July 2021

Kaiser T, Allen HM, Kwon O, Barak B, Wang J, He Z, Jiang M, Feng G. MyelTracer: A Semi-Automated Software for Myelin -Ratio Quantification. eNeuro 2021;8(4)Abstract
In the central and peripheral nervous systems, the myelin sheath promotes neuronal signal transduction. The thickness of the myelin sheath changes during development and in disease conditions like multiple sclerosis. Such changes are routinely detected using electron microscopy through g-ratio quantification. While g-ratio is one of the most critical measurements in myelin studies, a major drawback is that g-ratio quantification is extremely laborious and time-consuming. Here, we report the development and validation of MyelTracer, an installable, stand-alone software for semi-automated g-ratio quantification based on the Open Computer Vision Library (OpenCV). Compared with manual g-ratio quantification, using MyelTracer produces consistent results across multiple tissues and animal ages, as well as in remyelination after optic nerve crush, and reduces total quantification time by 40-60%. With g-ratio measurements via MyelTracer, a known hypomyelination phenotype can be detected in a Williams syndrome mouse model. MyelTracer is easy to use and freely available for Windows and Mac OS X (https://github.com/HarrisonAllen/MyelTracer).
Kaseke C, Park RJ, Singh NK, Koundakjian D, Bashirova A, Garcia Beltran WF, Takou Mbah OC, Ma J, Senjobe F, Urbach JM, Nathan A, Rossin EJ, Tano-Menka R, Khatri A, Piechocka-Trocha A, Waring MT, Birnbaum ME, Baker BM, Carrington M, Walker BD, Gaiha GD. HLA class-I-peptide stability mediates CD8+ T cell immunodominance hierarchies and facilitates HLA-associated immune control of HIV. Cell Rep 2021;36(2):109378.Abstract
Defining factors that govern CD8+ T cell immunodominance is critical for the rational design of vaccines for viral pathogens. Here, we assess the contribution of human leukocyte antigen (HLA) class-I-peptide stability for 186 optimal HIV epitopes across 18 HLA alleles using transporter associated with antigen processing (TAP)-deficient mono-allelic HLA-expressing cell lines. We find that immunodominant HIV epitopes increase surface stabilization of HLA class-I molecules in comparison to subdominant epitopes. HLA class-I-peptide stability is also strongly correlated with overall immunodominance hierarchies, particularly for epitopes from high-abundance proteins (e.g., Gag). Moreover, HLA alleles associated with HIV protection are preferentially stabilized by epitopes derived from topologically important viral regions at a greater frequency than neutral and risk alleles. These findings indicate that relative stabilization of HLA class-I is a key factor for CD8+ T cell epitope immunodominance hierarchies, with implications for HIV control and the design of T-cell-based vaccines.
Kyari F, Bourne RRA, Khaw PT, Friedman DS, Congdon N, Ramke J, Burton MJ. Visual function rather than visual acuity - Authors' reply. Lancet Glob Health 2021;9(7):e914.
Lee SJ, Kim S-T, Wu J, Cho CS, Jo DH, Chen Y, Dana R, Kim JH, Lee S-M. Corneal lymphangiogenesis in dry eye disease is regulated by substance P/neurokinin-1 receptor system through controlling expression of vascular endothelial growth factor receptor 3. Ocul Surf 2021;22:72-79.Abstract
PURPOSE: To evaluate the role of substance P (SP)/neurokinin-1 receptor (NK1R) system in the regulation of pathologic corneal lymphangiogenesis in dry eye disease (DED). METHODS: Immunocytochemistry, angiogenesis assay, and Western blot analysis of human dermal lymphatic endothelial cells (HDLECs) were conducted to assess the involvement of SP/NK1R system in lymphangiogenesis. DED was induced in wild-type C57BL/6 J mice using controlled-environment chamber without scopolamine. Immunohistochemistry, corneal fluorescein staining, and phenol red thread test were used to evaluate the effect of SP signaling blockade in the corneal lymphangiogenesis. The expression of lymphangiogenic factors in the corneal and conjunctival tissues of DED mouse model was quantified by real-time polymerase chain reaction. RESULTS: NK1R expression and pro-lymphangiogenic property of SP/NK1R system in HDLECs were confirmed by Western blot analysis and angiogenesis assay. Blockade of SP signaling with L733,060, an antagonist of NK1R, or NK1R-targeted siRNA significantly inhibited lymphangiogenesis and expression of vascular endothelial growth factor (VEGF) receptor 3 stimulated by SP in HDLECs. NK1R antagonist also suppressed pathological corneal lymphangiogenesis and ameliorated the clinical signs of dry eye in vivo. Furthermore, NK1R antagonist effectively suppressed the lymphangiogenic factors, including VEGF-C, VEGF-D, and VEGF receptor 3 in the corneal and conjunctival tissues of DED. CONCLUSIONS: SP/NK1R system promotes lymphangiogenesis in vitro and NK1R antagonism suppresses pathologic corneal lymphangiogenesis in DED in vivo.
