age-related macular degeneration were included. Primary outcomes were sight-threatening IOI, final best-corrected visual acuity, and change in best-corrected visual acuity from baseline. Secondary outcomes included the incidence of other IOI events. Meta-analysis was performed using a random-effects model.

RESULTS

Overall, 11,460 unique studies were screened, of which 14 randomized controlled trials and 6,759 eyes at baseline were included. There was no difference between agents for the risk of endophthalmitis and retinal vascular occlusion. Compared with aflibercept, brolucizumab had a higher incidence of generalized IOI (risk ratio = 6.24, 95% confidence interval = [1.40-27.90]) and vitreous haze/floaters (risk ratio = 1.64, 95% confidence interval = [1.00-2.67]). There were no significant differences between comparators for other secondary end points.

CONCLUSION

There was no difference in the risk of severe sight-threatening IOI outcomes between intravitreal antivascular endothelial growth factor agents. There was a significantly higher risk of generalized IOI after brolucizumab relative to aflibercept. Our results alongside other recent safety findings suggest the need for further investigation in the risk-benefit profile of brolucizumab for the treatment of neovascular age-related macular degeneration.

Intravitreal steroids compared to anti-vascular endothelial growth factor treatment for diabetic macular edema: a meta-analysis

TOPIC

Diabetic macular edema (DME) can be treated with either intravitreal anti-VEGF injections or intravitreal corticosteroid injections.

CLINICAL RELEVANCE

We provide an updated meta-analysis of the comparative efficacy and safety of intravitreal steroids and anti-VEGF agents for DME.

METHODS

A systematic search was performed on Ovid MEDLINE, Embase, and Cochrane Controlled Register of Trials from January 2005 to November 2021. Inclusion criteria included published randomized clinical trial data comparing the efficacy and safety of intravitreal steroids versus anti-VEGF agents for DME. Nonrandomized, noncomparative, and non-English studies were excluded.

RESULTS

Fourteen randomized clinical trials reporting on 827 eyes were included. Between these 2 treatments, our analysis revealed no significant difference in best-corrected visual acuity (BCVA) outcomes at 3 months (P = 0.11), 6 months (P = 0.21), 12 months (P = 0.24), and final follow-up (P = 0.91). Retinal thickness was significantly lower with steroid treatment at 3 months (P = 0.04), 6 months (P < 0.00001), and final follow-up (weighted mean difference = 39.99 μm; 95% confidence interval [CI] = 14.58,65.41; P = 0.002); however, there was no significant difference at 12 months (P = 0.18). Intravitreal anti-VEGF agents were associated with a lower incidence of intraocular pressure-related adverse events (risk ratio = 0.13; 95% CI = 0.05, 0.34; P < 0.00001). There was no significant difference between comparators for other adverse events, including cataract-related adverse events (P = 0.22).

CONCLUSIONS

Overall, intravitreal steroid treatment for DME was associated with no significant differences in BCVA, a significantly lower retinal thickness, and a higher risk of intraocular pressure-related events. The certainty of evidence ranged from low to moderate and the analysis was limited by heterogeneity. Our results reinforce the importance of a continual reevaluation of the role of intravitreal steroids in DME management.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Chemotherapy-Induced Toxicities: An Imaging Primer

The Coronavirus Disease of 2019 (COVID-19) pandemic has caused significant delays in the delivery of cancer treatments in Canada. As cancer treatment and imaging volumes return to normal, radiologists will encounter more cases of chemotherapy-induced toxicities. These toxicities have varied appearances on imaging, and can affect multiple organ systems. The purpose of this review is to offer a unified resource for general radiologists regarding the imaging appearances of chemotherapy-induced toxicities.

Association Between Visual Acuity and Residual Retinal Fluid Following Intravitreal Anti-Vascular Endothelial Growth Factor Treatment for Neovascular Age-Related Macular Degeneration: A Systematic Review and Meta-analysis

Importance

The association between residual subretinal fluid (SRF) and intraretinal fluid (IRF) and visual acuity following anti-vascular endothelial growth factor (VEGF) treatment is not well understood.

Objective

To examine the association of residual retinal fluid, SRF, and IRF with visual acuity following anti-VEGF treatment in patients with neovascular age-related macular degeneration (nAMD).

