Stimulus type and duration affect magnitude and evolution of flicker-induced hyperemia measured by laser speckle flowgraphy at the optic disc and peripapillary vessels

Neurovascular coupling is a vital mechanism employed by the cerebrovascular system, including the eye, to regulate blood flow in periods of neuronal activation. This study aims to investigate if laser speckle flowgraphy (LSFG) can detect coupling response elicited by flickering light stimuli and how variations in stimulus type and duration can affect the magnitude and evolution of blood flow in the optic nerve head (ONH) and peripapillary vessels. Healthy adults were exposed to two types of 10-Hz flicker stimuli: a photopic negative response-like stimulus (PhNR-S) or a visual evoked potential-like stimulus (VEP-S)-each presented in separate 10- and 60-s epochs. Both PhNR-S and VEP-S significantly increased ONH blood flow (p < 0.001) immediately after flicker cessation, with a trend of 60-s stimuli (PhNR-S = 11.6%; VEP-S = 10.4%) producing a larger response than 10-s stimuli (PhNR-S = 7.5%; VEP-S = 6.2%). Moreover, exposure to 60-s stimuli elicited a significantly prolonged ONH hyperemic response, especially with PhNR-S. Lastly, stimulation with either 60-s stimuli elicited a robust increase in blood flow within the peripapillary arterioles (p < 0.01) and venules (p < 0.01) as well. Flicker stimulation with common visual electrophysiology stimuli (PhNR-S and VEP-S) induced a demonstrable increase in ONH and peripapillary vessel blood flow, which varied with flicker duration. Our results validate that LSFG is a robust method to quantify flicker-induced hyperemic responses and to study neurovascular coupling in humans.

SGLT2 inhibitors and diabetic retinopathy progression

PURPOSE

To evaluate whether sodium-glucose co-transporter 2 (SGLT2) inhibitors affect progression of non-proliferative diabetic retinopathy (NPDR) compared to standard of care.

METHODS

A retrospective cohort study compared subjects enrolled in a commercial and Medicare Advantage medical claims database who filled a prescription for a SGLT2 inhibitor between 2013 and 2020 to unexposed controls, matched up to a 1:3 ratio. Patients were excluded if they were enrolled for less than 2 years in the plan, had no prior ophthalmologic exam, had no diagnosis of NPDR, had a diagnosis of diabetic macular edema (DME) or proliferative diabetic retinopathy (PDR), had received treatment for vision-threatening diabetic retinopathy (VTDR), or were younger than 18 years. To balance covariates of interest between the cohorts, an inverse probability treatment weighting (IPTW) propensity score for SGLT2 inhibitor exposure was used. Multivariate Cox proportional hazard regression modeling was employed to assess the hazard ratio (HR) for VTDR, PDR, or DME relative to SGLT2 exposure.

RESULTS

A total of 6065 patients who initiated an SGLT2 inhibitor were matched to 12,890 controls. There were 734 (12%), 657 (10.8%), and 72 (1.18%) cases of VTDR, DME, and PDR, respectively, in the SGLT2 inhibitor cohort. Conversely, there were 1479 (11.4%), 1331 (10.3%), and 128 (0.99%) cases of VTDR, DME, and PDR, respectively, among controls. After IPTW, Cox regression analysis showed no difference in hazard for VTDR, PDR, or DME in the SGLT2 inhibitor-exposed cohort relative to the unexposed group [HR = 1.04, 95% CI 0.94 to 1.15 for VTDR; HR = 1.03, 95% CI 0.93 to 1.14 for DME; HR = 1.22, 95% CI 0.89 to 1.67 for PDR].

CONCLUSION

Exposure to SGLT2 inhibitor therapy was not associated with progression of NPDR compared to patients receiving other diabetic therapies.

Risk Factors for Chalazion Diagnosis and Subsequent Surgical Excision

PURPOSE

To identify factors associated with chalazion diagnosis and surgical excision.

METHODS

Patients with an incident chalazion diagnosis from 2002 to 2019 were compared 1:5 with matched controls. Multivariable logistic regression was performed to identify variables associated with diagnosis and surgical excision.

RESULTS

Chalazion patients (n = 134,959) and controls (678,160) were analyzed. Risk factors for diagnosis included female sex, non-white race, northeast location, conditions affecting periocular skin and tear film (blepharitis, meibomian gland dysfunction, rosacea, pterygium), non-ocular inflammatory conditions (gastritis, inflammatory bowel disease, sarcoidosis, seborrheic dermatitis, Graves' disease), and smoking (p < .001 for all comparisons). Thirteen percent of patients with chalazion underwent subsequent surgical excision. Diabetes and systemic sclerosis diagnoses decreased odds of diagnosis (p < .001). Male sex, rosacea diagnosis, Black and Hispanic race, antibiotic use, and doxycycline use increased odds of surgery (p < .001).

CONCLUSION

Female sex, non-white race, conditions affecting periocular skin and the tear film, several non-ocular inflammatory conditions, and smoking were risk factors for chalazion diagnosis. Male sex, rosacea diagnosis, Black and Hispanic race, antibiotic use, and doxycycline use were risk factors for surgical intervention for chalazion. Our results prompt further study of these variables and their relationship to chalazion diagnosis to understand physiology and improve clinical outcomes. Furthermore, the results of this study suggest early recognition and treatment of concomitant rosacea may serve an important role in the management of chalazion and in the prevention of surgical intervention.

Biphasic change in retinal nerve fibre layer thickness from 30 to 60 weeks postmenstrual age in preterm infants

BACKGROUND/AIMS

The optic nerve development during the critical postnatal weeks of preterm infants is unclear. We aimed to investigate the change of retinal nerve fibre layer (RNFL) in preterm infants.

METHODS

We used an investigational handheld optical coherence tomography (OCT) system to serially image awake preterm infants between 30 and 60 weeks postmenstrual age (PMA) at the bedside. We assessed RNFL thickness in the papillomacular bundle and nasal macular ganglion cell layer+inner plexiform layer (GCL+IPL) thickness. We applied a segmented mixed model to analyse the change in the thickness of RNFL and GCL+IPL as a function of PMA.

RESULTS

From 631 OCT imaging sessions of 101 infants (201 eyes), RNFL thickness followed a biphasic model between 30 and 60 weeks, with an estimated transition at 37.8 weeks PMA (95% CI: 37.0 to 38.6). RNFL thickness increased at 1.8 μm/week (95% CI: 1.6 to 2.1) before 37.8 weeks and decreased at -0.3 μm/week (95% CI: -0.5 to -0.2) afterwards. GCL+IPL thickness followed a similar biphasic model, in which the thickness increased at 2.9 μm/week (95% CI: 2.5 to 3.2) before 39.5 weeks PMA (95% CI: 38.8 to 40.1) and then decreased at -0.8 μm/week (95% CI: -0.9 to -0.6).

