June 2020

Kang JH, VoPham T, Laden F, Rosner BA, Wirostko B, Ritch R, Wiggs JL, Qureshi A, Nan H, Pasquale LR. Cohort Study of Nonmelanoma Skin Cancer and the Risk of Exfoliation Glaucoma. J Glaucoma 2020;29(6):448-455.Abstract
PRECIS: In a cohort study of 120,307 participants with 25+ years of follow-up, a history of nonmelanoma skin cancer (NMSC) was associated with a 40% higher exfoliation glaucoma (XFG) risk. PURPOSE: The purpose of this study was to evaluate the relationship between NMSC (a marker of ultraviolet radiation exposure) and XFG. METHODS: We performed a cohort study of US women (n=79,102; 1980-2014) and men (n=41,205; 1986-2014), aged 40+ years and at risk for glaucoma who reported eye examinations. From 1984 (women)/1988 (men), we asked about basal cell carcinoma or squamous cell carcinoma history separately; in prior years, we asked about any NMSC history in a single question. Squamous cell carcinoma was confirmed with histopathology reports while basal cell carcinoma and any early (<1984/<1988) NMSC history was self-reported. Incident XFG cases (362 women and 83 men) were confirmed with medical records. Using pooled data, we estimated multivariable-adjusted relative risks [MVRRs; 95% confidence intervals (CIs)] with Cox proportional hazards models that were stratified by age (in mo), 2-year time period at risk and average lifetime residential latitude. RESULTS: In multivariable-adjusted analyses, we observed a 40% higher XFG risk with any NMSC history (MVRR=1.40; 95% CI=1.08-1.82); the association was observed even with 4 and 8-year lags in NMSC history. Also, the NMSC association was stronger in younger (below 65 y; MVRR=2.56; 95% CI=1.62-4.05) versus older participants (65 y and above; MVRR=1.25; 95% CI=0.94-1.66; P for interaction=0.01) and those living in the northern latitudes (≥42°N; MVRR=1.92; 95% CI=1.28-2.88) versus more southern latitudes (<42°N; MVRR=1.19; 95% CI=0.86-1.66; P for interaction=0.04). CONCLUSION: NMSC was associated with higher XFG risk, particularly among younger participants and those living in the Northern US.
Li LH, Lee JC-Y, Leung HH, Lam WC, Fu Z, Lo ACY. Lutein Supplementation for Eye Diseases. Nutrients 2020;12(6)Abstract
Lutein is one of the few xanthophyll carotenoids that is found in high concentration in the macula of human retina. As synthesis of lutein within the human body is impossible, lutein can only be obtained from diet. It is a natural substance abundant in egg yolk and dark green leafy vegetables. Many basic and clinical studies have reported lutein's anti-oxidative and anti-inflammatory properties in the eye, suggesting its beneficial effects on protection and alleviation of ocular diseases such as age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, myopia, and cataract. Most importantly, lutein is categorized as Generally Regarded as Safe (GRAS), posing minimal side-effects upon long term consumption. In this review, we will discuss the chemical structure and properties of lutein as well as its application and safety as a nutritional supplement. Finally, the effects of lutein consumption on the aforementioned eye diseases will be reviewed.
McKay TB, Serjersen H, Hjortdal J, Zieske JD, Karamichos D. Characterization of Tear Immunoglobulins in a Small-Cohort of Keratoconus Patients. Sci Rep 2020;10(1):9426.Abstract
Keratoconus (KC) is classically considered a non-inflammatory condition caused by central corneal thinning that leads to astigmatism and reduced visual acuity. Previous studies have identified increased systemic levels of pro-inflammatory factors, including interleukin-6, tumor necrosis factor-α, and matrix metalloproteinase-9, suggesting that KC may have an inflammatory component in at least a subset of patients. In this study, we evaluated the levels of different immunoglobulins (light and heavy chains) based on Ig α, Ig λ, Ig κ, Ig µ, and Ig heavy chain subunits in non-KC tears (n = 7 control individuals) and KC tears (n = 7 KC patients) using tandem-liquid chromatography mass spectrometry. The most abundant Ig heavy chains detected in both control individuals and KC patients were Ig α-1 and Ig α-2 likely correlating to the higher IgA levels reported in human tears. We identified significant differences in immunoglobulin κ-chain V-II levels in KC patients compared to control individuals with no significant difference in Ig κ/Ig λ ratios or heavy chain levels. Our study supports previous findings suggesting that KC possesses a systemic component that may contribute to the KC pathology. Further studies are required to define causality and establish a role for systemic immune system-dependent factors and pro-inflammatory processes in KC development or progression.