Ma KK, Yuan A, Sharifi S, Pineda R. A Biomechanical Study of Flanged Intrascleral Haptic Fixation of Three-Piece Intraocular Lenses. Am J Ophthalmol 2021;227:45-52.Abstract
PURPOSE: Flanged intrascleral haptic fixation (FISHF) is a useful method for securing intraocular lenses (IOLs) in eyes without capsular support. Biomechanical studies were conducted to support the use of this technique. DESIGN: Laboratory investigation. METHODS: Haptics of 3-piece IOLs were passed through cadaveric human sclera using 30- and 27-gauge needles. Flanges were created by melting 1.0 mm from the haptic ends using cautery. The forces required to remove the flanged haptic from the sclera and disinsert the haptic from the optic were measured using a mechanical tester and a custom-fabricated mount. RESULTS: The mean FISHF dislocation force using 30-gauge needles was greatest with the CT Lucia 602 (2.04 ± 0.24 newtons [N]) compared to the LI61AO (0.93 ± 0.41 N; P = .001), ZA9003 (0.70 ± 0.34 N; P = <.001), and MA60AC (0.27 ± 0.19 N; P <.001). Using 27-gauge needles with the CT Lucia resulted in a lower dislocation force (0.56 ± 0.36 N; P <.001). The FISHF dislocation force was correlated with the flange-to-needle diameter ratio (r = 0.975). The FISHF dislocation forces of the CT Lucia and LI61AO using 30-gauge needles were not significantly different from their haptic-optic disinsertion forces (P = .79 and .27, respectively). There were no differences in flange diameters between 1.0 mm and 2.0 mm haptic melt lengths across the IOLs (P = .15-.85). CONCLUSIONS: These data strongly support the biomechanical stability of FISHF with the polyvinylidene fluoride haptics of the CT Lucia using small diameter instruments for the creation of an intrascleral tunnel. 1.0 mm of haptic may be the optimal melt length.
Maleki A, Look-Why S, Asgari S, Manhapra A, Gomez S, Foster SC. Acquired Vitelliform-Like Lesion in Uveitis: A case-series. Ocul Immunol Inflamm 2021;:1-10.Abstract
PURPOSE: To study acquired vitelliform-like lesions (AVLL) and their diagnostic and prognostic values in uveitis. PATIENTS AND METHODS: This was a retrospective case series. The clinical course, diagnostic value, and prognostic significance of AVLL were compared between uveitic patients with AVLL and uveitic patients without AVLL. RESULTS: Twelve patients (21 eyes) with both uveitis and AVLL (study group) and thirteen patients (24 eyes) without AVLL (control group) were included in the study. Macular leakage (p = .005), the presence of vasculitis (p = .01), the presence of active choroiditis (p = .01), and the presence of CME on OCT (p = .008) were significantly higher in the AVLL group compared to the control group. Best-corrected visual acuity was significantly lower at presentation (p < .001) and the last follow-up visit (p = .014) in the AVLL group. CONCLUSION: The presence of acquired vitelliform-like lesion can have both a diagnostic (uveitis as a differential diagnosis) and prognostic value in patients with different types of uveitis.
