Large-volume RT-LAMP enables extraction-free amplification of HIV RNA from fingerstick plasma.

BACKGROUND: Point-of-care (POC) nucleic acid amplification tests (NAAT) can significantly expand testing coverage, which is critical for infectious disease diagnostics and monitoring. The development of various isothermal amplification techniques greatly simplifies NAATs, but the cumbersome nucleic acid extraction step remains a bottleneck for the POC. Alternatively, extraction-free amplification, where crude samples are directly added into the assay, substantially simplifies the workflow. However, sample dilution is often needed in extraction-free amplification to reduce assay inhibition from sample matrices. Since NAATs are typically run at small volumes around 20 µL, the input sample quantity is therefore limited, resulting in an inevitable sensitivity loss. RESULTS: Here we explore the potential to perform isothermal amplification in larger reaction volumes to accommodate larger sample quantities, thereby improving sensitivity in extraction-free amplification. We demonstrated the approach by developing large-volume reverse transcription loop-mediated isothermal amplification (RT-LAMP) for HIV RNA detection from fingerstick plasma. We found that LAMP at reaction volumes up to 1 mL maintained the same performance. We then identified plasma dilution conditions needed to maintain the limit of detection in RT-LAMP. Subsequently, using inactivated HIV virus, we showed the successful detection of 24 HIV RNA copies in a 500 µL RT-LAMP reaction in the presence of 20 µL plasma (fingerstick volumes), translating to a viral load of 1200 copies per mL. To reduce the increased reagent cost with expanded reaction volumes, we further identified lower-cost reagents with maintained assay performance. Moreover, we showed that large-volume LAMP, compared to 20 µL reactions, could tolerate higher concentrations of various inhibitors in the sample, such as albumin and GuSCN. SIGNIFICANCE AND NOVELTY: NAATs are conventionally conducted at small reaction volumes. Here we demonstrated that LAMP can be run at large reaction volumes (over 100 µL) with maintained assay performance, allowing sample inhibition to be mitigated while accommodating larger sample quantities. The same strategy of expanding reaction volumes could be applied to other isothermal amplification methods and various POC applications, to streamline test workflows and/or improve assay sensitivity.

Living with your biome: how the bacterial microbiome impacts ocular surface health and disease.

Introduction: Microbiome research has grown exponentially but the ocular surface microbiome (OSM) remains an area in need of further study. This review aims to explore its complexity, disease-related microbial changes, and immune interactions, and highlights the potential for its manipulation as a therapeutic for ocular surface diseases. Areas Covered: We introduce the OSM by location and describe what constitutes a normal OSM. Second, we highlight aspects of the ocular immune system and discuss potential immune microbiome interactions in health and disease. Finally, we highlight how microbiome manipulation may have therapeutic potential for ocular surface diseases. Expert Opinion: The ocular surface microbiome varies across its different regions, with a core phyla identified, but with genus variability. A few studies have linked microbiome composition to diseases like dry eye but more research is needed, including examining microbiome interactions with the host. Studies have noted that manipulating the microbiome may impact disease presentation. As such, microbiome manipulation via diet, oral and topical pre and probiotics, and hygienic measures may provide new therapeutic algorithms in ocular surface diseases.

Combination Treatment of Biochanin A and Atorvastatin Alters Mitochondrial Bioenergetics, Modulating Cell Metabolism and Inducing Cell Cycle Arrest in Pancreatic Cancer Cells.