CONCLUSION

We demonstrate the feasibility of monitoring RNFL and GCL+IPL thickness from OCT during the postnatal weeks of preterm infants. Thicknesses follow a biphasic model with a transition age at 37.8 and 39.5 weeks PMA, respectively. These findings may shed light on optic nerve development in preterm infants and assist future study designs.

Long-Term Burden of Pain and Reduced Visual Acuity after Gunshot Wounds to the Orbit

PURPOSE

To characterize the clinical presentation, surgical management, long-term complications and outcomes of Gunshot Wounds(GSW) to the orbit.

METHODS

An extended case series with retrospective chart-review was conducted on all cases (1985-2020) of traumatic ocular injuries secondary to GSWs at an academic institution with a level 1 trauma center. Predictors included demographic information, clinical and radiologic examination findings, and surgical intervention at time of presentation. Outcomes included long-term lid malposition, visual acuity, pain, and secondary surgery. Descriptive statistics and tests of association were performed, including Fishers exact tests for categorical data, Kruskal-Wallis rank sum tests, analysis of variance, and, in the case of repeated measures, generalized estimating equations.

RESULTS

88 patients with GSW involving the orbit were included with average age of 32.6 years (sd = 15.7). Patients were 85.2% male, 75% African-American, 25.0% Caucasian, and 5.7% Hispanic. Median follow up was 43.3 months (4.6, 136.4). The injuries at presentation were 53.4% intracranial, 21.6% open globe, 80.7% orbital fracture, 89.8% lid laceration. Visual acuity did not significantly improve over time. Long-term complications included abnormal lid or globe position in 26.1% of patients, reduced visual acuity in 55.2%, and persistent pain in 50.6%.

CONCLUSION

To our knowledge, this represents the first and largest clinical epidemiologic study with insight into the clinical presentation, surgical intervention, and long-term outcomes of GSW to the orbit. The results demonstrate a long-term burden of persistent pain and reduced visual acuity in patients who suffer from GSW to the globe and orbit. This study may guide patient management and communications.

Systemic disease associations with angioid streaks in a large healthcare claims database

BACKGROUND/OBJECTIVES

To assess systemic associations of angioid streaks (AS) using a large US healthcare database.

SUBJECTS/METHODS

A retrospective cross-sectional study was conducted of patients diagnosed with AS in a large, national US insurer from 2000-2019. Cases were matched 1:5 to controls. The prevalence rates of established associated disease states and other systemic diseases were calculated and compared using logistic regression. Additionally, the rate of anti-VEGF treatment was assessed as a proxy for the incidence of choroidal neovascularization (CNV).

RESULTS

One thousand eight hundred fifty-two cases of AS and 9028 matched controls were included. The rates of association between AS and the well-characterized conditions included: Pseudoxanthoma elasticum (PXE)-228 patients (12.3%), Ehlers-Danlos syndrome-18 patients (1.0%), Paget's disease-6 patients (0.3%), hemoglobinopathies-30 patients (1.6%), and idiopathic-1573 patients (84.9%). There was a statistically higher prevalence of the following less classically associated diseases among patients with AS compared to controls: hereditary spherocytosis (1.7% vs. 0.6%, p < 0.001), connective tissue disease (1.0% vs 0.3%, p < 0.001) and non-exudative age-related macular degeneration (33.9% vs 10.6%, p < 0.001). Among 1442 eligible cases analyzed, 427 (29.6%) received at least 1 anti-VEGF injection with 338 (23.4%) patients having the injection after their AS diagnosis.

CONCLUSIONS

In the largest collection of AS patients to date, the classical teaching of systemic disease associations occur at rates far, far lower than previously reported. The association of AS with other less reported diseases highlights new potential associations and may contribute to the understanding of AS formation.

Associations between systemic health and retinal nerve fibre layer thickness in preterm infants at 36 weeks postmenstrual age

BACKGROUND/AIMS

Neonatal insults from systemic diseases have been implicated in the pathway of impaired neurodevelopment in preterm infants. We aimed to investigate the associations between systemic health factors and retinal nerve fibre layer (RNFL) thickness in preterm infants.

METHODS

We prospectively enrolled infants and imaged both eyes at 36±1 weeks postmenstrual age (PMA) using a hand-held optical coherence tomography system at the bedside in the Duke intensive care nurseries. We evaluated associations between RNFL thickness and 29 systemic health factors using univariable and multivariable regression models.

RESULTS

83 infants with RNFL thickness measures were included in this study. Based on the multivariable model, RNFL thickness was positively associated with infant weight at imaging and was negatively associated with sepsis/necrotising enterocolitis (NEC). RNFL thickness was 10.4 µm (95% CI -15.9 to -4.9) lower in infants with than without sepsis/NEC in the univariable analysis (p<0.001). This difference remained statistically significant after adjustment for confounding variables in various combinations (birth weight, birthweight percentile, gestational age, infant weight at imaging and growth velocity). A 250 g increase in infant weight at imaging was associated with a 3.1 µm (95% CI 2.1 to 4.2) increase in RNFL thickness in the univariable analysis (p<0.001).

CONCLUSIONS

Low infant weight and sepsis/NEC were independently associated with thinner RNFL in preterm infants at 36 weeks PMA. To our knowledge, this study is the first to suggest that sepsis/NEC may affect retinal neurodevelopment. Future longitudinal studies are needed to investigate this relationship further.

Mohs Micrographic Surgery for Facial Merkel Cell Carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is a rare malignant cutaneous tumor with frequent metastases. They often appear in the face where cosmetic and functional outcome is critical. Mohs micrographic surgery (MMS) is a controlled intervention that optimizes negative margins without sacrificing tissue.

OBJECTIVE

A comprehensive assessment of outcomes of MMS-treated facial MCC will help guide clinicians in surgical and medical management.

METHODS & MATERIALS

Retrospective review identified facial MCC cases treated with MMS at a single institution from January 2005 to August 2020. Tumor characteristics and outcomes were recorded and descriptive and predictive analyses were performed.

RESULTS

34 cases were reviewed with a mean followup of 34.4 months. The most common sites were the forehead, cheek-jaw region, and nasal ala. 2 (5.9%) patients had local recurrence by a mean of 4.3 months. No documented variables were significantly associated with local recurrence. 8 (23.5%) patients had progression to metastasis by a mean of 9.4 months. Younger age at biopsy and surgery, male sex, and intraoperative detection of in-transit disease were significantly associated with progression to metastasis.

CONCLUSIONS

In summary, the tissue-sparing approach of MMS may be beneficial for MCC in cosmetically and functionally sensitive facial locations as it preserves tissue without compromising outcomes.

Recent Practice Patterns in Acute Retinal Artery Occlusions in the United States

PURPOSE

To determine how to practice patterns for work-up of incident retinal artery occlusion (RAO) compare to the American Academy of Ophthalmology (AAO) guidelines.

METHODS

In this cohort study, patients receiving a new diagnosis of RAO, either central (CRAO) or branch (BRAO), were identified between 2002 and 2020 from a large US medical claims database. Claims were reviewed for diagnostic tests specified by the AAO as essential components of an RAO work-up including carotid ultrasound, echocardiogram, magnetic resonance imaging (MRI) and emergency department (ED) referral. Outcomes included rates of and time to completion of work-up.