Martinez-Carrasco R, Argüeso P, Fini EM. Membrane-associated mucins of the human ocular surface in health and disease. Ocul Surf 2021;21:313-330.Abstract
Mucins are a family of high molecular weight, heavily-glycosylated proteins produced by wet epithelial tissues, including the ocular surface epithelia. Densely-packed O-linked glycan chains added post-translationally confer the biophysical properties of hydration, lubrication, anti-adhesion and repulsion. Membrane-associated mucins (MAMs) are the distinguishing components of the mucosal glycocalyx. At the ocular surface, MAMs maintain wetness, lubricate the blink, stabilize the tear film, and create a physical barrier to the outside world. In addition, it is increasingly appreciated that MAMs function as cell surface receptors that transduce information from the outside to the inside of the cell. Recently, our team published a comprehensive review/perspectives article for molecular scientists on ocular surface MAMs, including previously unpublished data and analyses on two new genes MUC21 and MUC22, as well as new MAM functions and biological roles, comparing human and mouse (PMID: 31493487). The current article is a refocus for the audience of The Ocular Surface. First, we update the gene and protein information in a more concise form, and include a new section on glycosylation. Next, we discuss biological roles, with some new sections and further updating from our previous review. Finally, we provide a new chapter on MAM involvement in ocular surface disease. We end this with discussion of an emerging mechanism responsible for damage to the epithelia and their mucosal glycocalyces: the unfolded protein response (UPR). The UPR offers a novel target for therapeutic intervention.
Maturi RK, Glassman AR, Josic K, Antoszyk AN, Blodi BA, Jampol LM, Marcus DM, Martin DF, Melia M, Salehi-Had H, Stockdale CR, Punjabi OS, Sun JK, Sun JK. Effect of Intravitreous Anti-Vascular Endothelial Growth Factor vs Sham Treatment for Prevention of Vision-Threatening Complications of Diabetic Retinopathy: The Protocol W Randomized Clinical Trial. JAMA Ophthalmol 2021;139(7):701-712.Abstract
Importance: The role of anti-vascular endothelial growth factor injections for the management of nonproliferative diabetic retinopathy (NPDR) without center-involved diabetic macular edema (CI-DME) has not been clearly established. Objective: To determine the efficacy of intravitreous aflibercept injections compared with sham treatment in preventing potentially vision-threatening complications in eyes with moderate to severe NPDR. Design, Setting, and Participants: Data for this study were collected between January 15, 2016, and May 28, 2020, from the ongoing DRCR Retina Network Protocol W randomized clinical trial, conducted at 64 US and Canadian sites among 328 adults (399 eyes) with moderate to severe NPDR (Early Treatment Diabetic Retinopathy Study severity level, 43-53), without CI-DME. Analyses followed the intent-to-treat principle. Interventions: Eyes were randomly assigned to 2.0 mg of aflibercept injections (n = 200) or sham (n = 199) given at baseline; 1, 2, and 4 months; and every 4 months through 2 years. Between 2 and 4 years, treatment was deferred if the eye had mild NPDR or better. Aflibercept was administered in both groups if CI-DME with vision loss (≥10 letters at 1 visit or 5-9 letters at 2 consecutive visits) or high-risk proliferative diabetic retinopathy (PDR) developed. Main Outcomes and Measures: Development of CI-DME with vision loss or PDR through May 2020, when the last 2-year visit was completed. Results: Among the 328 participants (57.6% men [230 of 399 eyes]; mean [SD] age, 56 [11] years), the 2-year cumulative probability of developing CI-DME with vision loss or PDR was 16.3% with aflibercept vs 43.5% with sham. The overall hazard ratio for either outcome was 0.32 (97.5% CI, 0.21-0.50; P < .001), favoring aflibercept. The 2-year cumulative probability of developing PDR was 13.5% in the aflibercept group vs 33.2% in the sham group, and the 2-year cumulative probability of developing CI-DME with vision loss was 4.1% in the aflibercept group vs 14.8% in the sham group. The mean (SD) change in visual acuity from baseline to 2 years was -0.9 (5.8) letters with aflibercept and -2.0 (6.1) letters with sham (adjusted mean difference, 0.5 letters [97.5% CI, -1.0 to 1.9 letters]; P = .47). Conclusions and Relevance: In this randomized clinical trial, among eyes with moderate to severe NPDR, the proportion of eyes that developed PDR or vision-reducing CI-DME was lower with periodic aflibercept compared with sham treatment. However, through 2 years, preventive treatment did not confer visual acuity benefit compared with observation plus treatment with aflibercept only after development of PDR or vision-reducing CI-DME. The 4-year results will be important to assess longer-term visual acuity outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02634333.