BACKGROUND/AIM: Pancreatic cancer is an aggressive type of cancer, with a dismally low survival rate of <5%. FDA-approved drugs like gemcitabine have shown little therapeutic success, prolonging survival by a mere six months. Isoflavones, such as biochanin A and daidzein, are known to exhibit anti-cancer activity, whereas statins reportedly have anti-proliferative effects. This study investigated the effects of combination treatment of biochanin A and atorvastatin on pancreatic cancer cells. MATERIALS AND METHODS: Pancreatic cancer cells AsPC-1, PANC-1, and MIA PaCa-2 were procured from ATCC. The cell viability studies were carried out using MTT & cell count assays. Flow cytometry was used to study cell apoptosis whereas cell metabolism studies were carried out using the Seahorse Mito stress test and XF-PMP assay. The effects of treatment on cell signaling pathways & cell cycle associated proteins were investigated using western blot whereas invasiveness of cancer cells was evaluated using gelatin zymography. RESULTS: The combination treatment decreased the survival and enhanced pro-apoptotic responses compared to single treatments in the pancreatic cancer cells. In PANC-1 cells, the combination treatment decreased invasiveness, reduced expression of activated STAT3 and expression of critical mediators of cell cycle progression. Furthermore, the combination treatment induced a differential inhibition of respiratory complexes in the pancreatic cancer cells. CONCLUSION: The combination treatment of biochanin A and atorvastatin exerts enhanced anti-cancer effects, inducing apoptosis, down-regulating cell cycle associated proteins and invasiveness in pancreatic cancer cells and merits further investigation for new, improved treatments for pancreatic cancer.

Impact of the geriatric emergency medicine specialist intervention on final emergency department disposition.

BACKGROUND: The Geriatric Emergency Medicine Specialist (GEMS) pilot program is an innovative approach that utilizes geriatric-trained advanced practice providers to facilitate geriatric assessments and care planning for older adults in the emergency department (ED). The objective of this study was to explore the effect of GEMS on the use of observation status and final ED disposition. METHODS: This was a retrospective study under a target trial emulation framework. Geriatric patients (65+ years old) who presented to two ED sites within a large regional healthcare system between December 2020 and December 2022 were included. The primary outcome was final ED disposition (discharge, hospital inpatient admission, or hospital observation admission). Secondary outcomes included ED observation and ED length of stay. Non-GEMS patients were propensity score matched 5:1 to GEMS patients. Doubly robust regression was used to estimate the odds ratios and 95% confidence intervals of inpatient admission, discharge, hospital observation admission, ED observation admission, and estimate the mean ED length of stay. RESULTS: A total of 427 of 43,064 total patients (1.0%) received a GEMS intervention during the study period. Our analysis included 2,302 geriatric ED patients (410 GEMS, 1,892 non-GEMS) after propensity score matching. Hospital admission rates were 34.1% for GEMS compared to 56.4% for conventional treatment. GEMS patients had decreased odds of inpatient admission (OR: 0.41, 95 CI: 0.34-0.51, p < 0.001), increased odds of discharge (OR: 1.19 95 CI: 1.00-1.42, p = 0.047), hospital observation admission (OR: 2.97, 95 CI: 2.35-3.75, p < 0.001), ED observation admission (OR: 4.84 95 CI: 3.67-6.38, p < 0.001), and had a longer average ED length of stay (170 min, 95 CI: 84.6-256, p < 0.001) compared to non-GEMS patients. CONCLUSIONS: Patients seen by GEMS during their ED visit were associated with higher rates of hospital discharge and lower rates of hospital admissions.

Sensitive Pathogen Detection and Drug Resistance Characterization Using Pathogen-Derived Enzyme Activity Amplified by LAMP or CRISPR-Cas.

