Corneal Hysteresis as a Marker for Patients with Secondary Glaucoma

PURPOSE

To investigate and compare the association of corneal hysteresis (CH) in patients with secondary glaucoma to control patients and patients with primary open-angle glaucoma (POAG). Additionally, to determine the consistency of CH measurements in patients with secondary glaucoma.

METHODS

A total of 84 patients (121 eyes) were prospectively included in this study. Twenty-three patients (46 eyes) were healthy controls, 24 patients (40 eyes) were diagnosed with POAG, and 27 patients (35 eyes) were diagnosed with a form of secondary glaucoma. CH and intraocular pressure (IOP) were measured using the Ocular Response Analyzer. Three measurements per eye were performed and used for the analysis and to determine fluctuations in CH data. One-way ANOVA with post-hoc Bonferroni analysis and Chi-Squared testing was done to determine differences between groups.

RESULTS

All patients were matched for age. Patients in both POAG and secondary glaucoma groups were matched for age and IOP. All groups had similar sex and racial compositions as well as similar proportions of diabetes, hypertension, and hyperlipidemia. CH was lower (p < .05) in patients with POAG (9.32 ± 1.64) and secondary glaucoma (7.89 ± 3.18) when compared to healthy controls (11.16 ± 1.60). Fluctuations in CH measurements were minimal in all groups. Further analysis of the secondary glaucoma group revealed no differences in CH between different types of secondary glaucoma (p > .05).

CONCLUSION

Patients with secondary glaucoma have lower CH when compared to POAG or control groups. The ORA exhibits precision of CH measurements for control, POAG, and secondary glaucoma groups, making it a reliable tool in management of secondary forms of glaucoma.

Comparison of Efficacy of Micropulse and Continuous Wave Cyclophotocoagulation in Patients With Pediatric Glaucoma

PRCIS

Both micropulse (MP-CPC) and continuous wave (CW-CPC) cyclophotocoagulation exhibited short-term effectiveness in lowering IOP, followed by reversion to near baseline levels 12 months after laser treatment.

OBJECTIVE

To determine and compare the effectiveness and safety of MP-CPC and CW-CPC in patients diagnosed with pediatric glaucoma.

METHODS

A retrospective cohort study was conducted on a total of 28 patients (81 eyes) diagnosed with pediatric glaucoma either undergoing MP-CPC or CW-CPC. Intraocular pressure (IOP) measurements, number of glaucoma medications, and the onset of complications were collected at baseline, 1-month, 3-month, 6-month, and 12-month intervals. Success rate (SR) was defined as eyes achieving IOP ≤21 mm Hg and ≥5 mm Hg and a 20% reduction in IOP at the last follow-up visit.

RESULTS

All patients either undergoing MP-CPC or CW-CPC were matched for age (mean ± SD; 1.76 ± 1.69 vs 1.56 ± 2.49 y). Patients undergoing MP-CPC had significant decreases in IOP from baseline IOP at 1, 3, and 6 months with a 22% SR at 12 months. CW-CPC had a significant decrease in IOP from baseline IOP at all follow-ups, with a 27% SR at 12 months. At the 12-month follow-up, the CW-CPC cohort exhibited a significantly larger overall drop in IOP when compared with the MP-CPC cohort, (7.99 ± 7.95 vs 1.78 ± 6.89, P < 0.05); however, the difference in SR between treatment groups (27% vs 22%) at 12 months was not significant ( P > 0.05). Complications were minimal for both groups.

CONCLUSION

Both MP-CPC and CW-CPC exhibited short-term effectiveness in lowering IOP, followed by reversion to near baseline levels 12 months after laser treatment. Both MP-CPC and CW-CPC exhibited similar SR at 12 months, 22% and 27% respectively.

Clinical Report of the Effectiveness of Netasurdil in Patients with Uveitic Glaucoma

The use of netasurdil 0.02% (Rhopressa) in patients with primary open-angle glaucoma has been shown to be effective in lowering intraocular pressure (IOP). However, the effectiveness of netasurdil in patients with secondary forms of glaucoma has been minimally investigated. Previous reports have suggested its adequacy in lowering IOP in patients with congenital glaucoma. Its effectiveness in treating uveitic glaucoma, on the other hand, has yet to be formally examined. In a small group of patients with uveitic glaucoma, netasurdil has been shown to lower IOP by an average of 10.0mmHg, with over half of patients exhibiting more than a 20% decrease in IOP after 12 months of treatment. No patients developed any serious complications from taking netasurdil, however, conjunctival hyperemia was present in 15% of the patient population. Early success of netasurdil in patients with uveitic glaucoma warrants further investigation to better understand its safety and effectiveness.

Bibliometric Analysis of the Top 100 Cited Articles in Pediatric Ophthalmology

PURPOSE

To determine and analyze the 100 most cited articles in pediatric ophthalmology.

METHODS

A literature search was conducted using the ISI Web of Science database on the top 100 most cited articles in pediatric ophthalmology.

RESULTS

The 100 most cited articles were published between 1941 and 2018, with the greatest number published in both 2005 and 2012. A total of 29,731 citations were generated during the study period. There has been a significant increase in citations annually since 1941, with a peak number of citations in 2021 with 2,629 citations. Myopia, retinopathy of prematurity, and other forms of refractive error were the topics most studied and cited in these articles. Most of the articles were classified as either large cohort prospective/retrospective studies (34) or randomized clinical trials (19), with case reports/series being the least frequent (7). Investigative Ophthalmology & Visual Science (23), JAMA Ophthalmology (22), and Ophthalmology (22) published the majority of the articles. Institutions that conducted the majority of the studies presented include the National Eye Institute (10), the Ohio State University College of Optometry (9), and the Oregon Health & Science University (6).