Moustafa GA, Topham AK, Aronow ME, Vavvas DG. Paediatric ocular adnexal lymphoma: a population-based analysis. BMJ Open Ophthalmol 2020;5(1):e000483.Abstract
Objective: To investigate the incidence, clinicopathological characteristics and survival of ocular adnexal lymphoma (OAL) in the paediatric population. Methods and analysis: In this retrospective case series, the Surveillance, Epidemiology and End Results database was accessed to identify individuals with OAL ≤18 years of age, diagnosed between 1973 and 2015. OAL located in the eyelid, conjunctiva, lacrimal apparatus and orbit were included. Main outcome measures were the age-adjusted incidence rates (IRs) per 1 000 000 population at risk (calculated for the period 2000-2015) and descriptive statistics of demographic and clinicopathological features. Results: The IR of paediatric OAL was 0.12 (95% CI 0.08 to 0.16) per 1 000 000. Males (0.15; 95% CI 0.10 to 0.22) and blacks (0.24; 95% CI 0.13 to 0.42) had a higher tendency for OAL development. A total of 55 tumours in 54 children were identified. The majority were localised (78.4%), conjunctival (49.1%) lymphomas. Extranodal marginal zone lymphoma (EMZL, 45.5%, n=25) was the most frequent subtype, followed by diffuse large B-cell lymphoma (DLBCL, 9.1%, n=5), B lymphoblastic lymphoma (7.3%, n=4), follicular lymphoma (5.5%, n=3), Burkitt lymphoma (5.5%, n=3), anaplastic large cell lymphoma (ALCL, 3.6%, n=2), small lymphocytic lymphoma (1.8%, n=1), diffuse large B-cell lymphoma, immunoblastic (1.8%, n=1) and panniculitis-like T-cell lymphoma (1.8%, n=1). Localised, low-grade, conjunctival lymphomas were frequently treated with complete excision with or without radiation, while high-grade and distant tumours usually received chemotherapy. Only 29.1% of paediatric OAL cases were treated with radiation. Three out of five (60%) patients with DLBCL died of lymphoma at a median follow-up of 21 (range 10-86) months, and 1 out of 2 (50%) patients with ALCL died of lymphoma at 23 months from diagnosis. Conclusion: OAL in the paediatric population is rare. The majority of OAL are EMZL and are characterised by excellent prognosis. The histological subtype was found to be the main predictor of outcome with cancer-specific deaths observed in patients with DLBCL and ALCL.
Porporato N, Baskaran M, Tun TA, Sultana R, Tan M, Quah JHM, Allen JC, Perera S, Friedman DS, Cheng CY, Aung T. Understanding diagnostic disagreement in angle closure assessment between anterior segment optical coherence tomography and gonioscopy. Br J Ophthalmol 2020;104(6):795-799.Abstract
BACKGROUND/AIMS: Although being a more objective tool for assessment and follow-up of angle closure, reliability studies have reported a moderate diagnostic performance for anterior segment optical coherence tomography (OCT) technologies when comparing with gonioscopy as the reference standard. We aim to determine factors associated with diagnostic disagreement in angle closure when assessed by anterior segment swept source OCT (SS-OCT, CASIA SS-1000; Tomey, Nagoya, Japan) and gonioscopy. METHODS: Cross-sectional study. A total of 2027 phakic subjects aged ≥50 years, with no relevant previous ophthalmic history, were consecutively recruited from a community polyclinic in Singapore. Gonioscopy and SS-OCT (128 radial scans) for the entire circumference of the angle were performed for each subject. A two-quadrant closed gonioscopic definition was used. On SS-OCT images, angle closure was defined as iridotrabecular contact (ITC) to the extent of ≥35%, ≥50% and ≥75% of the circumferential angle. Diagnostic disagreements between both methods, that is, false positives or overcalls and false negatives or undercalls were defined, respectively, as gonioscopic open/closed angles inversely assessed as closed/open by SS-OCT. RESULTS: Two hundred and seventy-two (14.7%) resulted in overcall results (false positives) when ≥50% of the angle circumference was closed using SS-OCT. These eyes had significantly wider (anterior chamber width, 11.7 vs 11.6 mm, p<0.001) and deeper (anterior chamber depth (ACD), 2.4 vs 2.2 mm, p<0.001) anterior chambers than eyes assessed by both methods as closed (true positives). Deeper ACD (OR 9.31) and lower lens vault (LV) (OR 0.04) were significantly associated with a false positive diagnosis in the multivariate analysis. Most of these cases had short (52.6%) or irregular (39%) ITC in SS-OCT images. CONCLUSIONS: We found that anterior chamber dimensions, determined by ACD and LV, were factors significantly associated with diagnostic disagreement between anterior segment SS-OCT and gonioscopy in angle closure assessment.