Pathogens encapsulate or encode their own suite of enzymes to facilitate replication in the host. The pathogen-derived enzymes possess specialized activities that are essential for pathogen replication and have naturally been candidates for drug targets. Phenotypic assays detecting the activities of pathogen-derived enzymes and characterizing their inhibition under drugs offer an opportunity for pathogen detection, drug resistance testing for individual patients, and as a research tool for new drug development. Here, we used HIV as an example to develop assays targeting the reverse transcriptase (RT) enzyme encapsulated in HIV for sensitive detection and phenotypic characterization, with the potential for point-of-care (POC) applications. Specifically, we targeted the complementary (cDNA) generation activity of the HIV RT enzyme by adding engineered RNA as substrates for HIV RT enzyme to generate cDNA products, followed by cDNA amplification and detection facilitated by loop-mediated isothermal amplification (LAMP) or CRISPR-Cas systems. To guide the assay design, we first used qPCR to characterize the cDNA generation activity of HIV RT enzyme. In the LAMP-mediated Product-Amplified RT activity assay (LamPART), the cDNA generation and LAMP amplification were combined into one pot with novel assay designs. When coupled with direct immunocapture of HIV RT enzyme for sample preparation and endpoint lateral flow assays for detection, LamPART detected as few as 20 copies of HIV RT enzyme spiked into 25µL plasma (fingerstick volume), equivalent to a single virion. In the Cas-mediated Product-Amplified RT activity assay (CasPART), we tailored the substrate design to achieve a LoD of 2e4 copies (1.67fM) of HIV RT enzyme. Furthermore, with its phenotypic characterization capability, CasPART was used to characterize the inhibition of HIV RT enzyme under antiretroviral drugs and differentiate between wild-type and mutant HIV RT enzyme for potential phenotypic drug resistance testing. Moreover, the CasPART assay can be readily adapted to target the activity of other pathogen-derived enzymes. As a proof-of-concept, we successfully adapted CasPART to detect HIV integrase with a sensitivity of 83nM. We anticipate the developed approach of detecting enzyme activity with product amplification has the potential for a wide range of pathogen detection and phenotypic characterization.

Unveiling the Complex World of Extracellular Vesicles: Novel Characterization Techniques and Manufacturing Considerations.

Extracellular vesicles (EVs) function as potent mediators of intercellular communication for many in vivo processes, contributing to both health and disease related conditions. Given their biological origins and diverse functionality from correspondingly unique "cargo" compositions, both endogenous and modified EVs are garnering attention as promising therapeutic modalities and vehicles for targeted therapeutic delivery applications. Their diversity in composition, however, has revealed a significant need for more comprehensive analytical-based characterization methods, and manufacturing processes that are consistent and scalable. In this review, we explore the dynamic landscape of EV research and development efforts, ranging from novel isolation approaches, to their analytical assessment through novel characterization techniques, and to their production by industrial-scale manufacturing process considerations. Expanding the horizon of these topics to EVs for in-human applications, we underscore the need for stringent development and adherence to Good Manufacturing Practice (GMP) guidelines. Wherein, the intricate interplay of raw materials, production in bioreactors, and isolation practices, along with analytical assessments compliant with the Minimal Information for Studies of Extracellular Vesicles (MISEV) guidelines, in conjunction with reference standard materials, collectively pave the way for standardized and consistent GMP production processes.

Demographics, Practice Analysis, and Geographic Distribution of Neuro-Ophthalmologists in the United States in 2023.