RESULTS

18697 new outpatient diagnoses of RAO (11348 BRAO, 7349 CRAO) were analyzed. 15.9% and 30.4% of patients received carotid ultrasounds within 7 and 30 days, respectively. 9.4% and 21.1% of patients received echocardiograms within 7 and 30 days, respectively. 4.9% and 8.1% of patients received a brain MRIs within 7 and 30 days, respectively. Only 4.1% of patients were referred to the ED within a day of diagnosis. Ophthalmologists diagnosed the majority (78.7%) of RAOs compared to neurologists (0.6%). Patients diagnosed by ophthalmologists were significantly more likely to have carotid ultrasound within 7 days, but those diagnosed by neurologists were more likely to have echocardiogram, MRI, and ED referral (p < .01 for all comparisons). The rates of adherence to the AAO care guidelines increased significantly between 2002 and 2020 (p < .01).

CONCLUSIONS

The referral and work-up practices demonstrated in this new RAO diagnosis patient cohort have improved with time but are still far below the standard recommended by the AAO.

Prevalence and Factors Associated with Optic Disc Tilt in the Primary Open-Angle African American Glaucoma Genetics Study

PURPOSE

To investigate the prevalence and factors associated with optic disc tilt in the eyes of Black Americans with glaucoma.

DESIGN

Cross-sectional.

PARTICIPANTS

Subjects with glaucoma participating in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study.

METHODS

Stereo pairs of optic disc images were assessed independently by POAAGG-certified nonphysician graders for quantitative features including maximum and minimum linear disc diameters, and qualitative features including gradeability of images, shape of the cup, rim plane position, β-peripapillary atrophy, sloping region adjacent to the outer disc margin, and rim pallor. Discrepancies were adjudicated by an ophthalmologist. Descriptive statistics and P values were generated for associations of tilt with demographic and ocular characteristics. Stepwise multivariable analysis was performed with logistic regression using Generalized Estimating Equations (GEEs) to account for inter-eye correlation within subjects.

MAIN OUTCOME MEASURES

Tilt Ovality Index (TOI) of >1.30 and Stereoscopically Identified optic disc Tilt (SIT).

RESULTS

Among 1251 subjects with data on both eyes, 104 (8.3%) had TOI. Subjects with TOI were less likely to be male (adjusted odds ratio [aOR], 0.46, 95% confidence interval [CI], 0.29-0.74, P < 0.001). Eyes with TOI were less likely to have large cup disc ratios (aOR, 0.18, 95% CI, 0.06-0.53, P < 0.001) and less likely to have cylinder-shaped cups compared with conical-shaped cups (aOR, 0.31, 95% CI, 0.19-0.49, P < 0.001). Among 1007 subjects with data on both eyes, 254 (25.2%) had SIT. Subjects with SIT were younger (aOR, 0.95, 95% CI, 0.93-0.96, P < 0.001), and eyes with SIT were more likely to have oval-shaped discs compared with round discs (aOR, 1.82, 95% CI, 1.32-2.52, P < 0.001), more likely to have a sloping region adjacent to the outer disc margin instead of being flat (aOR, 3.26, 95% CI, 2.32-4.59, P < 0.001), and less likely to have cylinder-shaped cups compared with conical-shaped cups (aOR, 0.59, 95% CI, 0.41-0.85, P < 0.001). Both TOI and SIT were not associated with myopia.

CONCLUSIONS

There are substantial numbers of tilted optic discs in glaucoma patients with African ancestry. They occur more frequently in female subjects and younger subjects and are associated with several ocular features but not with myopia.

Changes in Intraocular Pressure with Use of Periocular Triamcinolone Cream

Purpose

To evaluate the effect of periocular topical triamcinolone cream on intraocular pressure.

Methods

A retrospective chart review identified 57 patients, 114 eyes using triamcinolone cream (0.1%, 0.025%) with subsequent intraocular pressure (IOP) checks at three follow-up visits. Descriptive, univariate, and multivariate analyses were performed to assess effects of age, therapy duration, consecutive weeks on steroid, prescription strength, time of day, and method of measurement on IOP levels. Generalized Estimating Equations were used in regression models to account for correlation of eyes within subjects and across visits.

Results

We identified 57 patients using triamcinolone cream for allergic or eczematous dermatitis of the eyelid. Prescription strengths were 0.025% or 0.1% and patients were followed for a median of 4.9 months. Measurements of IOP at baseline did not change as compared to all IOP measurements at follow-ups and did not change with steroid strength. The mean change in IOP at all follow-up visits was 0.07 mm Hg (95% confidence interval [CI]: –0.36, 0.50). After adjustment for the method of tonometer and the patient's age, the mean change was 0.03 mm Hg (95% CI: –0.68, 0.73, P = 0.93). Prescription strength and consecutive weeks of therapy were not associated with IOP. Two patients experienced a significant elevation in IOP of >10 mm Hg, one through the concomitant consequences of systemic corticosteroids usage and the other through prolonged topical application.

Conclusion

In patients taking periocular triamcinolone cream, there was no clinically meaningful change in mean IOP between baseline and follow-up visits, and IOP measurements were not related to variances in prescription strength or duration of therapy.

Association Between Retinal Microanatomy in Preterm Infants and 9-Month Visual Acuity

Importance

Preterm infants are at risk for poor visual acuity (VA) outcomes, even without retinal problems on ophthalmoscopy. Infant retinal microanatomy may provide insight as to potential causes.

Objective

To evaluate the association between preterm infant retinal microanatomy and VA at 9 months' corrected age.

Design, Setting, and Participants

This prospective observational study took place from November 2016 and December 2019 at a single academic medical center and included preterm infants enrolled in Study of Eye Imaging in Preterm Infants (BabySTEPS). Infants were eligible for enrollment in BabySTEPS if they met criteria for retinopathy of prematurity (ROP) screening, were 35 weeks' postmenstrual age or older at the time of first OCT imaging, and a parent or guardian provided written informed consent. Of 118 infants enrolled in BabySTEPS, 61 were included in this analysis. Data were analyzed from March to April 2021.

Exposures

Bedside optical coherence tomography (OCT) imaging at a mean (SD) 39.85 (0.79) weeks' postmenstrual age and monocular grating VA measurement at 9 months' corrected age.

Main Outcomes and Measures

Presence and severity of macular edema and presence of ellipsoid zone at the fovea measured by extracting semiautomated thicknesses of inner nuclear layer, inner retina, and total retina at the foveal center; choroid across foveal 1 mm; and retinal nerve fiber layer (RNFL) across the papillomacular bundle (PMB). Pearson correlation coefficients were calculated and 95% CIs were bootstrapped for the association between retinal layer thicknesses and continuous logMAR VA. Associations were analyzed between retinal microanatomy and normal (3.70 cycles/degree or greater) vs subnormal grating VA at 9 months' corrected age using logistic regression and with logMAR VA using linear regression, adjusting for birth weight, gestational age, and ROP severity at the time of OCT imaging and accounting for intereye correlation using generalized estimating equations.