McCoskey M, Neerukonda VK, Hatton MP, Wolkow N. Eccrine poroma of the eyelid. Orbit 2021;:1.Abstract
Clinical and histopathologic case of an eyelid eccrine poroma, a benign adnexal neoplasm rarely found on the periorbital skin.
McKay MK, Apostolopoulos N, Dahrouj M, Nguyen HV, Reddy A, Blazes M, Lacy M, Pepple KL, Lee AY, Lee CS. Assessing the Uniformity of Uveitis Clinical Concepts and Associated ICD-10 Codes Across Health Care Systems Sharing the Same Electronic Health Records System. JAMA Ophthalmol 2021;Abstract
Importance: Big data studies may allow for the aggregation of patients with rare diseases such as uveitis to answer important clinical questions. Standardization of uveitis-related variables will be necessary, including the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes used to identify patients of interest. There are currently limited data on the uniformity of diagnosis mapping to ICD-10 codes for uveitis diagnoses among different health systems. Objective: To assess the degree of uniformity in mapping of uveitis clinical concepts to ICD-10 codes across health care systems using the same electronic health record (EHR) system. Design, Setting, and Participants: This multicenter survey study was conducted between September 14 and October 9, 2020, at 5 academic health care systems that use the Epic EHR. Researchers from the University of Washington, Harvard University, Stanford University, Yale University, and the University of California, San Francisco queried 54 uveitis-related diagnostic terms and recorded the associated ICD-10 codes. Main Outcomes and Measures: The degree of uniformity for uveitis clinical concepts and associated ICD-10 codes. Results: Fifty-four uveitis-related diagnostic terms were queried within the Epic EHR at 5 different health care systems. There was perfect agreement among all 5 centers for 52 of the 54 diagnostic terms. Two diagnostic terms had differences in ICD-10 coding: juvenile idiopathic arthritis associated chronic uveitis and intermediate uveitis. Intermediate uveitis was associated with codes H20.1x (ICD-10 description: chronic iridocyclitis) or H20.9 (ICD-10 description: unspecified iridocyclitis) in 3 centers while being associated with code H30.2x (ICD-10 description: posterior cyclitis) at the 2 remaining centers. The discrepancies appear to be related to a recent update in diagnostic mapping in the Epic EHR. Conclusions and Relevance: This study suggests that ICD-10 code mapping to uveitis diagnostic terminology appears to be highly uniform at different centers with the Epic EHR. However, temporal changes in diagnosis mapping to ICD-10 codes and a lack of 1-to-1 mapping of diagnosis to ICD-10 code add additional sources of complexity to the interpretation of big data studies in uveitis.