PURPOSE: To assess the demographic characteristics and geographic distribution of neuro-ophthalmologists practicing in the United States. DESIGN: A cross-sectional study. PARTICIPANTS: Neuro-ophthalmologists across the United States. METHODS: In this cross-sectional study, public databases from the American Academy of Ophthalmology, North American Neuro-ophthalmology Society, American Neurological Association, and American Academy of Neurology were used to identify neuro-ophthalmologists in the United States as of April 2023. Providers' office locations were geocoded using ArcGIS pro, version 2.9 (Esri). Data on age, sex, and residency and fellowship training were collected. Analysis was performed using SPSS 28.0 (IBM Corp.). MAIN OUTCOME MEASURES: Neuro-ophthalmologists' demographics, and information about their medical education, postgraduate education, residency training, fellowship training, years in practice, practice environment, and geographic distribution of neuro-ophthalmologists across the United States. RESULTS: A total of 635 neuro-ophthalmologists (436 male, 68.7%) were identified. The majority (599, 94.3%) graduated from an allopathic medical school. Most of the 85 physicians who held a secondary graduate degree had a PhD (54, 63.5%). Although approximately three-quarters (429, 67.6%) completed their residency in ophthalmology, 159 (25%) had residency positions in neurology and 47 (7.4%) had residency positions in both. Approximately one-third (191, 30.0%) were trained in more than 1 fellowship, including oculoplastics (78, 12.3%) or pediatric ophthalmology (53, 8.3%). The average post-fellowship years of experience was 23.7±13.7 years, with 134 (21.1%) in their early career (< 10 years), 120 (18.9%) in their mid-careers (10-19 years), and 381 (60.0%) in their late careers (> 20 years). Male neuro-ophthalmologists had 10.5±1.1 more years of experience than female neuro-ophthalmologists (P < 0.001). Three states (Maine, South Dakota, Wyoming) and 2897 counties (93.2%) had no neuro-ophthalmologists. Counties without a neuro-ophthalmologist had lower median income (P < 0.001), lower access to a vehicle (P = 0.024), and lower rates of health insurance (P = 0.012). CONCLUSIONS: Practicing neuro-ophthalmologists are mostly male and often are trained in more than 1 subspecialty. More than half of the practicing neuro-ophthalmologists are in their late careers, which may further exacerbate the existing geographic and socioeconomic disparities in access to neuro-ophthalmology. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Lipids from ocular meibum and tears may serve as biomarkers for depression and post-traumatic stress disorder.

BACKGROUND: There is a need to develop biomarkers for diagnosis and prediction of treatment responses in depression and post-traumatic stress disorder (PTSD). METHODS: Cross-sectional study examining correlations between tear inflammatory proteins, meibum and tear sphingolipids, and symptoms of depression and PTSD-associated anxiety. Ninety individuals filled depression (Patient Health Questionnaire 9, PHQ-9) and PTSD-associated anxiety (PTSD Checklist-Military Version, PCL-M) questionnaires. In 40 patients, a multiplex assay system was used to quantify 23 inflammatory proteins in tears. In a separate group of 50 individuals, liquid chromatography-mass spectrometry was performed on meibum and tears to quantify 34 species of sphingolipids, encompassing ceramides, monohexosyl ceramides and sphingomyelins. RESULTS: The mean age of the population was 59.4 ± 11.0 years; 89.0% self-identified as male, 34.4% as White, 64.4% as Black, and 16.7% as Hispanic. The mean PHQ-9 score was 11.1 ± 7.6, and the mean PCL-M score was 44.3 ± 19.1. Symptoms of depression and PTSD-associated anxiety were highly correlated (ρ =0.75, p < 0.001). Both PHQ9 and PCL-M scores negatively correlated with multiple sphingolipid species in meibum and tears. In multivariable models, meibum Monohexosyl Ceramide 26:0 (pmol), tear Ceramide 16:0 (mol%), meibum Monohexosyl Ceramide 16:0 (mol%), and tear Ceramide 26:1 (mol%) remained associated with depression and meibum Monohexosyl Ceramide 16:0 (mol%), meibum Monohexosyl Ceramide 26:0 (pmol), tear Sphingomyelin 20:0 (mol%), and tear Sphingosine-1-Phosphate (mol%) remained associated with PTSD-associated anxiety. CONCLUSIONS: Certain meibum and tear sphingolipid species were related to mental health indices. These interactions present opportunities for innovative diagnostic and therapeutic approaches for mental health disorders.

Dementia risk analysis using temporal event modeling on a large real-world dataset.