Results

The mean (SD; range) gestational age of included infants was 27.6 (2.8; 23.0-34.6) weeks, and mean (SD; range) birth weight was 958.2 (293.7; 480-1580) g. In 122 eyes of 61 infants, the correlations between retinal layer thicknesses and logMAR VA were as follows: r, 0.01 (95% CI, -0.07 to -0.27) for inner nuclear layer; r, 0.19 (95% CI, 0.01 to 0.35) for inner retina; r, 0.15 (95% CI, -0.02 to 0.31) for total retina; r, -0.22 (95% CI, -0.38 to -0.03) for choroid; and r, -0.27 (95% CI, -0.45 to 0.10) for RNFL across the PMB. In multivariable analysis, thinner RNFL across the PMB (regression coefficient, -0.05 per 10-μm increase in RNFL thickness; 95% CI, -0.10 to -0.01; P = .046) and prior ROP treatment (regression coefficient, 0.33 for ROP treatment; 95% CI, 0.11 to 0.56; P = .003) were independently associated with poorer 9-month logMAR VA.

Conclusions and Relevance

In preterm infants, RNFL thinning across the PMB was associated with poorer 9-month VA, independent of birth weight, gestational age, need for ROP treatment, and macular microanatomy. Evaluation of RNFL thickness using OCT may help identify preterm infants at risk for poor vision outcomes.

The association of stroke with central and branch retinal arterial occlusion

OBJECTIVES

To determine the near-term risk of stroke following a retinal artery occlusion (RAO).

METHODS

The risk of stroke was assessed in two manners; with a self-controlled case series (SCCS) and a propensity score (PS) matched cohort study using a US medical claims database. The date of RAO diagnosis was assigned as the index date. In the SCCS, incidence of stroke was compared in 30- and 7-day periods pre- and post-index date. In PS analysis, matched cohorts were created from patients with RAO or hip fracture. Cox proportional hazard regression assessed the hazard for stroke. Patients were censored at 1 year, upon leaving the insurance plan or if they had a qualifying event for the comparison group.

RESULTS

The SCCS included 16,193 patients with RAO. The incidence rate ratio (IRR) of new stroke in the month after RAO was increased compared to all periods >2 months before and all months after the index date (IRRs: 1.68-6.40, p < 0.012). Risk was increased in the week immediately following the index date compared to most weeks starting 2 weeks prior to and all weeks immediately after the index date (IRRs: 1.93-29.00, p < 0.026). The PS study analysed 18,213 propensity-matched patients with RAO vs. hip fracture. The HR for having a stroke after RAO compared to a hip fracture was elevated in all analyses (All RAO HR: 2.97, 95% CI: 2.71-3.26, p < 0.001; CRAO HR: 3.24, 95% CI: 2.83-3.70, p < 0.001; BRAO HR: 2.76, 95% CI: 2.43-3.13, p < 0.001).

CONCLUSIONS

The highest risk for stroke occurs in the days following a CRAO or BRAO, supporting guidelines suggesting immediate referral to a stroke centre upon diagnosis.

Comparison of Visual Acuity Results Between ATS-HOTV and E-ETDRS Testing Methods in Children With Optic Pathway Gliomas

Purpose

To determine if visual acuity (VA) outcomes are comparable using the amblyopia treatment study HOTV protocol (ATS-HOTV) and electronic Early Treatment of Diabetic Retinopathy Study (E-ETDRS) protocol in children with optic pathway gliomas (OPGs).

Methods

Children enrolled in a prospective study of OPGs were eligible if they completed both the ATS-HOTV and E-ETDRS during the same visit. The contribution of age, testing order, having neurofibromatosis type 1, visual field loss, and circumpapillary retinal nerve fiber layer thickness to VA difference were assessed using generalized estimating equations to account for the intereye correlation.

Results

Forty-eight children (median age, 10.3 years; range, 5.2-17.1 years; 49% female) met inclusion criteria and contributed 93 study eyes at their initial visit. Eleven patients (22 eyes) had more than one study visit, permitting longitudinal evaluation. ATS-HOTV measures of VA were higher than E-ETDRS at the initial (0.13 ± 0.36 vs. 0.23 ± 0.39 logarithm of the minimum angle of resolution [logMAR], P < 0.001) and all visits (0.13 ± 0.34 vs. 0.21 ± 0.36 logMAR, P < 0.001). VA remained significantly higher with ATS-HOTV regardless of test order, but the mean difference between tests was most profound when tested with ATS-HOTV first compared to E-ETDRS first (P < 0.001).

Conclusions

VA results differ significantly between the ATS-HOTV and E-ETDRS testing methods in children with OPGs. Given the wide range of ages and testing ability of children, one VA testing method should be used throughout longitudinal OPG clinical trials.

Translational Relevance

It is imperative that age-appropriate VA testing methods are standardized across all pediatric OPG clinical trials.

Statin Use and the Risk of Progression to Vision Threatening Diabetic Retinopathy

PURPOSE

This study aims to assess the effect of statins on progression from nonproliferative diabetic retinopathy (NPDR) to vision-threatening diabetic retinopathy (VTDR), proliferative diabetic retinopathy (PDR) or diabetic macular edema (DME).

METHODS

Two cohort studies using a U.S. medical claims database from 2002 to 2019 including NPDR patients 18 years or older. A risk factor analysis performed a time-updating cox regression model assessing statin usage. A second new-user active comparator design analysis replicating a previously published study. Main outcomes included a new diagnosis of VTDR (composite of either PDR or DME) or DME and PDR individually for the risk factor study and included additional outcomes of new DR, NPDR, vitreous hemorrhage (VH) and tractional retinal detachment (TRD) for the new user study.

RESULTS

Risk factor analysis included 66 617 statin users with NPDR at baseline and 83 365 nonstatin users. Of these, 27 325 (18.2%) progressed to VTDR, 4086 (2.71%) progressed to PDR, and 22 750 (15.1%) progressed to DME. After multivariable analysis, no protective effect of statin use was found for progression to VTDR, PDR, or DME (HR = 1.01-3, p >0.33 for all comparisons). Replicated new user design analysis also showed no protective effect for statins on risk of development of DR (HR = 1.03, 95% CI: 0.99-1.07, p = 0.13), PDR (HR = 0.89, 95% CI: 0.79-1.02, p = 0.09), DME (HR = 0.94, 95% CI: 0.86-1.03, p = 0.21), VH (HR = 1.00, 95% CI: 0.86-1.16, p = 0.99), and TRD (HR = 1.11, 95% CI: 0.89-1.38, p = 0.36).

CONCLUSION

Statin use was found not to be protective for progression of DR regardless of study methodology. These results suggest that the specifics of the population studied rather than differing study methodology are important in assessing the effect of statins on DR progression.

Clinicopathologic Characteristics and Prognostic Factors Impacting Survival in Melanoma of the Eyelid

PURPOSE

To examine prognostic factors for survival in patients with melanoma of the eyelid.