Data Sources

A systematic literature search was performed from January 2005 to August 2021 using Ovid MEDLINE, Embase, and the Cochrane Library.

Study Selection

Peer-reviewed articles reporting on visual acuity stratified by the presence or absence of any residual SRF, IRF, or any retinal fluid at last study observation after intravitreal bevacizumab, ranibizumab, aflibercept, or brolucizumab in patients with nAMD were included. Studies that were noncomparative, included fewer than 10 eyes, or reported on other anti-VEGF agents were excluded.

Data Extraction and Synthesis

Two independent reviewers conducted data extraction and synthesis. The Cochrane risk of bias tool 2 and ROBINS-I were used to assess risk of bias and GRADE evaluation was conducted to assess certainty of evidence.

Main Outcomes and Measures

Primary outcomes were BCVA at last study observation, change in BCVA from baseline, and retinal thickness at last study observation.

Results

In this systematic review and meta-analysis, 11 studies (6 randomized clinical trials [RCTs]) comprising 3092 eyes were included in our analysis. Across all included studies, the BCVA of eyes with residual SRF was better than eyes without SRF (weighted mean difference [WMD], 3.1 letter score; 95% CI, 0.05 to 6.18; P = .05; GRADE, low certainty of evidence; 6 studies; 1931 eyes) but similar in RCTs (WMD, 2.7 letter score; 95% CI, -2.40 to 7.84; P = .30; GRADE, low certainty of evidence; 3 studies; 1406 eyes). The BCVA of eyes with residual IRF was worse than that of eyes without IRF (WMD, -8.2 letter score; 95% CI, -11.79 to -4.50; P < .001; GRADE, low; 7 studies; 2114 eyes).

Conclusions and Relevance

The findings suggest that the presence of residual SRF was associated with slightly better BCVA at last study observation; however, baseline differences in BCVA existed and this conclusion was primarily driven by 1 study. The presence of residual IRF was associated with substantially worse BCVA at last study observation and less improvement of BCVA from baseline. The conclusions are limited by the inclusion of data from observational studies, heterogeneity, and a low certainty of evidence.

The Impact of the COVID-19 Pandemic on Radiology Resident Education: Where Do We Go From Here?

The Coronavirus Disease of 2019 (COVID-19) pandemic caused a dramatic shift in radiology resident education. Primarily, physical distancing prompted a general transition to virtual learning. Common changes made by radiology residency programs included virtual rounds and readouts, the use of simulation technology, and case-based learning which utilized pedagogical approaches such as the flipped classroom for teaching residents. Virtual learning appears to be a suitable alternative to traditional, in-person learning, and may have a place post-pandemic as part of a blended curriculum with in-person and virtual components. The extent of disruption to radiology resident education varied based on the local impact of COVID-19 and the prevalence of redeployment, as did residents’ mental health and wellbeing. Accessibility of mental health resources for residents was highlighted as an issue that programs need to address during these difficult times. Moreover, the pandemic resulted in unavoidable reductions in procedural exposure which programs mitigated through the use of simulation technologies and virtual learning resources. Professional development activities such as mentorship and career planning were also dramatically impacted by the pandemic and remains a challenge that programs need to consider moving forward post-pandemic. The purpose of this review is to outline the changes made to radiology resident education as a result of the COVID-19 pandemic and suggest what changes may be worthwhile to continue.

Conjunctival lymphangiectasia and retinal angiopathy in hereditary transthyretin amyloidosis

Background

Hereditary transthyretin amyloidosis (ATTR amyloidosis) is a rare condition where a mutation in the transthyretin gene leads to systemic deposition of amyloid. The manifestations and prognosis of ATTR amyloidosis depends on the specific ATTR mutation, with over 100 mutations reported in the literature. The manifestations of many rare forms of ATTR amyloidosis have not been well described, particularly the late-onset ophthalmic findings.

Case presentation

We present the case of a 43-year-old Caucasian male with a diagnosis of ATTRD18E amyloidosis confirmed by fat pad biopsy. He had diffuse systemic involvement, including cardiovascular, pulmonary, and gastrointestinal symptoms. He also had significant ocular involvement including vitreous opacities, retinal angiopathy, and conjunctival lymphangiectasia. These ocular findings modestly progressed at 2-year follow-up.