The objective of the study is to identify healthcare events leading to a diagnosis of dementia from a large real-world dataset. This study uses a data-driven approach to identify temporally ordered pairs and trajectories of healthcare codes in the electronic health record (EHR). This allows for discovery of novel temporal risk factors leading to an outcome of interest that may otherwise be unobvious. We identified several known (Down syndrome RR = 116.1, thiamine deficiency RR = 76.1, and Parkinson's disease RR = 41.1) and unknown (Brief psychotic disorder RR = 68.6, Toxic effect of metals RR = 40.4, and Schizoaffective disorders RR = 40.0) factors for a specific dementia diagnosis. The associations with the greatest risk for any dementia diagnosis were found to be primarily related to mental health (Brief psychotic disorder RR = 266.5, Dissociative and conversion disorders RR = 169.8), or neurologic conditions or procedures (Dystonia RR = 121.9, Lumbar Puncture RR = 119.0). Trajectory and clustering analysis identified factors related to cerebrovascular disorders, as well as diagnoses which increase the risk of toxic imbalances. The results of this study have the ability to provide valuable insights into potential patient progression towards dementia and improve recognition of patients at risk for developing dementia.

Unexplained Vision Loss Associated With Intraocular Silicone Oil Tamponade in Rhegmatogenous Retinal Detachment Repair.

Purpose: To evaluate the visual outcomes with unexplained vision loss during or after silicone oil (SO) tamponade. Methods: This multicenter retrospective case series comprised patients with unexplained vision loss associated with SO tamponade or its removal. Eyes with other clear secondary identifiable causes of vision loss were excluded. Results: Twenty-nine eyes of 28 patients (64% male) were identified. The mean age was 50 ± 13 years (range, 13-78 years). The mean duration of SO tamponade was 148 ± 38 days. Eighteen eyes (62%) developed unexplained vision loss while under SO; 11 (38%) had vision loss after SO removal. The most common optical coherence tomography (OCT) finding was ganglion cell layer (GCL) thinning (55%). Eyes with vision loss after SO removal had a mean logMAR best-corrected visual acuity (BCVA) of 0.6 ± 0.7 (Snellen 20/85) before SO tamponade and 1.2 ± 0.4 (20/340) before SO removal. By the last follow-up after SO removal, the BCVA had improved to 1.1 ± 0.4 (20/235). In eyes with vision loss after SO removal, the BCVA before SO removal was 0.7 ± 0.7 (20/104), which deteriorated to 1.4 ± 0.4 (20/458) 1 month after SO removal. By the last follow-up, the BCVA had improved to 1.0 ± 0.5 (20/219). Conclusions: Unexplained vision loss can occur during SO tamponade or after SO removal. Vision loss was associated with 1000-centistoke and 5000-centistoke oil and occurred in macula-off and macula-on retinal detachments. The duration of tamponade was 3 months or longer in the majority of eyes. Most eyes had GCL thinning on OCT. Gradual visual recovery can occur yet is often incomplete.

Clinical Outcome of Cystoid Macular Edema in Silicone Oil-Filled Eyes.

Purpose: To investigate the clinical outcome of cystoid macular edema (CME) in eyes undergoing silicone oil (SO) tamponade with subsequent SO removal (SOR). Methods: A retrospective case series of adult patients with CME treated with SO tamponade and SOR was conducted between January 2015 and January 2021. Exclusion criteria included eyes with a prior SO tamponade, those that did not undergo SOR, or those with infectious/inflammatory diagnoses. The primary outcomes were the incidence and resolution rates of CME in eyes with SO tamponade that had undergone SOR. The secondary outcomes included changes in best-corrected visual acuity (BCVA) and central field thickness (CFT). Results: Nineteen eyes of 19 patients (58% men) aged 52 years (interquartile range [IQR], 45-66 years) met the study inclusion criteria. The median (IQR) follow-up duration post SOR was 22 (8-35) months. The mean CFT decline for the CME-resolved cases was 13.1 µm/mo (P = .257). CME resolved in only 10 eyes (53%), 7 (67%) of which occurred after SOR. The median (IQR) BCVA was 20/400 (20/200 to 20/1262) at CME diagnosis and 20/796 (20/252 to hand motions) after SOR, with 0.184 worsening in logMAR BCVA (P = .340). Medical treatment was not associated with CME resolution compared with observation (50% vs 89%, respectively; P = .069). Eyes with proliferative vitreoretinopathy (PVR) had a higher rate of persistent CME compared with eyes with other diagnoses (78% vs 10%, respectively; P = .005). Conclusions: Nearly half had nonresolution of CME after SO was removed. The VA at the last follow-up was unaffected by CME resolution. Preoperative PVR may be a risk factor for unresolved CME.