DESIGN

Retrospective cohort study.

METHODS

This population-based study reviewed patients with primary melanoma of the eyelid diagnosed in the Surveillance, Epidemiology and End Results database between 1975 and 2016. The primary outcomes included survival rates estimated by Kaplan-Meier analysis and mortality hazard ratios (HRs) for overall survival and disease-specific survival (DSS).

RESULTS

The cohort consisted of 2257 patients with cutaneous melanoma of the eyelid, representing 1380 cases of melanoma in situ and 877 cases of invasive melanoma. For melanoma in situ and invasive melanoma respectively, at 5 years, the overall survival rates were 88.6% and 77.1%, while DSS rates were 99.4% and 91.0%. Cox regression analysis for eyelid melanoma indicated that for invasive melanoma, age at diagnosis ≥75 years (HR 2.17 [95% confidence interval {CI} 1.02-4.60]; P = .04), T4 staging (HR 8.45 [95% CI 2.96-25.31]; P < .001), lymph node involvement (HR 3.61 [95% CI 1.12-11.60]; P = .03), and nodular melanoma (HR 3.31 [95% CI 1.50-7.32]; P = .003) histologic subtype were associated with decreased rates of survival. Sex and tumor ulceration did not impact survival.

CONCLUSIONS

This study is the largest analysis to date that focuses on DSS for cutaneous melanoma of the eyelid. The most significant predictors for invasive melanoma survival are age ≥75 years at diagnosis, T4 staging, lymph node involvement, and the nodular melanoma histologic subtype. Patients with these attributes are at higher risk and should be counseled regarding prognosis.

Risk of non-infectious uveitis or myasthenia gravis in patients on checkpoint inhibitors in a large healthcare claims database

AIM

To determine if checkpoint inhibitors (CPIs) confer an increased risk of non-infectious uveitis or myasthenia gravis (MG) compared to patients on non-checkpoint inhibitor (N-CPI) chemotherapy.

METHODS

A retrospective cohort study was performed comparing patients in a large commercial and Medicare advantage database exposed to CPI compared to N-CPI. All patients who initiated a CPI (ipilimumab, pembrolizumab, nivolumab, atezolizumab, avelumab, cemiplimab and durvalumab) were eligible. Date of earliest CPI in the exposure group and N-CPI chemotherapy in the comparator group was considered the index date. Exclusion occurred in both cohorts for any history of uveitis or MG diagnosis and having <1 year in the insurance plan prior to the index date, and <6 months in plan following the index date. Every exposed patient was matched up to 1:10 based on demographics and index year to patients on N-CPI chemotherapy. Multivariate Cox proportional hazards regression modelling was performed.

RESULTS

For evaluation of incidence of non-infectious uveitis, 26 (0.3%) of 8678 patients on CPI and 123 (0.2%) of 76 153 N-CPI comparators were found to have non-infectious uveitis. After multivariate analysis, CPIs showed an increased hazard for uveitis compared to N-CPI (HR=2.09; 95% CI 1.36 to 3.22, p=0.001). For the MG analysis, 11 (0.1%) of 9210 patients developed MG in the CPI group and 36 (0.04%) of 80 620 comparators. The CPI cohort had a higher hazard of developing MG (HR=2.60; 95% CI 1.34 to 5.07, p=0.005) compared to controls in multivariate analysis.

CONCLUSIONS

Exposure to CPI confers a higher risk for non-infectious uveitis and MG compared to N-CPI chemotherapy.

Effect of teprotumumab on intraocular pressure in thyroid-associated ophthalmopathy

PURPOSE:

MATERIALS AND METHODS:

RESULTS:

CONCLUSION:

Hypercoagulability Testing and Hypercoagulable Disorders in Young Central Retinal Vein Occlusion Patients

PURPOSE

To determine frequency of hypercoagulability testing and hypercoagulable states in patients with central retinal vein occlusion (CRVO) younger than 50 years.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Deidentified patients younger than 50 years with newly diagnosed CRVO from a national insurance claims database.

METHODS

The de-identified Clinformatics Data Mart Database (Optum) containing medical claims from a commercial and Medicare Advantage insurance database was used. All outpatient medical claims (office visits, associated diagnoses, and laboratory testing) and demographic data for each beneficiary during their enrollment were accessible.

MAIN OUTCOME MEASURES

Prevalence of (1) laboratory hypercoagulable workup within 90 days of CRVO diagnosis, (2) new diagnosis of a hypercoagulable state within 1 year of CRVO diagnosis, and (3) diagnosis of hypertension, diabetes mellitus (DM), and hyperlipidemia.

RESULTS

One thousand one hundred eighty-one patients met inclusion criteria. Six hundred seventy-one patients (56.8%) were men, 450 patients (38.1%) had undergone hypercoagulable testing within 90 days, and 136 patients (11.5%) were diagnosed with a hypercoagulable state within 1 year after CRVO diagnosis. This proportion was similar between those patients with DM, hypertension, or hyperlipidemia (10.5% [65/620]) and those without (12.7% [71/561]; P = 0.28). Of the 136 patients diagnosed with a hypercoagulability state, 68.4% (93/136) had undergone testing within 90 days of CRVO diagnosis and 31.6% (43/136) did not. Of those who had not undergone hypercoagulability testing, 5.9% (43/731) were diagnosed with a hypercoagulable state within 1 year compared with 20.7% (93/450) in those who were tested (P < 0.001).

CONCLUSIONS

The prevalence of a hypercoagulable state within 1 year of CRVO diagnosis in patients younger than 50 years was 11.5%, and the prevalence was similar between patients with atherosclerotic risk factors and those without. Rate of testing was only 38.1%. Future research should examine the usefulness of uniform hypercoagulable testing in young CRVO patients.

Primary orbital melanoma: A report of a case and comprehensive review of the literature

Purpose: To review the clinical features and treatment-associated outcomes of primary orbital melanoma among cases reported in the literature and to present a case treated with orbital exenteration and post-operative radiotherapy.Methods: Case reports and case series on primary orbital melanoma published in the literature between 1980 and 2020 were reviewed. Data collected included patient demographics, presenting ocular symptoms, diagnostic imaging, histology, management, and outcomes.Results: Eighty-eight cases of primary orbital melanoma were reviewed. The average age at presentation was 45 years and 58% of patients were male. The most common presenting symptoms and signs were proptosis (73%), decreased visual acuity (32%), pain (14%), diplopia (15%), and palpable mass (9%). Imaging frequently showed a well-circumscribed enhancing lesion. Diagnosis was made by histology in all cases, and orbital blue nevus was identified in 42%. In the majority of cases, treatment consisted of orbital exenteration (54%) or excision (38%). Adjuvant radiotherapy was given in 47% of cases. For the 72 patients with reported outcomes, 36% had metastases, 15% had local recurrence, and 32% died of metastatic disease. Patients who received surgery and radiotherapy had improved survival compared to those who received surgery alone (p = .01). There was no difference in survival between those who underwent orbital exenteration or excision (p = .16).Conclusions: Primary orbital melanoma is a rare malignancy and should be considered in patients with a history of unilateral proptosis and a well-defined orbital mass on imaging. Surgery remains the mainstay of treatment. Adjuvant radiotherapy may improve patient survival.