Seminario-Vidal L, Kroshinsky D, Malachowski SJ, Sun J, Markova A, Beachkofsky TM, Kaffenberger BH, Ergen EN, Mauskar M, Bridges A, Calhoun C, Cardones AR, Chen ST, Chodosh J, Cotliar J, Davis MDP, DeNiro KL, Dominguez AR, Eljure-Téllez J, Femia A, Fox LP, Guda A, Mitchell C, Mostaghimi A, Ortega-Loayza AG, Owen C, Pasieka H, Rahnama-Moghadam S, Saeed HN, Saunderson RB, Shanbhag S, Sharon VR, Strowd L, Venkatesh S, Wanat KA, Wetter DA, Worswick S, Micheletti RG. Society of Dermatology Hospitalists supportive care guidelines for the management of Stevens-Johnson syndrome/toxic epidermal necrolysis in adults. J Am Acad Dermatol 2020;82(6):1553-1567.Abstract
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening conditions with high morbidity and mortality. Supportive care management of SJS/TEN is highly variable. A systematic review of the literature was performed by dermatologists, ophthalmologists, intensivists, and gynecologists with expertise in SJS/TEN to generate statements for supportive care guideline development. Members of the Society of Dermatology Hospitalists with expertise in SJS/TEN were invited to participate in a modified, online Delphi-consensus. Participants were administered 9-point Likert scale questionnaires regarding 135 statements. The RAND/UCLA Appropriateness Method was used to evaluate and select proposed statements for guideline inclusion; statements with median ratings of 6.5 to 9 and a disagreement index of ≤1 were included in the guideline. For the final round, the guidelines were appraised by all of the participants. Included are an evidence-based discussion and recommendations for hospital setting and care team, wound care, ocular care, oral care, urogenital care, pain management, infection surveillance, fluid and electrolyte management, nutrition and stress ulcer prophylaxis, airway management, and anticoagulation in adult patients with SJS/TEN.
Shoshany TN, Michalak SM, Chinn RN, Staffa SJ, Hunter DG. Evaluating Amblyopia Treatment Success Using the American Academy of Ophthalmology IRIS50 Measures. Ophthalmology 2020;127(6):836-838.
Shu DY, Butcher E, Saint-Geniez M. EMT and EndMT: Emerging Roles in Age-Related Macular Degeneration. Int J Mol Sci 2020;21(12)Abstract
Epithelial-mesenchymal transition (EMT) and endothelial-mesenchymal transition (EndMT) are physiological processes required for normal embryogenesis. However, these processes can be hijacked in pathological conditions to facilitate tissue fibrosis and cancer metastasis. In the eye, EMT and EndMT play key roles in the pathogenesis of subretinal fibrosis, the end-stage of age-related macular degeneration (AMD) that leads to profound and permanent vision loss. Predominant in subretinal fibrotic lesions are matrix-producing mesenchymal cells believed to originate from the retinal pigment epithelium (RPE) and/or choroidal endothelial cells (CECs) through EMT and EndMT, respectively. Recent evidence suggests that EMT of RPE may also be implicated during the early stages of AMD. Transforming growth factor-beta (TGFβ) is a key cytokine orchestrating both EMT and EndMT. Investigations in the molecular mechanisms underpinning EMT and EndMT in AMD have implicated a myriad of contributing factors including signaling pathways, extracellular matrix remodelling, oxidative stress, inflammation, autophagy, metabolism and mitochondrial dysfunction. Questions arise as to differences in the mesenchymal cells derived from these two processes and their distinct mechanistic contributions to the pathogenesis of AMD. Detailed discussion on the AMD microenvironment highlights the synergistic interactions between RPE and CECs that may augment the EMT and EndMT processes in vivo. Understanding the differential regulatory networks of EMT and EndMT and their contributions to both the dry and wet forms of AMD can aid the development of therapeutic strategies targeting both RPE and CECs to potentially reverse the aberrant cellular transdifferentiation processes, regenerate the retina and thus restore vision.