CONCLUSIONS

This bibliometric analysis provides a unique historical perspective of the literature in the field of pediatric ophthalmology that has not been studied before. The research in the field of pediatric ophthalmology is advancing quickly, with most articles and citations occurring within the past 15 years. The strong focus on prospective cohort studies and clinical trials reveals the importance of advancing the treatment of critical disease within the field of pediatric ophthalmology. [J Pediatr Ophthalmol Strabismus. 2023;60(5):330-336.].

A Prospective Cohort Study on the Respiratory Effect on Modified Mallampati Scoring

Background

Mallampati scoring is a common exam method for evaluating the oropharynx as a part of the airway assessment and for anticipation of difficult intubation. It partitions the oropharynx into 4 categories with scores of 1, 2, 3, and 4. Even though its reliability is known to be limited by confounding factors such as patient positioning, patient phonation, tongue protrusion, and examiner variability, the effect of respiration, i.e., inspiration and expiration, has not yet been formally studied.

Methods

Mallampati scores were collected from 100 surgical patients during both inspiration and expiration and later compared to the score obtained in the medical record, determined by a board certified anesthesiologist.

Results

Score deviations from the medical record reference were compared for both inspiration and expiration showing that respiration affects Mallampati scores; for some patients, the scores improved (i.e., decreased), while in others they worsened (i.e., increased). The respiratory change effect was quantified and visualized by plotting the area under the curve of the histogram of the deviations. 42% of the patients had a worsening of scores by 1 or 2 points with inspiration while 36% of the patients had a worsening of scores by 1 or 2 points with expiration.

Conclusions

Mallampati scoring is commonly used in evaluating the oropharynx as a part of the airway assessment and as a screening tool for difficult intubations. However, as this study points out, the respiratory cycle substantially affects the Mallampati scoring system, with significant deviations of 1 or 2 points. In a scoring system of 4 score categories, these deviations are remarkable.

Microbiota Mediate Enhanced Exercise Capacity Induced by Exercise Training

PURPOSE

We investigated the effects of gut microbes, and the mechanisms mediating the enhanced exercise performance induced by exercise training, i.e., skeletal muscle blood flow, and mitochondrial biogenesis and oxidative function in male mice.

METHODS

All mice received a graded exercise test before (PRE) and after exercise training via forced treadmill running at 60% to 70% of maximal running capacity 5 d·wk -1 for 5 wk (POST). To examine the role of the gut microbes, the graded exercise was repeated after 7 d of access to antibiotic (ABX)-treated water, used to eliminate gut microbes. Peripheral blood flow, mitochondrial oxidative capacity, and markers of mitochondrial biogenesis were collected at each time point.

RESULTS

Exercise training led to increases of 60% ± 13% in maximal running distance and 63% ± 11% work to exhaustion ( P < 0.001). These increases were abolished after ABX ( P < 0.001). Exercise training increased hindlimb blood flow and markers of mitochondrial biogenesis and oxidative function, including AMP-activated protein kinase, sirtuin-1, PGC-1α citrate synthase, complex IV, and nitric oxide, all of which were also abolished by ABX treatment.

CONCLUSIONS

Our results support the concept that gut microbiota mediate enhanced exercise capacity after exercise training and the mechanisms responsible, i.e., hindlimb blood flow, mitochondrial biogenesis, and metabolic profile. Finally, results of this study emphasize the need to fully examine the impact of prescribing ABX to athletes during their training regimens and how this may affect their performance.

Epidemiological Trends of Ocular Injuries in Infants

Approximately 21,000 consumer product-related ocular injuries occurred in infants in the United States from 2009 to 2019; toys being the most common (12.9%) consumer product in the 1- to 4-month age cohort, detergents in the 5- to 8-month (21.6%) cohort, and chemicals for the 9- to 12-month (34.0%) age cohort. These results identify an important preventable consumer product-related public health problem in infants. [J Pediatr Ophthalmol Strabismus. 2023;60(4):e41-e44.].

Effectiveness of netarsudil 0.02% in lowering intraocular pressure in patients with secondary glaucoma

PURPOSE

To determine the effectiveness of netarsudil, 0.02% in lowering intraocular pressure (IOP) in patients with secondary forms of glaucoma.

METHODS

A total of 77 patients (98 eyes) with either primary open-angle glaucoma (POAG) or secondary glaucoma were reviewed retrospectively over the course of 1 year after starting netarsudil. The secondary glaucoma group was comprised of patients with uveitic, pseudoexfoliative, neovascular, congenital, and other forms of secondary glaucoma. Patient IOP measurements were collected at baseline and at 1-, 3-, 6-, and 12-month intervals. Two sample t tests and 1-way analysis of variance were used to determine differences in IOP reductions following netarsudil treatment.

RESULTS

Patients with POAG or secondary glaucomas were matched for age (mean ± SD: 69.1 ± 16.0 years vs. 64.5 ± 21.2 years; p = 0.30). Both the POAG and secondary glaucoma patients exhibited significant decreases in IOP at each time point (1, 3, 6, and 12 months) when compared with baseline (p < 0.05). Both groups showed similar overall decreases in IOP from baseline after 1 year of treatment (6.0 ± 4.5 mm Hg vs. 6.6 ± 8.4 mm Hg; p = 0.70). Forty-sex percent of POAG patients achieved an IOP of <14 mm Hg compared with 17% of secondary glaucoma patients. Among the secondary glaucoma subtypes, netarsudil was found to be most effective for treating uveitic glaucoma, showing a decrease in IOP of 9.5 mm Hg after 12 months (p = 0.02).

CONCLUSION

Netarsudil is effective in lowering IOP in patients with certain forms of secondary glaucoma and should be considered for IOP management in those with uveitic glaucoma.