LMX1B Locus Associated with Low-Risk Baseline Glaucomatous Features in the POAAGG Study

Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide and has been associated with multiple genetic risk factors. The LMX1B gene is a genetic susceptibility factor for POAG, and several single-nucleotide polymorphisms (SNPs) were shown to be associated with POAG in our own prior Primary Open-Angle African American Glaucoma Genetics (POAAGG) study genome-wide association study (GWAS). This study evaluated the association of the LMX1B locus with baseline optic disc and clinical phenotypic characteristics of glaucoma patients from our African American cohort. Compared to the GG genotype in SNP rs187699205, the GC genotype in this SNP was found to be significantly associated with a smaller cup-to-disc ratio (CDR) and increased (better) visual field mean deviation (MD) in glaucoma cases. None of the glaucoma cases with the GC genotype had disc hemorrhages, disc notching, or beanpot disc appearance. In conclusion, glaucoma phenotypes differed significantly by LMX1B variant in African American patients with POAG, and a SNP variant was associated with certain disease features considered lower risk.

Preterm Infant Stress During Handheld Optical Coherence Tomography vs Binocular Indirect Ophthalmoscopy Examination for Retinopathy of Prematurity

Importance

Binocular indirect ophthalmoscopy (BIO) examination for retinopathy of prematurity (ROP) is a well-known cause of repeated preterm infant stress.

Objective

To compare stress during investigational optical coherence tomography (OCT) imaging to that during BIO for ROP.

Design, Setting, and Participants

This cross-sectional study examined infants at the bedside in the intensive care nursery. Consecutive preterm infants enrolled in Study of Eye Imaging in Preterm Infants (BabySTEPS) who had any research OCT imaging as part of the study. Patients were recruited from June to November 2019, and analysis began April 2020.

Main Outcomes and Measures

Infant stress was measured using modified components of a neonatal pain assessment tool before (baseline) and during OCT imaging and BIO examination of each eye.

Results

For 71 eye examinations of 16 infants (mean [SD] gestational age, 27 [3] weeks; birth weight, 869 [277] g), change from baseline to each eye examination was lower during OCT imaging than during BIO and the difference between OCT imaging and BIO at each eye examination was significant for the following: infant cry score (first eye examination: mean [SD], 0.03 [0.3] vs 1.68 [1.2]; -1.65 [95% CI, -1.91 to -1.39]; second eye examination: mean [SD], 0.1 [0.3] vs 1.97 [1.2]; -1.87 [95% CI, -2.19 to -1.54]), facial expression (first eye: 3 [4%] vs 59 [83%]; -79% [95% CI, -87% to -72%]; second eye: 4 [6%] vs 61 [88%]; -83% [95% CI, -89% to -76%]), and heart rate (first eye: mean [SD], -7 [16] vs 13 [18]; -20 [95% CI, -26 to -14]); second eye: mean [SD], -3 [18] vs 20 [20] beats per minute; -23 [95% CI, -29 to -18]) (P < .001 for all). Change in respiratory rate and oxygen saturation did not differ between OCT imaging and BIO.

Conclusions and Relevance

While the role of OCT alone or in combination with BIO is currently unknown for ROP, these findings suggest that investigational OCT imaging of ROP is less stressful than BIO examination by a trained ophthalmologist.

Association of metformin and development of dry age-related macular degeneration in a U.S. insurance claims database

PURPOSE

To assess whether metformin is associated with dry age-related macular degeneration (dAMD) development.

METHODS

In this retrospective cohort study, patients enrolled in a nationwide U.S. medical insurance claims database from 2002 to 2016 were included if they had diabetes mellitus, were ⩾55 years old, and were enrolled for ⩾2 years without a prior AMD diagnosis. The primary exposure was metformin use analyzed as either active or prior use or cumulative metformin dosage over the study period. A time updating Cox proportional hazard regression was used to estimate the hazard ratio of dAMD incidence with metformin exposure.

RESULTS

Among 1,007,226 diabetic enrollees, 53.3% were female and 66.4% were white with a mean hemoglobin A1c of 6.8%. Of eligible enrollees, 166,115 (16.5%) were taking metformin at the index date. Over the study period, 29,818 (3.0%) participants developed dAMD. In the active versus prior use of metformin model, active use conferred an increased hazard of developing dAMD (HR, 1.08; 95% CI, 1.04-1.12) while prior use had a decreased hazard (HR, 0.95; 95% CI 0.92-0.98). The cumulative metformin dosage model showed a significant trend toward increased hazard of dAMD incidence with increasing cumulative dosage (p < 0.001), with the lowest dosage quartile having decreased hazard of dAMD incidence (HR, 0.95; 95% CI, 0.91-0.99) and the highest having increased hazard (HR, 1.07; 95% CI, 1.01-1.13).

CONCLUSIONS

Small, conflicting associations between metformin exposure and development of dAMD were observed depending on cumulative dosage and whether drug use was active, suggesting metformin did not substantially affect the development of dAMD.

Birth Weight Is a Significant Predictor of Retinal Nerve Fiber Layer Thickness at 36 Weeks Postmenstrual Age in Preterm Infants

PURPOSE

To assess retinal nerve fiber layer (RNFL) thickness in preterm infants.

DESIGN

Prospective observational study.

METHODS

We imaged 83 awake infants (159 eyes) at 36 ± 1 weeks postmenstrual age (defined as the time elapsed between the first day of the last maternal menstrual period and the time at imaging) using a handheld optical coherence tomography (OCT) system at the bedside. Blinded graders semi-automatically segmented RNFL in the papillomacular bundle (-15 to +15° relative to the fovea-optic nerve axis). We correlated RNFL thickness and 7 characteristics of interest (sex, race, ethnicity, gestational age, birth weight, stage of retinopathy at prematurity, and presence of pre-plus or plus disease) via univariable and multivariable regressions.

RESULTS

RNFL was 3.4 μm thicker in the right eyes than in the left eyes (P < .001). Among 7 characteristics, birth weight was the only independent predictor of RNFL thickness (P < .001). A 250-g increase in birth weight was associated with 5.2 μm (95% confidence interval: 3.3-7.0) increase in RNFL thickness. Compared with very preterm infants, extremely preterm infants had thinner RNFL (58.0 ± 10.7 μm vs 63.4 ± 10.7 μm, P = .03), but the statistical significance disappeared after adjustment for birth weight (P = .25). RNFL thickness was 11.2 μm thinner in extremely low birth weight infants than in very low birth weight infants (55.5 ± 8.3 μm vs. 66.7 ± 10.2 μm; P < .001). The difference remained statistically significant after adjustment for gestational age.

