Winter CC, He Z, Jacobi A. Axon Regeneration: A Subcellular Extension in Multiple Dimensions. Cold Spring Harb Perspect Biol 2021;Abstract
Axons are a unique cellular structure that allows for the communication between neurons. Axon damage compromises neuronal communications and often leads to functional deficits. Thus, developing strategies that promote effective axon regeneration for functional restoration is highly desirable. One fruitful approach is to dissect the regenerative mechanisms used by some types of neurons in both mammalian and nonmammalian systems that exhibit spontaneous regenerative capacity. Additionally, numerous efforts have been devoted to deciphering the barriers that prevent successful axon regeneration in the most regeneration-refractory system-the adult mammalian central nervous system. As a result, several regeneration-promoting strategies have been developed, but significant limitations remain. This review is aimed to summarize historic progression and current understanding of this exciting yet incomplete endeavor.
Ruan Y, Jiang S, Musayeva A, Pfeiffer N, Gericke A. Corneal Epithelial Stem Cells-Physiology, Pathophysiology and Therapeutic Options. Cells 2021;10(9)Abstract
In the human cornea, regeneration of the epithelium is regulated by the stem cell reservoir of the limbus, which is the marginal region of the cornea representing the anatomical and functional border between the corneal and conjunctival epithelium. In support of this concept, extensive limbal damage, e.g., by chemical or thermal injury, inflammation, or surgery, may induce limbal stem cell deficiency (LSCD) leading to vascularization and opacification of the cornea and eventually vision loss. These acquired forms of limbal stem cell deficiency may occur uni- or bilaterally, which is important for the choice of treatment. Moreover, a variety of inherited diseases, such as congenital aniridia or dyskeratosis congenita, are characterized by LSCD typically occurring bilaterally. Several techniques of autologous and allogenic stem cell transplantation have been established. The limbus can be restored by transplantation of whole limbal grafts, small limbal biopsies or by ex vivo-expanded limbal cells. In this review, the physiology of the corneal epithelium, the pathophysiology of LSCD, and the therapeutic options will be presented.
Chen Y, Dana R. Autoimmunity in dry eye disease - An updated review of evidence on effector and memory Th17 cells in disease pathogenicity. Autoimmun Rev 2021;20(11):102933.Abstract
The classic Th1/Th2 dogma has been significantly reshaped since the subsequent introduction of several new T helper cell subsets, among which the most intensively investigated during the last decade is the Th17 lineage that demonstrates critical pathogenic roles in autoimmunity and chronic inflammation - including the highly prevalent dry eye disease. In this review, we summarize current concepts of Th17-mediated disruption of ocular surface immune homeostasis that leads to autoimmune inflammatory dry eye disease, by discussing the induction, activation, differentiation, migration, and function of effector Th17 cells in disease development, highlighting the phenotypic and functional plasticity of Th17 lineage throughout the disease initiation, perpetuation and sustention. Furthermore, we emphasize the most recent advance in Th17 memory formation and function in the chronic course of dry eye disease, a major area to be better understood for facilitating the development of effective treatments in a broader field of autoimmune diseases that usually present a chronic course with recurrent episodes of flare in the target tissues or organs.
Laíns I, Wang JC, Cui Y, Katz R, Vingopoulos F, Staurenghi G, Vavvas DG, Miller JW, Miller JB. Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). Prog Retin Eye Res 2021;84:100951.Abstract
The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.
Douglas VP, Douglas KA, Cestari DM. Ophthalmic manifestations of dementing disorders. Curr Opin Ophthalmol 2021;32(6):515-520.Abstract
PURPOSE OF REVIEW: Dementia is a term for loss of memory, language, problem-solving, and other thinking abilities, which significantly interferes with daily life. Certain dementing conditions may also affect visual function. The eye is an accessible window to the brain that can provide valuable information for the early diagnosis of people who suffer from Alzheimer's disease, Parkinson's disease, dementia with Lewy bodies as well as from more rare causes of dementias, such as Creutzfeldt-Jacob and Huntington's diseases. Herein, we present the ocular manifestations of neurocognitive disorders focusing on the neuro-ophthalmic ones and further discuss potential ocular biomarkers that could help in early detection of these disorders. RECENT FINDINGS: Ophthalmic examination along with the recent developments in in-vivo testing have provided a strong foundation of useful knowledge about brain disorder in neurodegenerative diseases without the need for invasive studies. Currently, a number of visual measures, such as visual acuity, contrast sensitivity, pupil response, and saccades in addition to various ophthalmic tests, such as electroretinogram, visual evoked potential, optical coherence tomography (OCT), and OCT-angiography have been widely used and evaluated as potential biomarkers for different stages of dementia. SUMMARY: Ophthalmologic and neuro-ophthalmic evaluation is evolving as an important part of the early diagnosis and management of people with dementia. A particular focus on ocular biomarkers in dementing illnesses has arisen over the past few years and there are several promising measures and imaging tools that have been proposed as potential biomarkers for these diseases.
Genadry KC, Shrock C, O'Shea D, Vatsa R, Shah AS, Gise R, Lipsett SC. Traumatic Hyphema. J Emerg Med 2021;61(6):740-741.