Exercise enhancement by RGS14 disruption is mediated by brown adipose tissue

Enhanced exercise capacity is not only a feature of healthful aging, but also a therapy for aging patients and patients with cardiovascular disease. Disruption of the Regulator of G Protein Signaling 14 (RGS14) in mice extends healthful lifespan, mediated by increased brown adipose tissue (BAT). Accordingly, we determined whether RGS14 knockout (KO) mice exhibit enhanced exercise capacity and the role of BAT in mediating exercise capacity. Exercise was performed on a treadmill and exercise capacity was assessed by maximal running distance and work to exhaustion. Exercise capacity was measured in RGS14 KO mice and their wild types (WT), and also in WT mice with BAT transplantation from RGS14 KO mice or from other WT mice. RGS14 KO mice demonstrated 160 ± 9% increased maximal running distance and 154 ± 6% increased work to exhaustion, compared to WT mice. RGS14 KO BAT transplantation to WT mice, resulted in a reversal of phenotype, with the WT mice receiving the BAT transplant from RGS14 KO mice demonstrating 151 ± 5% increased maximal running distance and 158 ± 7% increased work to exhaustion, at three days after BAT transplantation, compared to RGS14 KO donors. BAT transplantation from WT to WT mice also resulted in increased exercise performance, but not at 3 days, but only at 8 weeks after transplantation. The BAT induced enhanced exercise capacity was mediated by (1) mitochondrial biogenesis and SIRT3; (2) antioxidant defense and the MEK/ERK pathway, and increased hindlimb perfusion. Thus, BAT mediates enhanced exercise capacity, a mechanism more powerful with RGS14 disruption.

A Comprehensive Evaluation of the Quality, Readability, and Technical Quality of Online Information on Glaucoma

PURPOSE

To evaluate the quality and reliability of medical information, the technical quality of the presentation of information, and the readability of informational websites that publish content on the definition, causes, symptoms, and treatment of glaucoma.

DESIGN

A cross-sectional study was conducted to assess information published on websites with regard to glaucoma.

SUBJECTS

The top 150 websites populated on a Google search using the keywords glaucoma, high intraocular pressure, and high eye pressure were chosen for evaluation.

METHODS

Two independent reviewers assessed quality and reliability of each website using the DISCERN, Health on the Net Code (HONcode), and Journal of the American Medical Association (JAMA) criteria. The reviewers also evaluated technical quality by determining each website's ability to satisfy 10 unique features. Readability was assessed using the Readability Studio software (Oleander Software).

MAIN OUTCOME MEASURES

Quality of information was analyzed using the DISCERN, HONcode, and JAMA criteria. To assess readability, the Bormuth Cloze Mean, Bormuth Grade Placement, Flesch Kincaid Reading Ease, Coleman-Liau Index, Gunning Fog Score, Simple Measure of Gobbledygook Index, Readability Score, Fry Estimate, Raygor Estimate, and the Overall Mean Readability metrics were used. A separate subanalysis categorized websites into institutional and private categories.

RESULTS

Readability was poor among all websites, with most websites requiring a reading level higher than the 11th grade. The overall mean DISCERN score ± standard deviation (SD) was 3.0 ± 0.4, the mean HONcode score ± SD was 9.6 ± 1.8, and the mean JAMA score ± SD was 2.1 ± 1.1. The reviewers had moderate to excellent interrater reliability. Institutional websites (n = 39) had a higher mean DISCERN score (3.18 ± 0.33 vs. 2.95 ± 0.39, P < 0.05) and mean HONcode score (10.18 ± 1.90 vs. 9.34 ± 1.71, P < 0.05) than those of private websites (n = 111). Technical quality was higher among institutional websites (P < 0.05).

CONCLUSIONS

An overwhelming majority of websites presented information of low quality, reliability, and readability. Institutional websites generally received higher scores than those received by private websites; however, overall scores were still substandard, which necessitates improvement of online information on glaucoma.

An Analysis of the Quality, Reliability, and Popularity of YouTube Videos on Glaucoma

PURPOSE

To evaluate the quality, reliability, and popularity of videos relating to glaucoma on YouTube.

DESIGN

Retrospective, cross-sectional study of YouTube videos about glaucoma.

PARTICIPANTS

One hundred YouTube videos were analyzed for this study.

METHODS

An online YouTube search for glaucoma videos was conducted simulating a user search using the keywords glaucoma, high eye pressure, and high intraocular pressure. The first 100 videos were analyzed, and each video was evaluated by 2 independent reviewers using the modified DISCERN (scale, 1-5), Journal of the American Medical Association (JAMA; scale, 0-4), and Global Quality (GQ; scale, 1-5) criteria to assess quality and reliability. Videos were categorized further into 3 groups depending on the source of their upload. Group 1 comprised videos uploaded by academic or government institutions, group 2 comprised videos uploaded by private medical practices, and group 3 comprised videos uploaded by independent users.

MAIN OUTCOME MEASURES

Modified DISCERN, JAMA, and GQ scores for quality and reliability of information and video power index (VPI) for video popularity.

RESULTS

No substantial difference in scoring was observed between the 2 independent reviewers. The overall mean ± standard error (SE) scores were modified DISCERN score, 3.81 ± 0.06; JAMA score, 2.93 ± 0.07; and GQ score, 3.98 ± 0.06. The overall mean ± SE VPI score was 9.9 ± 2.9. Significant positive correlations were found between video popularity and quality of information for all 3 criteria (P < 0.05). The videos in groups 1 and 2 showed higher modified DISCERN scores than those in group 3, but did not score higher with either the JAMA or GQ criteria. Videos in group 3 were the most popular when compared with videos in groups 1 or 2 (P < 0.01).