Discussion

The ATTRD18E mutation is a rare variant, with few described cases. To our knowledge, this is the first documented case of ATTRD18E amyloidosis with significant ocular involvement. These ocular findings may serve as a relevant biomarker for severe disease prognosis in ATTRD18E amyloidosis. With improving treatments addressing the systemic symptoms of ATTR amyloidosis, a better understanding of the late-onset ocular symptoms is becoming increasingly relevant.

1974. Ceftriaxone-Sulbactam-EDTA vs. Meropenem in PLEA (a Phase 3, Randomized, Double-Blind Trial): Outcomes by Baseline MIC in Adults With Complicated Urinary Tract Infections or Acute Pyelonephritis

Background

Ceftriaxone–sulbactam–disodium EDTA (CSE) is being developed for Gram-negative infections caused by multidrug-resistant (MDR) bacteria. PLEA was a Phase 3, double-blind, multicenter, randomized study of CSE vs. meropenem (MR) for treatment of adults with complicated urinary tract infections (cUTI) or acute pyelonephritis (AP). Non-inferiority of CSE over MR at the EMA/FDA primary endpoints has been reported. The effect of baseline MIC on clinical and microbiological outcome at the test of cure (TOC) visit was investigated.

Methods

Adult patients were randomized 1:1 to receive either CSE (1 g ceftriaxone/500 mg Sulbactam/37 mg EDTA) every 12 h or MR 1g every 8 hours as 30 minutes IV infusion for 5–14 days. Oral step-down therapy was not allowed. Prior to dosing, urine specimens were collected, and MICs were conducted using CLSI methods for both study drugs. Patients that were nonsusceptible to MR were not included in the mMITT population.

Results

Of 230 subjects randomized, 143 (62.2%) were included in the mMITT population. Baseline Enterobacteriaceae was found in 131 (91.6%) patients, 67/74 (90.5%) in CSE and 64/69 (92.8%) in MR arm. Mean duration of IV therapy was 7 days. Favorable clinical and microbiological outcomes were observed in ≥90% patients for all MICs across the two study groups, with the exception of MIC 1 μg/mL in MR (associated with >20% failures). Overall, both clinical cure and microbiological eradication rates were higher in CSE as compared with MR (95.9% Vs. 89.9% and 94.6% vs. 88.4% respectively) (Table 1).

Conclusion

CSE showed a high in vitro–in vivo correlation of >97% for MICs up to 4 μg/mL and is a potential new treatment option in patients with cUTI or AP.

Disclosures

P. Mandale, Venus Medicine Research Centre: Employee, Salary. M. A. Mir, Venus Medicine Research Centre: Employee, Salary. S. Chaudhary, Venus Medicine Research Centre: Employee and Shareholder, Salary. M. Chaudhary, Venus Medicine Research Centre: Board Member and Shareholder, Salary. A. Pyasi, Venus Medicine Research Centre: Employee, Salary.

1373. Activity of Ceftriaxone–Sulbactam–EDTA Against Multi-Drug-resistant A. baumannii, P. aeruginosa and Enterobacteriaceae Isolates (WHO Critical Priority Pathogens) Collected from Various Hospitals in India

Background

Ceftriaxone–Sulbactam–EDTA (CSE) is the first cephalosporin–β-lactamase inhibitor combination with an antibiotic resistance breaker–disodium edetate, recently evaluated in a Phase 3 clinical trial for treatment of adults with complicated urinary tract infections (NCT03477422). The addition of Sulbactam and EDTA expands the spectrum of activity of Ceftriaxone to include extended-spectrum-β-lactamase (ESBL) and metallo-β-lactamase (MBL) producing bacteria. This study evaluated the in vitro activity of CSE against 3,150 isolates (716 (22.73%) E. coli; 435 (13.81%) K. pneumoniae; 1,075 (34.13%) A. baumannii; 924 (29.33%) P. aeruginosa) collected from 22 hospitals in India during 2013–2016.