What Are Patients Asking Online About Strabismus? An Analysis of the Strabismus Subreddit.

BACKGROUND: Reddit is particularly popular due to its anonymity and discussion forum-type format. As an increasing number of patients seek medical advice on social media online, understanding patients' activity regarding strabismus on Reddit will help assess their concerns and guide patient education. METHODS: A cross-sectional study of Reddit posts (www.reddit.com/r/strabismus/) was conducted from July 2021 to July 2022. Posts were sorted by date, type, content, emotional tone, and users' sex and age (when available). RESULTS: A total of 709 posts were analyzed. Of the 164 (23%) posts in which users identified sex, 85 (52%) were female. The average age of patients to whom the post regarded was 23.7 ± 11.4 years (range 1-60 years). The most common content was surgical treatment (453, 63.9%), non-surgical treatment (263, 37%), seeking a diagnosis of their condition (190, 26.8%), and sharing personal journeys (136, 19.2%). Of the 289 (41%) posts that conveyed a clear emotional tone, the most common were anxiety (48, 18.3%), happiness (31, 11.8%), insecurity (24, 9.2%), frustration (22, 8.4%), and excitement (22, 8.4%). "Anxiety" posts had a significantly greater association with pre-surgery concerns whereas "happy" posts had a significantly greater association with post-operative updates (p = .003). CONCLUSIONS: Patients with strabismus who post on Reddit tend to be young adults interested in surgical treatment options. Although the pre-operative tone was anxiety, post-operative posts tended to be happy.

Natural Products and Small Molecules Targeting Cellular Ceramide Metabolism to Enhance Apoptosis in Cancer Cells.

Molecular targeting strategies have been used for years in order to control cancer progression and are often based on targeting various enzymes involved in metabolic pathways. Keeping this in mind, it is essential to determine the role of each enzyme in a particular metabolic pathway. In this review, we provide in-depth information on various enzymes such as ceramidase, sphingosine kinase, sphingomyelin synthase, dihydroceramide desaturase, and ceramide synthase which are associated with various types of cancers. We also discuss the physicochemical properties of well-studied inhibitors with natural product origins and their related structures in terms of these enzymes. Targeting ceramide metabolism exhibited promising mono- and combination therapies at preclinical stages in preventing cancer progression and cemented the significance of sphingolipid metabolism in cancer treatments. Targeting ceramide-metabolizing enzymes will help medicinal chemists design potent and selective small molecules for treating cancer progression at various levels.

A simple agglutination system for rapid antigen detection from large sample volumes with enhanced sensitivity.

Lateral flow assays (LFAs) provide a simple and quick option for diagnosis and are widely adopted for point-of-care or at-home tests. However, their sensitivity is often limited. Most LFAs only allow 50 µL samples while various sample types such as saliva could be collected in much larger volumes. Adapting LFAs to accommodate larger sample volumes can improve assay sensitivity by increasing the number of target analytes available for detection. Here, a simple agglutination system comprising biotinylated antibody (Ab) and streptavidin (SA) is presented. The Ab and SA agglutinate into large aggregates due to multiple biotins per Ab and multiple biotin binding sites per SA. Dynamic light scattering (DLS) measurements showed that the agglutinated aggregate could reach a diameter of over 0.5 µm and over 1.5 µm using poly-SA. Through both experiments and Monte Carlo modeling, we found that high valency and equivalent concentrations of the two aggregating components were critical for successful agglutination. The simple agglutination system enables antigen capture from large sample volumes with biotinylated Ab and a swift transition into aggregates that can be collected via filtration. Combining the agglutination system with conventional immunoassays, an agglutination assay is proposed that enables antigen detection from large sample volumes using an in-house 3D-printed device. As a proof-of-concept, we developed an agglutination assay targeting SARS-CoV-2 nucleocapsid antigen for COVID-19 diagnosis from saliva. The assay showed a 10-fold sensitivity enhancement when increasing sample volume from 50 µL to 2 mL, with a final limit of detection (LoD) of 10 pg mL-1 (∼250 fM). The assay was further validated in negative saliva spiked with gamma-irradiated SARS-CoV-2 and showed an LoD of 250 genome copies per µL. The proposed agglutination assay can be easily developed from existing LFAs to facilitate the processing of large sample volumes for improved sensitivity.