CONCLUSIONS

Overall, many of the videos had adequate quality and reliability scores. No difference was found among groups 1 through 3 for 2 of the 3 criteria used, suggesting a similar quality of information provided among academic, private, and independent sources.

Epidemiology of Ocular Injuries Related to Toy Guns in Pediatric Patients From 2000 to 2019

The popularity of toy guns among children is a growing public health concern due to reports of ocular injury. Most ocular injuries caused by toy guns occur in children younger than 10 years and at home. Dissemination of this information to parents and pediatricians is important to formulate safety measures. [J Pediatr Ophthalmol Strabismus. 2022;59(3):e29-e31.].

Aluminum Leaching from Fluid Warmers: Regulatory Deferral to Clinicians' Decision

Fluid-warming systems are crucial in surgical and trauma settings because of their key role in preventing or treating hypothermia and enabling proper resuscitation of blood products that are stored cold. Recently, several manufacturers have issued warnings of the possibility of aluminum leaching from their fluid warmers and cautioned about the potential for aluminum toxicity in patients who underwent fluid resuscitation with these devices. Studies suggest that one of the main factors affecting aluminum leaching in this setting is the coating of the aluminum plate itself. Coating, often with a biocompatible material, appears to reduce aluminum leaching by 100- to 200-fold compared with an uncoated plate. Nonetheless, leaching with the coating is still at a level exceeding U.S. regulations. A few aluminum-free warming systems are available on the market, but these are not carried by all providers and some clinicians may be less familiar with their use. Medical device manufacturers will likely design future warming systems with less potential for aluminum blood contact. In the meantime, the risk of inadequate resuscitation, consequent to the proper fluid warmer no longer being available, is contrasted with the risk of potential toxicity. In the situation described here, the regulators deferred the ultimate decision of which fluid warmer to use in a given situation to the risk-benefit decision of the clinician.

Appositional Choroidal Detachment Following XEN45 Gel Stent Requiring Surgical Drainage

An 82-year-old man with severe primary open-angle glaucoma on maximal medical therapy underwent an ab externo closed conjunctival Xen45 device insertion with mitomycin C. The surgery was uncomplicated, with a first postoperative day intraocular pressure of 4 mm Hg and visual acuity of 20/40 OD. Ten days later, the patient presented with an intraocular pressure of 5 mm Hg and a visual acuity of counting fingers at 5 feet. Examination showed Seidel negative bleb, shallow anterior chamber, and large nonappositional choroidal detachments. Medical therapy with steroids and cycloplegia was initiated. One week later, the serous choroidal detachments became appositional, and Xen explantation and surgical drainage of the choroidal detachment was performed. Postoperatively, the vision improved to 20/60. Significant choroidal detachments can occur after XEN45 implantation requiring surgical intervention.

Detection of Elder Abuse Among Orthopedic Patients

Approximately 10% of US adults experience elder abuse, which often manifests as musculoskeletal and soft tissue injuries. The goal of our study was to determine the rate of elder abuse among orthopedic surgery patients and characterize which patients may be at an increased risk. National Inpatient Sample Healthcare Cost and Utilization Project data from 2001 to 2015 were parsed with the Clinical Classifications Software tool. Patients 60 years and older were identified by International Classification of Diseases, Ninth Revision (ICD-9), code for elder abuse. Primary orthopedic procedures and subsequent inpatient diagnoses and comorbidities were used to develop a binary logistic regression model to predict an elder's risk of abuse. Of a total of 20,532,211 admissions for an orthopedic procedure, 0.010% (2084) were classified as elder abuse. Patients with a classification of abuse more commonly were women (74.8% vs 60.6%) and from the lowest socioeconomic quartile by income (28.5% vs 21.7%). In addition, these patients had hospital stays that were twice as long (10.2 vs 5.3 days) and had higher admission mortality rates (4.4% vs 1.2%). No primary orthopedic procedures were associated with a higher risk of elder abuse. Nonorthopedic diagnoses made during admission that were associated with increased risk of abuse included superficial injury or contusion (odds ratio [OR], 3.252), chronic skin ulcer (OR, 3.119), nutritional deficiency (OR, 3.418), fluid and electrolyte disturbances (OR, 1.729), and delirium or dementia (OR, 2.210). The incidence of elder abuse among orthopedic surgery patients is significantly lower than national estimates. This finding warrants further investigation to determine whether it is a function of underreporting or differences in patient populations, given the 4-fold increase in mortality risk. [Orthopedics. 2022;45(1):50-56.].

Quality Fade in Medical Device Manufacturing: Thinness of Airway Breathing Circuit Plastic

Mechanical respirators typically use a plastic circuit apparatus to pass gases from the ventilator to the patient. Structural integrity of these circuits is crucial for maintaining oxygenation. Anesthesiologists, respiratory therapists, and other critical care professionals rely on the circuit to be free of defects. The American Society for Testing and Materials maintains standards of medical devices and had a standard (titled Standard Specification for Anesthesia Breathing Tubes) that included circuits. This standard, which was last updated in 2008, has since been withdrawn. Lack of a defined standard can invite quality fade-the phenomenon whereby manufacturers deliberately but surreptitiously reduce material quality to widen profit margins. With plastics, this is often in the form of thinner material. A minimum thickness delineated in the breathing circuit standard would help ensure product quality, maintain tolerance to mechanical insults, and avert leaks. Our impression is that over the recent years, the plastic in many of the commercially available breathing circuits has gotten thinner. We experienced a circuit leak in the middle of a laminectomy due to compromised plastic tubing in a location that evaded the safety circuit leak check that is performed prior to surgery. This compromised ventilation and oxygenation in the middle of a surgery in which the patient is positioned prone and hence with a minimally accessible airway; it could have resulted in anoxic brain injury or death. The incident led us to reflect on the degree of thinness of the circuit's plastic.