Methods

A total of 3,150 nonduplicate Gram-negative clinical isolates were collected, and susceptibility testing was conducted using reference broth microdilution method for CSE and comparators. CLSI defined phenotypic methods were used for ESBL and MBL detection, and thereafter, all isolates were further characterized genotypically using single PCRs and a panel of primers for detection of most β-lactamase enzymes, including blaTEM, blaSHV, blaCTX-M, blaAmpC, blaOXA, blaKPC, blaVIM, blaNDM, and blaIMP.

Results

Of the 3,150 isolates, 2,717 (86.25%) were β-lactamase producers, of which, 851 (31.32%) tested positive for ESBL, 1,591 (58.56%) tested positive for MBL, while 275 (10.12%) tested positive for both ESBL and MBL production during phenotypic evaluation. Once the genotype data were available, isolates were re-characterized as per the functional classification of β-lactamases into four distinct categories, including ESBL, AmpC, Carbapenemase and MBL. An astonishing 1,866 (59.23%) isolates harbored at least one MBL gene, of which, the prevalence was the highest in A. baumannii (78.6%), followed by K. pneumoniae (63%), P. aeruginosa (46.6%) and E. coli (44.1%). A summary of the results of susceptibility testing is shown in Figures 1, 2, and 3.

Conclusion

CSE showed a high overall susceptibility in ESBL- and MBL-producing bacteria and could provide a useful alternative to carbapenems and colistin in clinical settings.

Disclosures

R. Girotra, Venus Medicine Research Centre: Employee, Salary. A. Pyasi, Venus Medicine Research Centre: Employee, Salary. M. Chaudhary, Venus Medicine Research Centre: Board Member and Shareholder, Salary. M. A. Mir, Venus Medicine Research Centre: Employee, Salary. S. Chaudhary, Venus Medicine Research Centre: Employee and Shareholder, Salary. P. Mandale, Venus Medicine Research Centre: Employee, Salary.

1984. Ceftriaxone-Sulbactam-EDTA vs. Meropenem: Analysis of Failed Patients With Assessment of MIC Increases and Changes in Genotypic Profile in PLEA (a Phase 3, Randomized, Double-Blind Clinical Trial in Adults With Complicated Urinary Tract Infections or Acute Pyelonephritis)

Background

Ceftriaxone–sulbactam–EDTA (CSE) is a novel combination being developed to treat serious infections caused by Gram-negative bacteria. In vitro molecular biology studies have shown that the addition of EDTA in the combination helps to prevent horizontal gene transfer during conjugation by chelating the divalent magnesium ions (Mg²⁺) required for the activity of DNA relaxases enzyme. An assessment of acquisition of resistant genes and a concomitant increase in MIC for patients that failed therapy in the Phase 3 clinical trial (NCT03477422) was conducted.

Methods

MICs were conducted on baseline and post-treatment isolates recovered during treatment period. MICs were determined using CLSI reference methods and MIC changes from baseline were further assessed. Bacterial DNA was extracted by the alkaline lysis method. β-Lactamase (BL) genes were amplified in single PCRs using a panel of primers for detection of most β-lactamase enzymes, including extended-spectrum β-lactamases (ESBLs) (bla_TEM, bla_SHV, bla_CTX-M), metallo-β-lactamases (MBLs) (bla_VIM, bla_NDM, bla_IMP), carbapenemases (bla_OXA, bla_KPC) and class C cephalosporinases (bla_AmpC).

Results

Nine of 143 [2/74 (2.7%) in CSE; 7/69 (10.1%) in MR (meropenem)] patients had a microbiological failure at the TOC visit. Of these nine patients (all E. coli), a variation in the post-treatment genotypic profile was noted for four patients (44.4%) in the MR group and two of these patients also reported a ≥4-fold increase in post-treatment MIC. Both patients harbored four distinct BL genes (bla_TEM + bla_SHV + bla_CTX-M + bla_AmpC) at baseline, and had acquired two additional genes (bla_OXA, bla_KPC), both carbapenemases, as a result of treatment failure (after 6 days and 8 days of IV therapy respectively) with MR. In the first case, MIC increased 16-fold (1 µg/mL to 16 µg/mL for MR and 2 µg/mL to 32 µg/mL for CSE), while in the second case, MIC increased 8-fold (1 µg/mL to 8 µg/mL) for MR and 32-fold (1 µg/mL to 32 µg/mL) for CSE. No such increase in MIC or acquisition of resistant genes was noted in patients that failed therapy with CSE.