Silva RNE, Taniguchi EV, Cruzat A, Paschalis EI, Pasquale LR, Colby KA, Dohlman CH, Chodosh J, Shen LQ. Angle Anatomy and Glaucoma in Patients With Boston Keratoprosthesis. Cornea 2020;39(6):713-719.Abstract
PURPOSE: To quantitatively analyze the angle anatomy in eyes with a Boston type 1 keratoprosthesis (KPro) using anterior segment optical coherence tomography (AS-OCT) and to assess the diagnostic ability of AS-OCT in KPro-associated glaucoma. METHODS: AS-OCT (RTVue) images from KPro eyes with and without glaucoma were reviewed. The angle opening distance at 500 μm from the scleral spur (AOD500), trabecular-iris angle at 500 μm from the scleral spur (TIA500), and trabecular-iris surface area at 500 μm from the scleral spur (TISA500) were measured by 2 observers masked to the diagnosis. The measurements for each visible quadrant were compared between KPro eyes with and without glaucoma. RESULTS: Twenty-two eyes with glaucoma and 17 eyes without glaucoma from 39 patients with KPro were included. Of the 4 quadrants imaged, the temporal angle was the most visible (79.5%) and angle measurements of the temporal quadrant were the only ones that differentiated the 2 groups: the mean AOD500, TIA500, and TISA500 were significantly lower in KPro eyes with glaucoma than without glaucoma (388.2 ± 234.4 μm vs. 624.5 ± 310.5 μm, P = 0.02; 26.1 ± 14.0 degrees vs. 39.1 ± 17.1 degrees, P = 0.03; and 0.15 ± 0.09 mm vs. 0.23 ± 0.12 mm, P = 0.03; respectively). The highest area under the receiver operating characteristic curve for detecting glaucoma was 0.75 for temporal TIA500 (95% confidence interval 0.57-0.94, P = 0.02) with 50% specificity at 80% of sensitivity and a cutoff value of 37 degrees. CONCLUSIONS: The temporal angle was the most visible on AS-OCT in eyes with a KPro. Significant narrowing of the temporal angle detected on AS-OCT was associated with glaucoma in these eyes.
Sobrin L, Pistilli M, Dreger K, Kothari S, Khachatryan N, Artornsombudh P, Pujari SS, Foster SC, Jabs DA, Nussenblatt RB, Rosenbaum JT, Levy-Clarke GA, Sen NH, Suhler EB, Thorne JE, Bhatt NP, Kempen JH, for Group SITEDCSR. Factors Predictive of Remission of Chronic Anterior Uveitis. Ophthalmology 2020;127(6):826-834.Abstract
PURPOSE: To estimate the incidence of medication-free remission of chronic anterior uveitis and identify predictors thereof. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients diagnosed with anterior uveitis of longer than 3 months' duration followed up at United States tertiary uveitis care facilities. METHODS: Estimation of remission incidence and identification of associated predictors used survival analysis. MAIN OUTCOME MEASURES: Incidence of medication-free remission. For the primary analysis, remission was defined as inactive uveitis while off treatment at all visits spanning an interval of at least 90 days or-for patients who did not return for follow-up after 90 days-remaining inactive without receiving suppressive medications at all of the last visits. Association of factors potentially predictive of medication-free remission was also studied. RESULTS: Two thousand seven hundred ninety-five eyes of 1634 patients with chronic anterior uveitis were followed up over 7936 eye-years (4676 person-years). The cumulative medication-free, person-year remission incidence within 5 years was 32.7% (95% confidence interval [CI], 30.4%-35.2%). Baseline clinical factors predictive of reduced remission incidence included longer duration of uveitis at presentation (for 2 to 5 years vs. less than 6 months: adjusted hazard ratio [aHR], 0.61; 95% CI, 0.44-0.83), bilateral uveitis (aHR, 0.75; 95% CI, 0.59-0.96), prior cataract surgery (aHR, 0.70; 95% CI 0.56-0.88), and glaucoma surgery (aHR, 0.63; 95% CI, 0.45-0.90). Two time-updated characteristics were also predictive of reduced remission incidence: keratic precipitates (aHR, 0.36; 95% CI, 0.21-0.60) and synechiae (aHR, 0.62; 95% CI, 0.41-0.93). Systemic diagnosis with juvenile idiopathic arthritis and spondyloarthropathy were also associated with reduced remission incidence. Older age at presentation was associated with higher incidence of remission (for age ≥40 years vs. <40 years: aHR, 1.29; 95% CI, 1.02-1.63). CONCLUSIONS: Approximately one third of patients with chronic anterior uveitis remit within 5 years. Longer duration of uveitis, younger age, bilateral uveitis, prior cataract surgery, glaucoma surgery, presence of keratic precipitates and synechiae, and systemic diagnoses of juvenile idiopathic arthritis and spondyloarthropathy predict reduced remission incidence; patients with these factors should be managed taking into account the higher probability of a longer disease course.