Quality Fade in Medical Device Manufacturing: Thinness of Airway Breathing Circuit Plastic

Mechanical respirators typically use a plastic circuit apparatus to pass gases from the ventilator to the patient. Structural integrity of these circuits is crucial for maintaining oxygenation. Anesthesiologists, respiratory therapists, and other critical care professionals rely on the circuit to be free of defects. The American Society for Testing and Materials maintains standards of medical devices and had a standard (titled Standard Specification for Anesthesia Breathing Tubes) that included circuits. This standard, which was last updated in 2008, has since been withdrawn. Lack of a defined standard can invite quality fade-the phenomenon whereby manufacturers deliberately but surreptitiously reduce material quality to widen profit margins. With plastics, this is often in the form of thinner material. A minimum thickness delineated in the breathing circuit standard would help ensure product quality, maintain tolerance to mechanical insults, and avert leaks. Our impression is that over the recent years, the plastic in many of the commercially available breathing circuits has gotten thinner. We experienced a circuit leak in the middle of a laminectomy due to compromised plastic tubing in a location that evaded the safety circuit leak check that is performed prior to surgery. This compromised ventilation and oxygenation in the middle of a surgery in which the patient is positioned prone and hence with a minimally accessible airway; it could have resulted in anoxic brain injury or death. The incident led us to reflect on the degree of thinness of the circuit's plastic.

Healthful aging mediated by inhibition of oxidative stress

The progressive increase in lifespan over the past century carries with it some adversity related to the accompanying burden of debilitating diseases prevalent in the older population. This review focuses on oxidative stress as a major mechanism limiting longevity in general, and healthful aging, in particular. Accordingly, the first goal of this review is to discuss the role of oxidative stress in limiting longevity, and compare healthful aging and its mechanisms in different longevity models. Secondly, we discuss common signaling pathways involved in protection against oxidative stress in aging and in the associated diseases of aging, e.g., neurological, cardiovascular and metabolic diseases, and cancer. Much of the literature has focused on murine models of longevity, which will be discussed first, followed by a comparison with human models of longevity and their relationship to oxidative stress protection. Finally, we discuss the extent to which the different longevity models exhibit the healthful aging features through physiological protective mechanisms related to exercise tolerance and increased β-adrenergic signaling and also protection against diabetes and other metabolic diseases, obesity, cancer, neurological diseases, aging-induced cardiomyopathy, cardiac stress and osteoporosis.

Mechanisms of increased vascular stiffness down the aortic tree in aging, premenopausal female monkeys

Protection against increased vascular stiffness in young women is lost after menopause. However, little is known about vascular stiffness in older, premenopausal females, because most of the prior work has been conducted in rodents, which live for only 1-3 yr and do not go through menopause. The goal of the current investigation was to quantitate differences in stiffness down the aortic tree and the mechanisms mediating those differences in older, premenopausal (24 ± 0.7 yr) versus young adult (7 ± 0.7 yr) female nonhuman primates. Aortic stiffness (β), calculated from direct and continuous measurements of aortic diameter and pressure in chronically instrumented, conscious macaque monkeys, increased 2.5-fold in the thoracic aorta and fivefold in the abdominal aorta in old premenopausal monkeys. The aortic histological mechanisms mediating increased vascular stiffness, i.e., collagen/elastin ratio, elastin, and collagen disarray, and the number of breaks in elastin and collagen fibers were greater in the old premenopausal versus young monkeys and greater in the abdominal versus the thoracic aorta and greatest in the iliac artery. In addition, more immature and less cross-linked fibers of collagen were found in the aortas of young females. Aortic stiffness increased in old premenopausal female monkeys, more so in the abdominal aorta than in the thoracic aorta. Histological mechanisms mediating the increased aortic stiffness were augmented in the old premenopausal females, greater in the abdominal versus the thoracic aorta, and greatest in the iliac artery.NEW & NOTEWORTHY This is the first study to examine vascular stiffness down the aortic tree in aging premenopausal females (24 ± 0.7 yr old), whereas prior work studied mainly rodents, which are short-lived and do not undergo menopause. Histological mechanisms mediating vascular stiffness in older premenopausal females increased progressively down the aortic tree, with greater increases in the abdominal aorta compared with the thoracic aorta and with the greatest increases and differences observed in the iliac artery.

Rats are protected from the stress of chronic pressure overload compared with mice

The goal of this investigation was to compare the effects of chronic (4 wk) transverse aortic constriction (TAC) in Sprague-Dawley rats and C57BL/6J mice. TAC, after 1 day, induced similar left ventricular (LV) pressure gradients in both rats (n = 7) and mice (n = 7) (113 ± 5.4 vs. 103 ± 11.5 mmHg), and after 4 wk, the percent increase in LV hypertrophy, as reflected by LV/tibial length (51% vs 49%), was similar in rats (n = 12) and mice (n = 12). After 4 wk of TAC, LV systolic and diastolic function were preserved in TAC rats. In contrast, in TAC mice, LV ejection fraction decreased by 31% compared with sham, along with increases in LV end-diastolic pressure (153%) and LV systolic wall stress (86%). Angiogenesis, as reflected by Ki67 staining of capillaries, increased more in rats (n = 6) than in mice (n = 6; 10 ± 2 vs. 6 ± 1 Ki67-positive cells/field). Myocardial blood flow fell by 55% and coronary reserve by 28% in mice with TAC (n = 4), but they were preserved in rats (n = 4). Myogenesis, as reflected by c-kit-positive myocytes staining positively for troponin I, is another mechanism that can confer protection after TAC. However, the c-kit-positive cells in rats with TAC were all negative for troponin I, indicating the absence of myogenesis. Thus, rats showed relative tolerance to severe pressure overload compared with mice, with mechanisms involving angiogenesis but not myogenesis.