Liou V, Yoon M. Comparative Incidence of Periocular Surgical Site Infections with Increased Surgical Mask Use during the COVID-19 Pandemic. Ocul Immunol Inflamm 2021;:1-6.Abstract
PURPOSE: To evaluate the effect of surgical mask use on infection rates for office-based periocular surgeries during the pandemic. METHODS: An Institutional Review Board-approved retrospective review of medical records identified patients who had an office-based oculofacial plastic surgery procedure during the pandemic between March and December 2020. Statistical analysis was used to compare this group to patients that underwent procedures between March and December 2019, prior to the pandemic when neither surgeon nor patient wore a surgical mask. RESULTS: The study consisted of 680 patients. Thirty-one different types of procedures were encountered. The incidence of infections in 2020 compared to 2019 was not statistically significant (1.12% (n = 3) versus 1.21% (n = 5), p = 1). All patients with infections were treated with oral antibiotics and improved without long-term complications. CONCLUSIONS: Periocular surgical site infections are uncommon, and the wearing of surgical masks by patient and surgeon during our office-based oculofacial procedures did not change the incidence of SSIs.
Ehlers JP, Yeh S, Maguire MG, Smith JR, Mruthyunjaya P, Jain N, Kim LA, Weng CY, Flaxel CJ, Schoenberger SD, Kim SJ. Intravitreal Pharmacotherapies for Diabetic Macular Edema: A Report by the American Academy of Ophthalmology. Ophthalmology 2021;Abstract
PURPOSE: To review the evidence on the safety and efficacy of current anti-vascular endothelial growth factor (VEGF) and intravitreal corticosteroid pharmacotherapies for the treatment of diabetic macular edema (DME). METHODS: Literature searches were last conducted on May 13, 2020, in the PubMed database with no date restrictions and limited to articles published in English. The combined searches yielded 230 citations, of which 108 were reviewed in full text. Of these, 31 were deemed appropriate for inclusion in this assessment and were assigned a level of evidence rating by the panel methodologist. RESULTS: Only the 21 articles with level I evidence were included in this assessment. Seventeen articles provided level I evidence for 1 or more anti-VEGF pharmacotherapies, including ranibizumab (14), aflibercept (5), and bevacizumab (2) alone or in combination with other treatments for DME. Level I evidence was identified in 7 articles on intravitreal corticosteroid therapy for treatment of DME: triamcinolone (1), dexamethasone (4), and fluocinolone acetonide (2). CONCLUSIONS: Review of the available literature indicates that intravitreal injections of anti-VEGF agents and corticosteroids are efficacious treatments for DME. Elevated intraocular pressure and cataract progression are important potential complications of corticosteroid therapy. Further evidence is required to assess the comparative efficacy of these therapies. Given the limited high-quality comparative efficacy data, choice of therapy must be individualized for each patient and broad therapeutic access for patients is critical to maximize outcomes.
Moon JY, Garg I, Cui Y, Katz R, Zhu Y, Le R, Lu Y, Lu ES, Ludwig CA, Elze T, Wu DM, Eliott D, Miller JW, Kim LA, Husain D, Vavvas DG, Miller JB. Wide-field swept-source optical coherence tomography angiography in the assessment of retinal microvasculature and choroidal thickness in patients with myopia. Br J Ophthalmol 2021;Abstract
BACKGROUND/AIMS: Pathological myopia (PM) is a leading cause of blindness worldwide. We aimed to evaluate microvascular and chorioretinal changes in different stages of myopia with wide-field (WF) swept-source (SS) optical coherence tomography angiography (OCTA). METHODS: This prospective cross-sectional observational study included 186 eyes of 122 patients who had undergone imaging between November 2018 and October 2020. Vessel density (VD) and vessel skeletonised density (VSD) of superficial capillary plexus, deep capillary plexus and whole retina, as well as foveal avascular zone parameters, retinal thickness (RT) and choroidal thickness (CT), were calculated. RESULTS: This study evaluated 75 eyes of 48 patients with high myopia (HM), 43 eyes of 31 patients with mild to moderate myopia and 68 eyes of 53 age-matched controls. Controlling for age and the presence of systemic hypertension, we found that HM was associated with decrease in VD and VSD in all layers on 12×12 mm² scans. Furthermore, HM was associated with a VD and VSD decrease in every Early Treatment Diabetic Retinopathy Study grid, with a larger decrease temporally (βVD=-0.39, βVSD=-10.25, p<0.01). HM was associated with decreased RT and CT. Reduction in RT was outside the macular region, while reduction in CT was in the macular region. CONCLUSION: Using WF SS-OCTA, we identified reduction in microvasculature and structural changes associated with myopia. Decrease in VD and VSD was greater in the temporal quadrant, and reductions in RT and CT were uneven across the retina. Further work may help identify risk factors for the progression of PM and associated vision-threatening complications.