CONCLUSION

Birth weight is a significant independent predictor of RNFL thickness near birth, implying that the retinal ganglion cells reserve is affected by intrauterine processes that affect birth weight.

Repeatability and Reproducibility of Axial and Lateral Measurements on Handheld Optical Coherence Tomography Systems Compared with Tabletop System

Purpose

To compare the repeatability and reproducibility of axial and lateral retinal measurements using handheld optical coherence tomography (OCT) systems and a tabletop OCT system.

Methods

Graders measured central foveal thickness (CFT), optic nerve-to-fovea distance (OFD), and retinal nerve fiber layer (RNFL) thickness on OCT scans of the right eye of 10 healthy adults. Three OCT systems were used: handheld Leica Envisu, investigational handheld swept-source OCT (UC3), and Heidelberg Spectralis tabletop system. All eyes were imaged five times with each OCT system by each of two imagers. A components of variance analysis provided estimates of repeatability (variation due to random error) and reproducibility (variation due to imager, grader, and random error) expressed as standard deviation and (coefficient of variation %).

Results

Repeatability of CFT (µm) for Envisu, UC3, and Spectralis was 5.9 (2.6%), 6.9 (2.9%), and 4.7 (2.1%), and the reproducibility was 6.1 (2.7%), 7.3 (3.1%), and 4.7 (2.1%), respectively. The repeatability of OFD (mm) was 0.13 (2.9%), 0.10 (2.3%), and 0.07 (1.6%), and the reproducibility was 0.13 (3.0%), 0.10 (2.3%), and 0.07 (1.6%,) respectively. The repeatability for RNFL thickness (µm) for Envisu, UC3, and Spectralis was 4.3 (7.8%), 2.7 (5.4%), and 2.9 (4.9%), and the reproducibility was 4.5 (8.3%), 2.9 (5.8%), and 2.9 (4.9%), respectively.

Conclusions

All three OCT systems had good repeatability and reproducibility with coefficients of variation of less than 3.5% for CFT and OFD measurements, and less than 8.5% for RNFL thickness.

Translational Relevance

Our findings inform the repeatability and reproducibility of retinal axial and lateral measurements on handheld OCT and are useful for both clinical research and patient care.

Macular OCT Characteristics at 36 Weeks' Postmenstrual Age in Infants Examined for Retinopathy of Prematurity

PURPOSE

To report our ability to capture,-grade reliably, and analyze bedside macular OCT images from preterm infants and relate OCT findings to biological factors and retinopathy of prematurity (ROP) status at a single time window in the Study of Eye Imaging in Preterm Infants (BabySTEPS).

DESIGN

Prospective, observational study.

PARTICIPANTS

Preterm infants eligible for ROP screening with parental consent for research and a 36 ± 1 weeks' postmenstrual age (PMA) visit.

METHODS

We imaged both eyes of preterm infants with an investigational noncontact, handheld swept-source (SS) OCT at the time of clinical ROP examinations. Macular OCT features and layer thicknesses for untreated eyes of infants at 36 ± 1 weeks' PMA were compared with demographic data and clinical ROP examination performed by experts. Statistical analyses accounted for the use of both eyes of infants.

MAIN OUTCOME MEASURES

Macular OCT features and layer thicknesses, gender, race or ethnicity, gestational age, birth weight, ROP stage, and plus disease.

RESULTS

We captured macular OCT from 169 eyes (1 eye excluded because of prior ROP treatment) at 36 ± 1 weeks' PMA. The quality of OCT volumes was excellent in 33 eyes (19%), acceptable in 112 eyes (67%), poor in 24 eyes (14%), and unusable in 0 eyes (0%). Macular edema was present in 60% of eyes and was bilateral in 82% of infants with edema. At the fovea, retinal and inner nuclear layer thickness increased with edema severity: 183 ± 36 μm and 51 ± 27 μm in mild (16% of eyes), 308 ± 57 μm and 163 ± 53 μm in moderate (25%), and 460 ± 76 μm and 280 ± 83 μm in severe edema (12%), respectively. With an increase in ROP stage from 0 to 2, the mean ± standard deviation retinal thickness at the fovea increased from 227± 124 μm to 297 ± 99 μm (P < 0.001). The choroid was thinner, 155 ± 72 μm, with preplus or plus disease versus without, 236 ± 79 μm (P = 0.04), whereas retinal thickness did not vary.

CONCLUSIONS

We demonstrated the reliability of methods and the prevalence of OCT findings in preterm infants enrolled in BabySTEPS at a single time point of 36 ± 1 weeks' PMA. Variations in layer thicknesses in infants at this time point may reflect abnormalities resulting from delay in foveal development that may be impacted by macular edema, ROP, or both.

Visual conditions affecting eye growth alter diurnal levels of vitreous DOPAC

In chicks, the diurnal patterns of retinal dopamine synthesis and release are associated with refractive development. To assess the within-day patterns of dopamine release, we assayed vitreal levels of DOPAC (3,4-dihydroxyphenylacetic acid) using high performance liquid chromatography with electrochemical detection, at 4-h intervals over 24 h in eyes with experimental manipulations that change ocular growth rates. Chicks were reared under a 12 h light/12 h dark cycle; experiments began at 12 days of age. Output was assessed by modelling using the robust variance structure of Generalized Estimating Equations. Continuous spectacle lensdefocus or form deprivation: One group experienced non-restricted visual input to both eyes and served as untreated "normal" controls. Three experimental cohorts underwent monocular visual alterations known to alter eye growth and refraction: wearing a diffuser, a negative lens or a positive lens. After one full day of device-wear, chicks were euthanized at 4-h intervals over 24 h (8 birds per time/condition). Brief hyperopic defocus: Chicks wore negative lenses for only 2 daily hours either in the morning (starting at ZT 0; n = 16) or mid-day (starting at ZT 4; n = 8) for 3 days. Vitreal DOPAC was assayed. In chicks with bilateral non-restricted vision, or with continuous defocus or form-deprivation, there was a diurnal variation in vitreal DOPAC levels for all eyes (p < 0.001 for each). In normal controls, DOPAC was highest during the daytime, lowest at night, and equivalent for both eyes. In experimental groups, regardless of whether experiencing a growth stimulatory input (diffuser; negative lens) or growth inhibitory input (positive lens), DOPAC levels were reduced compared both to fellow eyes and to those of normal controls (p < 0.001 for each). These diurnal variations in vitreous DOPAC levels under different visual conditions indicate a complexity for dopaminergic mechanisms in refractive development that requires further study.

Visual Image Quality Impacts Circadian Rhythm-Related Gene Expression in Retina and in Choroid: A Potential Mechanism for Ametropias

Purpose

Stimulated by evidence implicating diurnal/circadian rhythms and light in refractive development, we studied the expression over 24 hours of selected clock and circadian rhythm-related genes in retina/retinal pigment epithelium (RPE) and choroid of experimental ametropias in chicks.