Abstract P113: Anti-Hypertensive Properties of Brown Adipose Tissue

The regulator of G protein signaling 14 (RGS14) knockout (KO) mice live longer than their wild type (WT) littermates and are protected against myocardial infarction, diabetes and obesity, and reduced exercise tolerance; all features of cardiovascular risk protection and healthful aging. The major mechanism mediating these features of healthful aging is their brown adipose tissue (BAT), since after BAT removal, the RGS14 KO mice lose these features of healthful aging. The goal of this investigation was to determine if the RGS14 KO and its BAT is a unique mechanism to protect against hypertension. Angiotensin II was chronically infused by osmotic pumps (1.44 mg/kg/day) for 2 wks. Mean arterial pressure (MAP) was measured by tail-cuff, stroke volume was measured by cardiac echocardiography. Cardiac output was calculated as the product of stroke volume and heart rate and total peripheral resistance (TPR) was calculated as mean MAP/cardiac output. There were no differences in baseline heart rate (434 ± 19 vs 439 ± 18 beats/min), MAP (82 ± 3.0 vs. 87 ± 1.8 mmHg), and TPR (3.8 ± 0.3 vs 3.9 ± 0.3 mmHg/mL/min) in RGS14 KO and WT prior to the angiotensin II. After 2 weeks of angiotensin II MAP and TPR rose by 70 ± 10.4 % and 43 ± 11.2%, respectively in WT. Surprisingly, in RGS14 KO 2 weeks of angiotensin II increased MAP significantly less, p<0.05, than WT, i.e., by only 11 ± 6.5%, and TPR did not increase at all. Transplantation of BAT to WT recipients also significantly diminished, p<0.05, the hypertensive effects of angiotensin II, with BAT donors exhibiting increased MAP by 70% and TPR by 78%, but in BAT recipients MAP rose by only 23% and TPR rose by only 6.5%. The second goal was to determine if BAT protects against hypertension through angiogenesis/arteriogenesis, a potential mechanism mediating protection against hypertension. Both VEGF and eNOS increased, p<0.05, in RGS14 KO BAT tissues. Thus, inhibition of RGS14 and BAT are novel mechanisms to protect against hypertension.

The Dry Eye Assessment and Management (DREAM) extension study - A randomized clinical trial of withdrawal of supplementation with omega-3 fatty acid in patients with dry eye disease

PURPOSE

To determine effects of continued or discontinued use of omega-3 (ω3) fatty acid supplements through a randomized withdrawal trial among patients assigned to ω3 supplements in the first year of the DREAM study.

METHODS

Patients who were initially assigned to ω3 (3000 mg) for 12 months in the primary trial were randomized 1:1 to ω3 active supplements or placebos (refined olive oil) for 12 more months. The primary outcome was change in the Ocular Surface Disease Index (OSDI) score. Secondary outcomes included change in conjunctival staining, corneal staining, tear break-up time, Schirmer test, and adverse events.

RESULTS

Among 22 patients assigned to ω3 and 21 to placebo supplements, the mean change in OSDI score between month 12 and 24 was similar between treatment groups (mean difference in change -0.6 points, 95% confidence interval [CI], (-10.7, 9.5), p = 0.91). There were no significant differences between groups in mean change in conjunctival staining (difference in mean change -0.5 points; 95% CI (-1.2, 0.3)), corneal staining (-0.3 points; 95% CI (-1.2, 0.3)), tear break-up time (-0.8 s; 95% CI (-2.6, 0.9)) and Schirmer test (0.6 mm, 95% CI (-2.0, 3.2)). Rates of adverse events were similar in both groups.

CONCLUSION

Among patients who received ω3 supplements for 12 months in the primary trial, those discontinuing use of ω3 for an additional 12 months did not have significantly worse outcomes compared to those who continued use of ω3. ClinicalTrials.gov number NCT02128763.

Mechanisms of sex differences in exercise capacity

Sex differences are an important component of National Institutes of Health rigor. The goal of this investigation was to test the hypothesis that female mice have greater exercise capacity than male mice, and that it is due to estrogen, nitric oxide, and myosin heavy chain expression. Female C57BL6/J wild-type mice exhibited greater (P < 0.05) maximal exercise capacity for running distance (489 ± 15 m) than age-matched male counterparts (318 ± 15 m), as well as 20% greater work to exhaustion. When matched for weight or muscle mass, females still maintained greater exercise capacity than males. Increased type I and decreased type II myosin heavy chain fibers in the soleus muscle from females are consistent with fatigue resistance and better endurance in females compared with males. After ovariectomy, female mice no longer demonstrated enhanced exercise, and treatment of male mice with estrogen resulted in exercise capacity similar to that of intact females (485 ± 37 m). Nitric oxide synthase, a downstream target of estrogen, exhibited higher activity in female mice compared with male mice, P < 0.05, whereas ovariectomized females exhibited nitric oxide synthase levels similar to males. Nitric oxide synthase activity also increased in males treated with chronic estrogen to levels of intact females. Nitric oxide synthase blockade with Nω-nitro-l-arginine methyl ester eliminated the sex differences in exercise capacity. Thus estrogen, nitric oxide, and myosin heavy chain expression are important mechanisms mediating the enhanced exercise performance in females.