INTRAOCULAR INFLAMMATION INCIDENCE AFTER INTRAVITREAL BROLUCIZUMAB INJECTION FOR EXUDATIVE AGE-RELATED MACULAR DEGENERATION.

PURPOSE: We evaluated the clinical outcomes of intraocular inflammation (IOI) of eyes with neovascular age-related macular degeneration (AMD) injected with brolucizumab in our tertiary referral center. METHODS: A retrospective case series for which clinical records of all eyes that received intravitreal brolucizumab at Bascom Palmer Eye Institute between December 1, 2019, and April 1, 2021, were reviewed. RESULTS: There were 345 eyes of 278 patients who received 801 brolucizumab injections. IOI was detected in 16 eyes of 13 patients (4.6%). In those patients, baseline Logarithm of Minimu Angle of Resolution (logMAR) best-corrected visual acuity was 0.32 0.2 (20/42), while it was 0.58 0.3 (20/76) at IOI presentation. The mean number of injections among eyes experiencing IOI was 2.4, and the interval between the last brolucizumab injection and IOI presentation was 20 days. There was no known case of retinal vasculitis. Management of IOI included topical steroids in seven eyes (54%), topical and systemic steroids in five eyes (38%), and observation in one eye (8%). Best-corrected visual acuity returned to baseline and inflammation resolved in all eyes by the last follow-up examination. CONCLUSION: Intraocular inflammation after brolucizumab injection for neovascular AMD was not uncommon. Inflammation resolved in all eyes by the last follow-up visit.

Intraocular Lens Exchange: Indications, Comparative Outcomes by Technique, and Complications.

Purpose: To describe the indications, outcomes, and complications associated with intraocular lens (IOL) exchange. Patients and Methods: To determine the relative frequency of postoperative complications between techniques for all patients undergoing IOL exchange from May 1, 2014 through August 31, 2020. Results: IOL exchange was performed in 511 eyes of 489 patients (59.7% men; mean age: 67.0 ± 13.9 years, median time from cataract procedure to IOL exchange: 47.5 months). Mean uncorrected visual acuity significantly improved from 20/192 Snellen equivalent (logMAR 0.981) preoperatively to 20/61 (logMAR 0.487) at last follow-up (P < 0.001). Overall, 384 eyes (78.7%) met their desired refractive outcome within ±1.0 diopter (D). The most frequent complication was cystoid macular edema (CME) (n=39, 7.6%). Iris-sutured technique was associated with significantly greater frequency of subsequent IOL dislocation (10.3%) than 4-point scleral sutured (0%, P = 0.002), anterior chamber IOL (ACIOL, 1.5%, P = 0.01), and 2-point scleral sutured (0%, P = 0.03) techniques. Yamane scleral-fixation technique was associated with significantly greater frequency of developing IOL tilt (11.8%) than ACIOL (0%, P = 0.002), 4-point scleral sutured (1.1%, P = 0.01), 2-point scleral sutured (0%, P = 0.04), and iris-sutured (0%, P = 0.04) techniques. Conclusion: IOL exchange significantly improved uncorrected visual acuity and more than three-quarters of eyes met the refractive goal. Certain techniques were associated with complications, including subsequent dislocation associated with iris-sutured technique and IOL tilt associated with Yamane scleral-fixation technique. This information may help guide surgeons in deciding between procedural techniques for individual patients during IOL exchange preoperative planning.