Methods

Newly hatched chicks, entrained to a 12-hour light/dark cycle for 12 to 14 days, either experienced nonrestricted vision OU (i.e., in both eyes) or received an image-blurring diffuser or a minus 10-diopter (D) or a plus 10-D defocusing lens over one eye. Starting 1 day later and at 4-hour intervals for 24 hours, the retina/RPE and choroid were separately dissected. Without pooling, total RNA was extracted, converted to cDNA, and assayed by quantitative PCR for the expression of the following genes: Opn4m, Clock, Npas2, Per3, Cry1, Arntl, and Mtnr1a.

Results

The expression of each gene in retina/RPE and in choroid of eyes with nonrestricted vision OU varied over 24 hours, with equal levels OU for most genes and times. Altered visual input influenced gene expression in complex patterns that varied by gene, visual input, time, and eye, affecting experimental eyes with altered vision and also contralateral eyes with nonrestricted vision.

Discussion

Altering visual input in ways known to induce ametropias alters the retinal/RPE and choroidal expression of circadian rhythm-related genes, further linking circadian biology with eye growth regulation. While further investigations are needed, studying circadian processes may help understand refractive mechanisms and the increasing myopia prevalence in contemporary societies where lighting patterns can desynchronize endogenous rhythms from the natural environmental light/dark cycle.

Comparison of the Iowa Reference Algorithm to the Heidelberg Spectralis optical coherence tomography segmentation algorithm

For spectral-domain optical coherence tomography (SD-OCT) studies of neurodegeneration, it is important to understand how segmentation algorithms differ in retinal layer thickness measurements, segmentation error locations and the impact of manual correction. Using macular SD-OCT images of frontotemporal degeneration patients and controls, we compare the individual and aggregate retinal layer thickness measurements provided by two commonly used algorithms, the Iowa Reference Algorithm and Heidelberg Spectralis, with manual correction of significant segmentation errors. We demonstrate small differences of most retinal layer thickness measurements between these algorithms. Outer sectors of the Early Treatment Diabetic Retinopathy Study grid require a greater percent of eyes to be corrected than inner sectors of the retinal nerve fiber layer (RNFL). Manual corrections affect thickness measurements mildly, resulting in at most a 5% change in RNFL thickness. Our findings can inform researchers how to best use different segmentation algorithms when comparing retinal layer thicknesses.

Childhood adversity impact on gut microbiota and inflammatory response to stress during pregnancy

BACKGROUND

Adverse childhood experiences (ACEs), such as abuse or chronic stress, program an exaggerated adult inflammatory response to stress. Emerging rodent research suggests that the gut microbiome may be a key mediator in the association between early life stress and dysregulated glucocorticoid-immune response. However, ACE impact on inflammatory response to stress, or on the gut microbiome, have not been studied in human pregnancy, when inflammation increases risk of poor outcomes. The aim of this study was to assess the relationships among ACE, the gut microbiome, and cytokine response to stress in pregnant women.

METHODS

Physically and psychiatrically healthy adult pregnant women completed the Adverse Childhood Experiences Questionnaire (ACE-Q) and gave a single stool sample between 20 and 26 weeks gestation. Stool DNA was isolated and 16S sequencing was performed. Three 24-hour food recalls were administered to assess dietary nutrient intake. A subset of women completed the Trier Social Stress Test (TSST) at 22-34 weeks gestation; plasma interleukin-6 (IL-6), interleukin-1β (IL-1β), high sensitivity C-reactive protein (hsCRP), tumor necrosis factor α (TNF-α), and cortisol were measured at four timepoints pre and post stressor, and area under the curve (AUC) was calculated.

RESULTS

Forty-eight women completed the ACE-Q and provided stool; 19 women completed the TSST. Women reporting 2 or more ACEs (high ACE) had greater differential abundance of gut Prevotella than low ACE participants (q = 5.7 × 10^-13). Abundance of several gut taxa were significantly associated with cortisol, IL-6, TNF-α and CRP AUCs regardless of ACE status. IL-6 response to stress was buffered among high ACE women with high intake of docosahexaenoic acid (DHA) (p = 0.03) and eicosapentaenoic acid (EPA) (p = 0.05).

DISCUSSION

Our findings suggest that multiple childhood adversities are associated with changes in gut microbiota composition during pregnancy, and such changes may contribute to altered inflammatory and glucocorticoid response to stress. While preliminary, this is the first study to demonstrate an association between gut microbiota and acute glucocorticoid-immune response to stress in a clinical sample. Finally, exploratory analyses suggested that high ACE women with high dietary intake of ω-3 polyunsaturated fatty acids (PUFAs) had a dampened inflammatory response to acute stress, suggesting potentially protective effects of ω-3s in this high-risk population. Given the adverse effects of inflammation on pregnancy and the developing fetus, mechanisms by which childhood adversity influence the gut-brain axis and potential protective factors such as diet should be further explored.

Reproducibility of 2D GluCEST in healthy human volunteers at 7 T

PURPOSE

To investigate the reproducibility of gray and white matter glutamate contrast of a brain slice among a small group of healthy volunteers by using the 2D single-slice glutamate CEST (GluCEST) imaging technique.

METHODS

Six healthy volunteers were scanned multiple times for within-day and between-day reproducibility. One more volunteer was scanned for within-day reproducibility at 7T MRI. Glutamate CEST contrast measurements were calculated for within subjects and among the subjects and the coefficient of variations are reported.

RESULTS

The GluCEST measurements were highly reproducible in the gray and white matter area of the brain slice, whether it was within-day or between-day with a coefficient of variation of less than 5%.

CONCLUSION

This preliminary study in a small group of healthy volunteers shows a high degree of reproducibility of GluCEST MRI in brain and holds promise for implementation in studying age-dependent changes in the brain.

Experimental studies of the NaCs 5(3)Π0 and 1(a)3Σ+ states

We report high resolution measurements of 372 NaCs 5(3)Π(0)(v, J) ro-vibrational level energies in the range 0 ≤ v ≤ 22. The data have been used to construct NaCs 5(3)Π(0) potential energy curves using the Rydberg-Klein-Rees and inverted perturbation approximation methods. Bound-free 5(3)Π(0)(v, J) → 1(a)(3)Σ(+) emission has also been measured, and is used to determine the repulsive wall of the 1(a)(3)Σ(+) state and the 5(3)Π(0) → 1(a)(3)Σ(+) relative transition dipole moment function. Hyperfine structure in the 5(3)Π(0) state has not been observed in this experiment. This null result is explained using a simple vector coupling model.

Inductive sustainment of a field-reversed configuration stabilized by shaping, magnetic diffusion, and finite-Larmor-radius effects

Oblate field-reversed configuration (FRC) plasmas are sustained for up to 350 micros, or approximately 15 poloidal flux-confinement times, in the magnetic reconnection experiment. The diamagnetic equilibrium is maintained in argon plasmas as a balance of an inward pinch and outward diffusion. Numerical and analytic models show that the observed stability is provided by a combination of plasma shaping, magnetic diffusion, and finite-Larmor radius effects. FRCs formed with lighter ions, which benefit less from these stabilizing effects, succumb to rapid instability and cannot be sustained.