Soh YQ, Kocaba V, Weiss JS, Jurkunas UV, Kinoshita S, Aldave AJ, Mehta JS. Corneal dystrophies. Nat Rev Dis Primers 2020;6(1):46.Abstract
Corneal dystrophies are broadly defined as inherited disorders that affect any layer of the cornea and are usually progressive, bilateral conditions that do not have systemic effects. The 2015 International Classification of Corneal Dystrophies classifies corneal dystrophies into four classes: epithelial and subepithelial dystrophies, epithelial-stromal TGFBI dystrophies, stromal dystrophies and endothelial dystrophies. Whereas some corneal dystrophies may result in few or mild symptoms and morbidity throughout a patient's lifetime, others may progress and eventually result in substantial visual and ocular disturbances that require medical or surgical intervention. Corneal transplantation, either with full-thickness or partial-thickness donor tissue, may be indicated for patients with advanced corneal dystrophies. Although corneal transplantation techniques have improved considerably over the past two decades, these surgeries are still associated with postoperative risks of disease recurrence, graft failure and other complications that may result in blindness. In addition, a global shortage of cadaveric corneal graft tissue critically limits accessibility to corneal transplantation in some parts of the world. Ongoing advances in gene therapy, regenerative therapy and cell augmentation therapy may eventually result in the development of alternative, novel treatments for corneal dystrophies, which may substantially improve the quality of life of patients with these disorders.
Ung L, Wang Y, Vangel M, Davies EC, Gardiner M, Bispo PJM, Gilmore MS, Chodosh J. Validation of a Comprehensive Clinical Algorithm for the Assessment and Treatment of Microbial Keratitis. Am J Ophthalmol 2020;214:97-109.Abstract
PURPOSE: To validate a comprehensive clinical algorithm for the assessment and treatment of microbial keratitis (MK). DESIGN: Retrospective cohort study. METHODS: The "1, 2, 3 Rule" for the initial management of MK was conceived by Vital and associates in 2007 to inform the decision as to when to perform corneal cultures. The rule is invoked when any 1 of 3 clinical parameters is met: ≥1+ anterior chamber cells, ≥2 mm infiltrate, or infiltrate ≤3 mm distance from the corneal center. When the rule is met, we added the mandatory use of fortified topical antibiotics after cultures are obtained. We compared outcomes of cases presenting to Massachusetts Eye and Ear 2 years before (Group I, n = 665) and after (Group II, n = 767) algorithm implementation. The primary composite outcome was a vision-threatening complication, such as corneal perforation. RESULTS: At a median follow-up of 67.0 and 60.0 days, respectively, 172 patients experienced a vision-threatening complication (Group I, 12.9% vs Group II, 11.2%, P = .51). While the algorithm codified conventional management practice at either end of disease severity, the effect of algorithm-augmented care was best appreciated in patients with lesions satisfying only 1 criterion. In this group, there was an increase in the proportion of patients undergoing culture at presentation (54.6% vs 67.7%, P = .006), fortified antibiotic prescription (29.7% vs 53.9%, P < .001), and reduction in vision-threatening complications (9.7% vs 1.8%, P = .001). The proportion of patients who were not cultured at presentation but later required culturing decreased (13.4% vs 5.1%, P = .001), as did patients who did not meet any criteria but were nonetheless cultured (23.9% vs 8.5%, P < .001). Multiple logistic regression showed that all algorithm parameters were independently associated with outcome: ≥1+ anterior chamber cells (odds ratio [OR] 1.66, 95% confidence interval 1.09-2.52); ≥2 mm infiltrate (OR 4.74, 2.68-8.40); and ≤3 mm from corneal center (OR 2.82, 1.85-4.31), confirmed with comparison to a bootstrapped sample (n = 10,000). CONCLUSIONS: The implementation of this algorithm reduced vision-threatening complications for patients with lesions satisfying only 1 criterion, arguably the most difficult patients in whom to judge disease severity. Implementation also led to a decrease in patients receiving unnecessary care.