Haptic Erosion Following Sutureless Scleral-fixated Intraocular Lens Placement.

PURPOSE: To describe the clinical features and visual outcomes of eyes with conjunctival haptic erosion after sutureless intrascleral (SIS) fixated intraocular lens (IOL) placement. DESIGN: Retrospective case series. SUBJECTS: Patients experiencing haptic erosion after SIS fixation between January 1, 2013, and March 1, 2022. METHODS: A multicenter, multisurgeon, retrospective review. MAIN OUTCOME MEASURES: Clinical features, visual outcomes, and treatment options following haptic erosions after SIS fixation. RESULTS: Nineteen eyes with haptic erosion were identified. The mean age at initial SIS fixation was 64 ± 12 years (range, 38-81 years). There were 5 (26%) eyes with a history of conjunctiva involving ocular surgery, including scleral buckle surgery and tube shunt surgery. Trocar-assisted fixation was performed in 15 (79%) eyes, whereas needle fixation was used in 4 (21%) eyes. Eighteen (95%) sets of haptics were flanged with a low temperature cautery. Seventeen (90%) sets of haptics were externalized superiorly and inferiorly, and 2 (10%) sets of haptics were externalized nasally and temporally. Haptics were covered by conjunctiva in 14 (74%) eyes and by scleral flap in 5 (26%) eyes. All patients experienced a single haptic erosion, of which 8 (43%) were located superiorly, 9 (47%) inferiorly, and 2 (10%) temporally. The mean interval between the initial SIS fixation and haptic erosion was 278 ± 437 days. After correction of the erosion, 18 (95%) eyes had a stable IOL at the last follow-up, with no recurrence of haptic erosion. In this series, there were no cases of endophthalmitis. CONCLUSIONS: Haptic erosion is a notable complication after SIS fixated IOL surgery but may be repaired with favorable visual outcomes. Careful evaluation of the conjunctiva should be considered before the surgery. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Co-Culturing Rat Dorsal Root Ganglion Neurons With Rat Schwann Cells Protects Them Against the Cytotoxic Effects of Silver and Gold Nanoparticles.

Previous studies using monotypic nerve cell cultures have shown that nanoparticles induced neurotoxic effects on nerve cells. Interactions between neurons and Schwann cells may protect against the neurotoxicity of nanoparticles. In this study, we developed a co-culture model consisting of immortalized rat dorsal root ganglion (DRG) neurons and rat Schwann cells and employed it to investigate our hypothesis that co-culturing DRG neurons with Schwann cells imparts protection on them against neurotoxicity induced by silver or gold nanoparticles. Our results indicated that neurons survived better in co-cultures when they were exposed to these nanoparticles at the higher concentrations compared to when they were exposed to these nanoparticles at the same concentrations in monotypic cultures. Synapsin I expression was increased in DRG neurons when they were co-cultured with Schwann cells and treated with or without nanoparticles. Glial fibrillary acidic protein (GFAP) expression was increased in Schwann cells when they were co-cultured with DRG neurons and treated with nanoparticles. Furthermore, we found co-culturing with Schwann cells stimulated neurofilament polymerization in DRG neurons and produced the morphological differentiation. Silver nanoparticles induced morphological disorganization in monotypic cultures. However, there were more cells displaying normal morphology in co-cultures than in monotypic cultures. All of these results suggested that co-culturing DRG neurons with Schwann cells imparted some protection on them against neurotoxicity induced by silver or gold nanoparticles, and altering the expression of neurofilament-L, synapsin I, and GFAP could account for the phenomenon of protection in co-cultures.