Conclusion

These findings highlight the need for an effective choice of empirical therapy as failed treatments could lead to selection for resistant genes, rendering once susceptible drug non-susceptible.

Disclosures

M. A. Mir, Venus Medicine Research Centre: Employee, Salary. S. Chaudhary, Venus Medicine Research Centre: Employee and Shareholder, Salary. M. Chaudhary, Venus Medicine Research Centre: Board Member and Shareholder, Salary. A. Pyasi, Venus Medicine Research Centre: Employee, Salary. R. Girotra, Venus Medicine Research Centre: Employee, Salary.

Rheumatoid arthritis (RA)-associated HLA-DR alleles form less stable complexes with class II-associated invariant chain peptide than non-RA-associated HLA-DR alleles

Certain HLA-DR alleles confer strong susceptibility to the autoimmune disease rheumatoid arthritis (RA). We compared RA-associated alleles, HLA-DR*0401, HLA-DR*0404, and HLA-DR*0405, with closely related, non-RA-associated alleles, HLA-DR*0402 and HLA-DR*0403, to determine whether they differ in their interactions with the class II chaperone, invariant chain (Ii). Ii binds to class II molecules in the endoplasmic reticulum, inhibits binding of other ligands, and directs class II-Ii complexes to endosomes, where Ii is degraded to class II-associated Ii peptide (CLIP). To evaluate the interaction of Ii and CLIP with these DR4 alleles, we introduced HLA-DR*0401, *0402, and *0404 alleles into a human B cell line that lacked endogenous HLA-DR or HLA-DM molecules. In a similar experiment, we introduced HLA-DR*0403 and *0405 into an HLA-DM-expressing B cell line, 8.1.6, and its DM-negative derivative, 9.5.3. Surface abundance of DR4-CLIP peptide complexes and their susceptibility to SDS-induced denaturation suggested that the different DR4-CLIP complexes had different stabilities. Pulse-chase experiments showed CLIP dissociated more rapidly from RA-associated DR molecules in B cell lines. In vitro assays using soluble rDR4 molecules showed that DR-CLIP complexes of DR*0401 and DR*0404 were less stable than complexes of DR*0402. Using CLIP peptide variants, we mapped the reduced CLIP interaction of RA-associated alleles to the shared epitope region. The reduced interaction of RA-associated HLA-DR4 molecules with CLIP may contribute to the pathophysiology of autoimmunity in RA.

Autoantigenic HCgp39 epitopes are presented by the HLA-DM-dependent presentation pathway in human B cells

It is hypothesized that autoimmune diseases manifest when tolerance to self-Ags fails. One possible mechanism to break tolerance is presentation of self-Ag in an altered form. Most Ags are presented by APCs via the traditional presentation pathway that includes "epitope editing" by intracellular HLA-DM, a molecule that selects for stable MHC-peptide complexes. We were interested in testing the hypothesis that autoreactive MHC-peptide complexes may reach the cell surface by an alternate pathway without being edited by HLA-DM. We selected a cartilage autoantigen human cartilage glycoprotein 39 to which T cell responses are observed in rheumatoid arthritis (RA) patients and some DR(*)04 healthy subjects. RA is genetically associated with certain DRB1 alleles, including DRB1(*)0401 but closely related allele DRB1(*)0402 is either neutral or mildly protective with respect to RA. We generated human B lymphoblastoid cell line cells expressing DR(*)0401 or DR(*)0402 in the presence or absence of intracellular HLA-DM and assessed their ability to present a candidate autoantigen, human cartilage glycoprotein 39. Our results show that the presence of intracellular HLA-DM is critical for presentation of this autoantigen to CD4(+) T cell hybridomas generated from DR(*)04-transgenic mice. Presentation of an autoantigen by the traditional HLA-DM-dependent pathway has implications for Ag presentation events in RA.