Valdes LM, Sobrin L. Uveitis Therapy: The Corticosteroid Options. Drugs 2020;80(8):765-773.Abstract
Uveitis is characterized by intraocular inflammation involving the uveal tract; its etiologies generally fall into two broad categories: autoimmune/inflammatory or infectious. Corticosteroids  are a powerful and important class of medications ubiquitous in the treatment of uveitis. They may be given systemically or locally, in the form of topical drops, periocular injection, intravitreal suspension, or intravitreal implant. This review describes each of the currently available corticosteroid treatment options for uveitis, including favorable and unfavorable characteristics of each as well as applicable clinical trials. The main advantage of corticosteroids as a whole is their ability to quickly and effectively control inflammation early on in the course of uveitis. However, they can have serious side effects, whether localized to the eye (such as cataract and elevated intraocular pressure) or systemic (such as osteonecrosis and adrenal insufficiency) and in the majority of cases of uveitis are not an appropriate option for long-term therapy.
Vandenberghe LH. COVID-19: Gene Transfer to the Rescue?. Hum Gene Ther 2020;31(11-12):605-607.
Vasilikos I, Haas J, Teixeira GQ, Nothelfer J, Neidlinger-Wilke C, Wilke H-J, Seitz A, Vavvas DG, Zentner J, Beck J, Hubbe U, Mizaikoff B. Infrared attenuated total reflection spectroscopic surface analysis of bovine-tail intervertebral discs after UV-light-activated riboflavin-induced collagen crosslinking. J Biophotonics 2020;:e202000110.Abstract
The tensile strength of the intervertebral disc (IVD) is mainly maintained by collagen cross-links. Loss of collagen cross-linking combined with other age-related degenerative processes contributes to tissue weakening, biomechanical failure, disc herniation and pain. Exogenous collagen cross-linking has been identified as an effective therapeutic approach for restoring IVD tensile strength. The current state-of-the-art method to assess the extent of collagen cross-linking in tissues requires destructive procedures and high-performance liquid chromatography (HPLC). In this study, we investigated the utility of infrared attenuated total reflection (IR-ATR) spectroscopy as a non-destructive analytical strategy to rapidly evaluate the extent of UV-light-activated riboflavin (B2)-induced collagen crosslinking (UVA-CXL) in bovine IVD samples. Thirty five fresh bovine-tail IVD samples were equally divided into five treatment groups: (i) untreated, (ii) cell culture medium DMEM only, (iii) B2 only, (iv) UV-light only, and (v) UV-light-B2. A total of 674 measurements have been acquired, and were analyzed via partial least squares discriminant analysis. This classification scheme unambiguously identified individual classes with a sensitivity >91% and specificity >92%. The obtained results demonstrate that IR-ATR spectroscopy reliably differentiates between different treatment categories, and promises an excellent tool for potential in vivo, non-destructive, and real-time assessment of exogenous IVD crosslinking. This article is protected by copyright. All rights reserved.