Enhanced longevity and metabolism by brown adipose tissue with disruption of the regulator of G protein signaling 14

Disruption of the regulator for G protein signaling 14 (RGS14) knockout (KO) in mice extends their lifespan and has multiple beneficial effects related to healthful aging, that is, protection from obesity, as reflected by reduced white adipose tissue, protection against cold exposure, and improved metabolism. The observed beneficial effects were mediated by improved mitochondrial function. But most importantly, the main mechanism responsible for the salutary properties of the RGS14 KO involved an increase in brown adipose tissue (BAT), which was confirmed by surgical BAT removal and transplantation to wild-type (WT) mice, a surgical simulation of a molecular knockout. This technique reversed the phenotype of the RGS14 KO and WT, resulting in loss of the improved metabolism and protection against cold exposure in RGS14 KO and conferring this protection to the WT BAT recipients. Another mechanism mediating the salutary features in the RGS14 KO was increased SIRT3. This mechanism was confirmed in the RGS14 X SIRT3 double KO, which no longer demonstrated improved metabolism and protection against cold exposure. Loss of function of the Caenorhabditis elegans RGS-14 homolog confirmed the evolutionary conservation of this mechanism. Thus, disruption of RGS14 is a model of healthful aging, as it not only enhances lifespan, but also protects against obesity and cold exposure and improves metabolism with a key mechanism of increased BAT, which, when removed, eliminates the features of healthful aging.

In Vivo Efficacy of Histatin-1 in a Rabbit Animal Model

Purpose/Aim: Corneal abrasions and nonhealing corneal epithelial defects are common conditions that cause pain and sometimes are slow to heal. Histatins, a family of histidine-rich peptides, have been implicated in oral and skin epithelial wound healing, and have been shown to be effective in vitro in human corneal epithelial cells. The objective of this study was to test the efficacy of histatin-1 on corneal epithelial wound healing in rabbits.

MATERIALS & METHODS

Twenty-two (22) rabbits were separated into four treatment groups, each containing 3-7 rabbits. Treatments included three histatin-1 formulations (0.1 ug/ml. 1 ug/ml, and 10 ug/ml) and one inactive vehicle, one drop given three times per day. Eight (8) mm circular wounds were created using 0.5 ml of 20% ethyl alcohol in the right eye of each rabbit. A masked observer photographed each eye twice daily using slit-lamp biomicrophotography. Wound area was analyzed by using ImageJ. Statistical analysis was conducted using Graphpad Prism.

RESULTS

Wound recovery was faster in animals given 0.1 ug/ml, 1 ug/ml, and 10 ug/ml when compared to the vehicle solution at 6, 24, and 30 hours after wound creation (p < 0.01). No adverse events were observed in any eyes. When analyzing area under the curve, % recovered area was higher overall in the 0.1 ug/ml (p < 0.01), 1 ug/ml (p < 0.01), and 10 ug/ml (p < 0.001) groups when compared to the vehicle solution. Hourly healing rate was also observed to be faster in the 0.1 ug/ml, 1 ug/ml, and 10 ug/ml groups (p < 0.001) at 24 hours postinjury suggesting an accelerated healing process as compared to the vehicle group.

CONCLUSION

This study represents the first in vivo experiment evaluating and confirming the efficacy of topical histatin on the corneal epithelium wound healing. Further studiesare warranted to better understand the mechanism and safety of topical histatin-1 in corneal epithelial wound-healing and its potential role for human disease treatment.

Abstract 350: Brown Adipose Tissue, a Novel Mechanism to Induce both Angiogenesis and Arteriogenesis

Brown adipose tissue (BAT) is known to protect metabolism, but the extent to which it mediates angiogenesis and cardioprotection, the goal of this investigation, is not known. The Regulator of G Protein Signaling 14 (RGS14) knockout (KO) mouse is unique in that it not only extends longevity, but also enhances several aspects of healthful aging, i.e., protects against diabetes, obesity, exercise intolerance and increased brown adipose tissue by 47% compared with wild type littermates (WT). However, less is known about its role in cardioprotection. Accordingly we examined the effects of chronic myocardial ischemia after 1 and 3 weeks of permanent coronary artery occlusion (CAO) in 3-4 month old RGS14 KO and their WT. Scar size after 3 weeks CAO, determined by histology, was decreased by 33±5% in RGS14 KO, which was only possible in the face of permanent CAO if angiogenesis/arteriogenesis developed in the RGS14 KO mice hearts. Indeed, both angiogenesis assessed by Ki 67 endothelial cell staining and arteriogenesis, assessed by Ki 67 arteriole staining, more than doubled compared with WT. This was associated with a 206±25.5% increase in VEGF in the RGS14 KO hearts compared with WT. We then examined the role of BAT by using a simulated BAT KO, i.e., BAT was transplanted from the RGS14 KO to WT. In the WT with BAT transplants VEGF was increased by 90%. Infarct size, assessed as the fraction of area at risk, was lower, p<0.05, in the BAT transplants (27±2.8%), compared with infarct size in RGS14 KO donors (44±1.9%), a value similar to that observed in WT without the BAT transplant (46±1.0%). Thus, brown adipose tissue appears to be a novel mechanism to induce both angiogenesis and arteriogenesis, resulting in vascular protection from ischemia.