A developmentally regulated deletion element with long terminal repeats has cis-acting sequences in the flanking DNA

Approximately 6000 specific DNA deletion events occur during development of the somatic macro-nucleus of the ciliate Tetrahymena. The eliminated Tlr1 element is 13 kb or more in length and has an 825 bp inverted repeat near the rearrangement junctions. A functional analysis of the cis -acting sequences required for Tlr1 rearrangement was performed. A construct consisting of the entire inverted repeat and several hundred base pairs of flanking DNA on each side was rearranged accurately in vivo and displayed junctional variability similar to the chromosomal Tlr1 rearrangement. Thus, 11 kb or more of internal element DNA is not required in cis for DNA rearrangement. A second construct with only 51 bp of Tetra-hymena DNA flanking the right junction underwent aberrant rearrangement. Thus, a signal for determination of the Tlr1 junction is located in the flanking DNA, 51 bp or more from the right junction. Within the Tlr1 inverted repeat are 19 bp tandem repeats. A construct with the 19mer repeat region deleted from the right half of the inverted repeat utilized normal rearrangement junctions. Thus, despite its transposon-like structure, Tlr1 is similar to other DNA rearrangements in Tetrahymena in possessing cis -acting sequences outside the deleted DNA.

Accessory molecules for MHC class II peptide loading

Accessory molecules, such as HLA-DM and invariant chain, modulate the ligands bound to MHC class II molecules in antigen-presenting cells. Recent investigations, including gene targeting experiments, have shed light on the functions of these molecules, their mechanisms of action, interactions with class II molecules, and the relationships with associated molecules such as tetraspanins and HLA-DO.

Alternate junctions and microheterogeneity of Tlr1, a developmentally regulated DNA rearrangement in Tetrahymena thermophila

A large number of developmentally regulated DNA rearrangements occur during the development of the macronucleus in Tetrahymena thermophila. Tlr1 is a deletion element which has large inverted repeats near the rearrangement junctions and deletes more than 13 kbp of internal DNA. Previous analysis of caryonidal lines revealed alternate left junctions for the Tlr1 rearrangement in B strain cells. We show here that C2 strain Tetrahymena also use alternate rearrangement junctions. We have mapped and sequenced two additional rearrangement variants and find that both the left and right junctions can vary over a range of approximately 200 bp. We also demonstrate the presence of sequence microheterogeneity in the most commonly found Tlr1 rearrangement product.

Macroporous poly(sucrose acrylate) hydrogel for controlled release of macromolecules

We have studied the controlled release of proteins from poly(sucrose acrylate) hydrogels. The hydrogels were prepared by a two-step procedure in which sucrose was first acylated to sucrose-1'-acrylate followed by free radical polymerization. By adjusting the cross-link ratio and initial monomer concentration, the swelling ratio of the hydrogel was varied from five to 28. The mechanical strength of these hydrogels was comparable to that of the hydrogels with approximately the same swelling ratio. Scanning electron micrographs and mesh size calculations indicate that the hydrogel is macroporous, suggesting it may be suitable for a variety of biomedical applications. The release kinetics of beta-lactoglobulin, bovine serum albumin and gamma-globulin were studied as a function of initial monomer concentrations for the sucrose-based hydrogel. All of the release profiles were characterized by an initial burst of protein in the first 25 h followed by a long period of sustained release (> 500 h). The magnitude of the initial burst was reduced by increasing the initial monomer concentration and by increasing the molecular weight of the protein. A quantitative model based on the heterogeneous nature of hydrogel was developed to explain the observed release kinetics.

Adaptive larval thermotolerance and induced cross-tolerance to propoxur insecticide in mosquitoes Anopheles stephensi and Aedes aegypti

Fourth-instar larvae of mosquitoes Anopheles stephensi and Aedes aegypti normally died within 90 min at 43 degrees C. Pre-exposure to high but sublethal temperatures conferred adaptive thermotolerance, dependent on the temperature and the duration of pre-exposure. Adaptive cross-tolerance to propoxur (a carbamate insecticide) was also induced in larvae by pre-exposing them to sublethal temperatures. Pre-exposure to sublethal concentrations of propoxur was found to confer cross-thermotolerance to a lower extent. These results suggest that the shock proteins (e.g. heat shock proteins) induced by unrelated stress factors play an important role in the development of adaptive cross-protection (stress response) to other stress conditions.