Vongsachang H, Friedman DS, Inns A, Kretz AM, Mukherjee MR, Callan J, Wahl M, Repka MX, Collins ME. Parent and Teacher Perspectives on Factors Decreasing Participation in School-Based Vision Programs. Ophthalmic Epidemiol 2020;27(3):226-236.Abstract
: To examine factors decreasing participation in school-based vision programs from parent and teacher perspectives.: We conducted 41 semi-structured focus groups (20 parent groups, 21 teacher/staff groups), at 10 Baltimore and 11 Chicago public elementary and middle schools offering school-based vision programs. School-based vision programs provided vision screening, eye exams, and eyeglasses if needed. Focus groups ranged in size from 2-9 participants (median = 5). Sessions were recorded, transcribed, and coded through an iterative process to develop themes using inductive analysis.: Ninety parents and 117 teachers/staff participated. Participants identified five major factors decreasing participation in school-based vision programs: (1) challenges with the consent form, including distribution, collection, and literacy and language barriers; (2) having existing eye care; (3) misunderstandings about the program, especially related to cost and insurance; (4) difficulty raising parental awareness of the program; and (5) certain attitudes towards vision, eye care, and school-based programs, including low prioritization of eye care, mistrust of the program, fear of sharing private information, not believing their child needs glasses, and reluctance accepting 'subsidized' services.: Parents and teachers identified important structural barriers to participation (i.e., consent form challenges and low parental awareness) and specific reasons for non-participation (i.e., attitudes, misunderstanding of the program, existing eye care) in school-based vision programs. Effective strategies are needed to facilitate return of consent forms and promote awareness of school-based vision programs among parents. Programs should also target services towards those currently without access to eye care and increase awareness about paediatric vision needs.
Xiao W, Kreiman G. XDream: Finding preferred stimuli for visual neurons using generative networks and gradient-free optimization. PLoS Comput Biol 2020;16(6):e1007973.Abstract
A longstanding question in sensory neuroscience is what types of stimuli drive neurons to fire. The characterization of effective stimuli has traditionally been based on a combination of intuition, insights from previous studies, and luck. A new method termed XDream (EXtending DeepDream with real-time evolution for activation maximization) combined a generative neural network and a genetic algorithm in a closed loop to create strong stimuli for neurons in the macaque visual cortex. Here we extensively and systematically evaluate the performance of XDream. We use ConvNet units as in silico models of neurons, enabling experiments that would be prohibitive with biological neurons. We evaluated how the method compares to brute-force search, and how well the method generalizes to different neurons and processing stages. We also explored design and parameter choices. XDream can efficiently find preferred features for visual units without any prior knowledge about them. XDream extrapolates to different layers, architectures, and developmental regimes, performing better than brute-force search, and often better than exhaustive sampling of >1 million images. Furthermore, XDream is robust to choices of multiple image generators, optimization algorithms, and hyperparameters, suggesting that its performance is locally near-optimal. Lastly, we found no significant advantage to problem-specific parameter tuning. These results establish expectations and provide practical recommendations for using XDream to investigate neural coding in biological preparations. Overall, XDream is an efficient, general, and robust algorithm for uncovering neuronal tuning preferences using a vast and diverse stimulus space. XDream is implemented in Python, released under the MIT License, and works on Linux, Windows, and MacOS.
Xue Y, Razafsky D, Hodzic D, Kefalov VJ. Mislocalization of cone nuclei impairs cone function in mice. FASEB J 2020;Abstract
The nuclei of cone photoreceptors are located on the apical side of the outer nuclear layer (ONL) in vertebrate retinas. However, the functional role of this evolutionarily conserved localization of cone nuclei is unknown. We previously showed that Linkers of the Nucleoskeleton to the Cytoskeleton (LINC complexes) are essential for the apical migration of cone nuclei during development. Here, we developed an efficient genetic strategy to disrupt cone LINC complexes in mice. Experiments with animals from both sexes revealed that disrupting cone LINC complexes resulted in mislocalization of cone nuclei to the basal side of ONL in mouse retina. This, in turn, disrupted cone pedicle morphology, and appeared to reduce the efficiency of synaptic transmission from cones to bipolar cells. Although we did not observe other developmental or phototransduction defects in cones with mislocalized nuclei, their dark adaptation was impaired, consistent with a deficiency in chromophore recycling. These findings demonstrate that the apical localization of cone nuclei in the ONL is required for the timely dark adaptation and efficient synaptic transmission in cone photoreceptors.