Disruption of adenylyl cyclase type 5 mimics exercise training

Exercise training is key to healthful longevity. Since exercise training compliance is difficult, it would be useful to have a therapeutic substitute that mimicked exercise training. We compared the effects of exercise training in wild-type (WT) littermates with adenylyl cyclase type 5 knock out (AC5 KO) mice, a model of enhanced exercise performance. Exercise performance, measured by maximal distance and work to exhaustion, was increased in exercise-trained WT to levels already attained in untrained AC5 KO. Exercise training in AC5 KO further enhanced their exercise performance. The key difference in untrained AC5 KO and exercise-trained WT was the β-adrenergic receptor signaling, which was decreased in untrained AC5 KO compared to untrained WT but was increased in WT with exercise training. Despite this key difference, untrained AC5 KO and exercise-trained WT mice shared similar gene expression, determined by deep sequencing, in their gastrocnemius muscle with 183 genes commonly up or down-regulated, mainly involving muscle contraction, metabolism and mitochondrial function. The SIRT1/PGC-1α pathway partially mediated the enhanced exercise in both AC5 KO and exercise-trained WT mice, as reflected in the reduced exercise responses after administering a SIRT1 inhibitor, but did not abolish the enhanced exercise performance in the AC5 KO compared to untrained WT. Increasing oxidative stress with paraquat attenuated exercise performance more in untrained WT than untrained AC5 KO, reflecting the augmented oxidative stress protection in AC5 KO. Blocking nitric oxide actually reduced the enhanced exercise performance in untrained AC5 KO and trained WT to levels below untrained WT, demonstrating the importance of this mechanism. These results suggest that AC5 KO mice, without exercise training, share similar mechanisms responsible for enhanced exercise capacity with chronic exercise training, most importantly increased nitric oxide, and demonstrate more reserve with the addition of exercise training. A novel feature of the enhanced exercise performance in untrained AC5 KO mice is their decreased sympathetic tone, which is also beneficial to patients with cardiovascular disease.

Abstract P427: Inhibition of the Regulator of G Protein Signaling 14, a Novel Anti-Hypertensive Mechanism

The Regulator of G Protein Signaling 14 (RGS14) knockout (KO) mouse is unique in that it not only extends longevity, but also enhances several aspects of healthful aging. The RGS14 KO mouse, compared with wild type (WT), is protected against obesity and diabetes, and has increased exercise capacity, similar to levels achieved with chronic exercise training, all potentially important anti-hypertensive mechanisms. The goal of this investigation was to test more directly that the RGS14 KO mouse is protected against hypertension. Accordingly, we chronically infused angiotensin II (1.44 mg/kg/day) by implanted osmotic pump for 14 days. Stroke volume was measured by cardiac echocardiography. Cardiac output was calculated as the product of stroke volume and heart rate. Heart rates were not different in WT and RGS14 KO prior to angiotensin II infusion or after infusion (425±11 beats/min in WT vs. 420±13 beats/min in KO). Prior to angiotensin II baseline values for mean arterial pressure were similar in WT (84±3 mmHg) and RGS14 KO (79±2 mmHg) and baseline values for systemic vascular resistance, calculated as mean arterial pressure/cardiac output, were also similar in WT (3.7±0.1 mmHg/mL/min) and RGS14 KO (2.2±0.2 mmHg/mL/min) before angiotensin II infusion. As expected, the angiotensin infusion for 14 days increased mean arterial pressure by 69±8 % and systemic vascular resistance by 43±9 % in WT. Surprisingly, angiotensin II failed to increase either mean arterial blood pressure or systemic vascular resistance significantly in RGS14 KO mice. Thus the increases in arterial pressure and vasoconstriction, pathognomonic of angiotensin II, were completely blocked in the RGS14 KO mouse, implicating this mechanism as a potential novel therapeutic modality for treating hypertension.

Retrospective report of antimicrobial susceptibility observed in bacterial pathogens isolated from ocular samples at Mount Sinai Hospital, 2010 to 2015

BACKGROUND

Antimicrobial resistance has emerged as a major threat to global public health. Thus, the surveillance of changes in antimicrobial resistance in local and global settings is a paramount necessity. While many studies have tracked antimicrobial resistance, only a small percentage surveyed ocular isolates. The purpose of this study was to report the in vitro susceptibility of bacterial pathogens isolated from ocular samples in New York, NY from 2010 to 2015.

METHODS

A retrospective review of ocular isolates was conducted. All organisms were collected by 25 separate inpatient wards and outpatient clinics, and were analyzed by the clinical microbiology laboratory at Mount Sinai Hospital. Clinical Laboratory and Standards Institute (CLSI) guidelines were followed for susceptibility testing and breakpoint interpretations.

RESULTS

A total of 549 bacterial organisms were isolated from 1664 cultures (33%) during the 6-year study period. Of these, 358 isolates (65.2%) underwent susceptibility testing. 182 (50.8%) isolates were Gram-positive. The most common Gram-positive bacterium was Staphylococcus aureus (62.1%). Methicillin-resistance decreased in S. aureus isolates (31.3% in 2010, 14.1% in 2015) but was without significant change (p = 0.25). When analyzing all S. aureus isolates recovered during the study period, there were significantly more methicillin-resistant S. aureus (MRSA) isolates resistant to fluoroquinolones (p <0.0001), erythromycin (p <0.0001), and trimethoprim/sulfamethoxazole (TMP/SMZ; p <0.05). Overall, Streptococcus pneumoniae isolates showed reduced susceptibility to erythromycin, but were otherwise susceptible to the other antimicrobials tested. Haemophilus influenzae (26.1%) and Pseudomonas aeruginosa (23.9%) were the most common Gram-negative bacteria isolated. Resistance to ampicillin and TMP/SMZ was observed in several of the H. influenzae isolates. P. aeruginosa isolates did not show high resistance overall, however, it was noted that isolates resistant to meropenem were also resistant to other antimicrobials (p < 0.01).

CONCLUSION

Overall, antimicrobial resistance was infrequent for the Gram-negative and Gram-positive bacteria analyzed. While the MRSA isolates demonstrated increased resistance to multiple antimicrobial classes, this is expected for this pathogen. Due to the continued use of broad-spectrum oral and systemic antimicrobials to treat ocular infections, findings of this study and other surveillance studies specific to ocular isolates should be used as resources in effective decision making in the treatment of ocular disease.