Gowrisankaran S, Shah AS, Roberts TL, Wiecek E, Chinn RN, Hawash KK, O'Brien MJ, Howell DR, Meehan WP, Raghuram A. Association between post-concussion symptoms and oculomotor deficits among adolescents. Brain Inj 2021;:1-11.Abstract
PURPOSE: To examine the association between Post-Concussion Symptom Scale (PCSS) scores, Convergence Insufficiency Symptom Survey (CISS) scores, and oculomotor deficits post-concussion. METHODS: Records of adolescent patients examined in a multidisciplinary concussion clinic between July 2014 and May 2019 were reviewed. PCSS and CISS scores, results of eye examination and oculomotor assessment, concussion history, and demographics were abstracted. RESULTS: One hundred and forty patient records (median age, 15.3 years; 52 males, presented 109 days (median) from their most recent concussion) met inclusion criteria. Mean total scores on PCSS and CISS were 46.67 ± 25.89 and 27.13 ± 13.22, respectively, and were moderately correlated with each other (r = 0.53, p < .001). Oculomotor deficits were observed in 123 (88%) patients. Step-wise linear regression identified increased PCSS total score to be significantly associated with decreased amplitude of accommodation (p < .001). Increased CISS total score was significantly associated with receded near point of convergence, developmental eye movement test error scores, and cause of concussion. CONCLUSION: High PCSS scores may indicate an accommodation deficit and thus prompt an oculomotor assessment in patients following a concussion. Using the CISS and a detailed oculomotor assessment may reveal underlying oculomotor deficits, which may benefit from treatment.
Doshi H, Solli E, Elze T, Pasquale LR, Wall M, Kupersmith MJ. Unsupervised Machine Learning Identifies Quantifiable Patterns of Visual Field Loss in Idiopathic Intracranial Hypertension. Transl Vis Sci Technol 2021;10(9):37.Abstract
Purpose: Archetypal analysis, a form of unsupervised machine learning, identifies archetypal patterns within a visual field (VF) dataset such that any VF is described as a weighted sum of its archetypes (ATs) and has been used to quantify VF defects in glaucoma. We applied archetypal analysis to VFs affected by nonglaucomatous optic neuropathy caused by idiopathic intracranial hypertension (IIH). Methods: We created an AT model from 2862 VFs prospectively collected from 330 eyes in the IIH Treatment Trial (IIHTT). We compared baseline IIH AT patterns with their descriptive VF classifications from the IIHTT. Results: The optimum IIH AT model yielded 14 ATs resembling VF patterns reported in the IIHTT. Baseline VFs contained four or fewer meaningful ATs in 147 (89%) of study eyes. AT2 (mild general VF depression pattern) demonstrated the greatest number of study eyes with meaningful AT weight at baseline (n = 114), followed by AT1 (n = 91). Other ATs captured patterns of blind spot enlargement, hemianopia, arcuate, nasal defects, and more nonspecific patterns of general VF depression. Of all ATs, AT1 (normal pattern) had the strongest correlation with mean deviation (r = 0.69, P < 0.001). For 65 of the 93 VFs with a dominant AT, this AT matched the expert classification. Conclusions: Archetypal analysis identifies quantifiable, archetypal VF defects that resemble those commonly seen in IIH. Translational Relevance: Archetypal analysis provides a quantitative, objective method of measuring and monitoring disease-specific regional VF defects in IIH.
Wai KM, Locascio JJ, Wolkow N. Bacterial dacryoadenitis: clinical features, microbiology, and management of 45 cases, with a recent uptick in incidence. Orbit 2021;:1-9.Abstract
PURPOSE: To review the clinical features, microbiology, management, and incidence of bacterial dacryoadenitis at our institution. METHODS: This was a case series examining patients with bacterial dacryoadenitis from 2004 to 2020. Charts were reviewed for demographics, comorbidities, presenting symptoms and signs, radiology, microbiology, and management. Main outcomes included need for surgical intervention or inpatient admission. RESULTS: Forty-five patients with bacterial dacryoadenitis had a mean age of 46.1 years. Presenting symptoms included eyelid edema (100%), extraocular motility restriction (53.3%), and purulent discharge (75.5%). Based on computed tomography or magnetic resonance imaging, 9 (20.5%) patients presented with definite abscess and 15 (34%) presented with a phlegmon or early abscess. Eleven patients (24.4%) required surgical drainage. Twenty patients (44.4%) required admission, for an average stay of 4 days (range 2-8 days). Common organisms included Haemophilus influenzae, Streptococcus pneumoniae, and Staphylococcus aureus. Presence of an early abscess or phlegmon correlated with need for drainage (p < 0.01). Extraocular motility restriction correlated with need for drainage (p = 0.02) and admission (p = 0.05). The incidence of bacterial dacryoadenitis at our institution increased as a percentage of confirmed dacryoadenitis cases; from 2004 to 2010 the incidence was 0 to 9.1% per year, while from 2010 to 2019 the incidence ranged from 7.7 to 36.2%. In 2019, our institution had 17 cases (incidence 36.2%) of bacterial dacryoadenitis. CONCLUSIONS: Bacterial dacryoadenitis is a major cause of dacryoadenitis, and its incidence may be increasing. It can resolve with minimal complications if managed appropriately, although some patients may require surgical drainage or admission for intravenous antibiotics.