Monés J, Srivastava SK, Jaffe GJ, Tadayoni R, Albini TA, Kaiser PK, Holz FG, Korobelnik J-F, Kim IK, Pruente C, Murray TG, Heier JS. Risk of Inflammation, Retinal Vasculitis, and Retinal Occlusion-Related Events with Brolucizumab: Post Hoc Review of HAWK and HARRIER. Ophthalmology 2021;128(7):1050-1059.Abstract
PURPOSE: An independent Safety Review Committee (SRC), supported by Novartis Pharma AG, analyzed investigator-reported cases of intraocular inflammation (IOI), endophthalmitis, and retinal arterial occlusion in the phase 3 HAWK and HARRIER trials of brolucizumab versus aflibercept in neovascular age-related macular degeneration (nAMD). DESIGN: A post hoc analysis of a subset of data from two 2-year, double-masked, multicenter, active-controlled randomized phase 3 trials (NCT02307682, NCT02434328). PARTICIPANTS: Patients (N = 1817) with untreated, active choroidal neovascularization due to age-related macular degeneration in the study eye were randomized and treated in HAWK/HARRIER. The SRC reviewed data from cases of investigator-reported IOI (60/1088 brolucizumab-treated eyes; 8/729 aflibercept-treated eyes). METHODS: The SRC received details and images (color fundus photography, fluorescein angiography, and OCT) for all investigator-determined cases of IOI, retinal arterial occlusion, and endophthalmitis. Cases were reviewed in detail by ≥2 readers, then adjudicated by the SRC as a group. MAIN OUTCOME MEASURES: Within this patient subset: incidence of IOI, signs and incidence of retinal vasculitis and/or retinal vascular occlusion, and visual acuity loss; time since first brolucizumab injection to IOI event onset; and frequency of visual acuity loss after brolucizumab injection by time of first IOI event onset. RESULTS: Fifty brolucizumab-treated eyes were considered to have definite/probable drug-related events within the spectrum of IOI, retinal vasculitis, and/or vascular occlusion. On the basis of these cases, incidence of definite/probable IOI was 4.6% (IOI + vasculitis, 3.3%; IOI + vasculitis + occlusion, 2.1%). There were 8 cases (incidence 0.74%) of at least moderate visual acuity loss (≥15 ETDRS letters) in eyes with IOI (7 in eyes with IOI + vasculitis + occlusion). Of the 8 cases, 5 experienced their first IOI-related event within 3 months of the first brolucizumab injection (increasing to 7/8 within 6 months). Incidence of IOI in aflibercept-treated eyes was 1.1%, with at least moderate visual acuity loss in 0.14%. CONCLUSIONS: This analysis of IOI cases after brolucizumab injection identified signs of retinal vasculitis with or without retinal vascular occlusion and an associated risk of visual acuity loss. The findings will help physicians to evaluate the risks and benefits of brolucizumab treatment for nAMD.
Mychaleckyj J, Valo E, Ichimura T, Ahluwalia T, Dina C, Miller R, Shabalin I, Gyorgy B, Cao J, Onengut-Gumuscu S, Satake E, Smiles A, Haukka J, Tregouet D-A, Costacou T, O'Neil K, Paterson A, Forsblom C, Keenan H, Pezzolesi M, Pragnell M, Galecki A, Rich S, Sandholm N, Klein R, Klein B, Susztak K, Orchard T, Korstanje R, King G, Hadjadj S, Rossing P, Bonventre J, Groop P-H, Warram J, Krolewski A. Association of Coding Variants in Hydroxysteroid 17-beta Dehydrogenase 14 (HSD17B14) with Reduced Progression to End Stage Kidney Disease in Type 1 Diabetes. J Am Soc Nephrol 2021;Abstract
BACKGROUND: Rare variants in gene coding regions likely have a greater impact on disease-related phenotypes than common variants through disruption of their encoded protein. We searched for rare variants associated with onset of end stage kidney disease (ESKD) in individuals with type 1 diabetes at advanced kidney disease stage. METHODS: Gene-based exome array analysis of 15,449 genes in 5 large incidence cohorts of individuals with type 1 diabetes and proteinuria were analyzed for survival time-to-ESKD, testing the top gene in a 6th cohort (N=2,372/1,115 events all cohorts) and replicating in two retrospective case-control studies (N=1,072 cases, 752 controls). Deep resequencing of the top associated gene in 5 cohorts confirmed the findings. We performed immunohistochemistry and gene expression experiments in human control and diseased cells, and in mouse ischemia reperfusion and aristolochic acid nephropathy models. RESULTS: Protein coding variants in the hydroxysteroid 17-beta dehydrogenase 14 gene (HSD17B14), predicted to affect protein structure, had a net protective effect against development of ESKD at exome-wide significance (N=4,196; p-value=3.3x10-7). The HSD17B14 gene and encoded enzyme were robustly expressed in healthy human kidney, maximally in proximal tubular cells. Paradoxically, gene and protein expression were attenuated in human diabetic proximal tubules and in mouse kidney injury models. Expressed HSD17B14 gene and protein levels remained low without recovery after 21 days in a murine ischemic reperfusion injury model. Decreased gene expression was found in other chronic kidney disease-associated renal pathologies. CONCLUSIONS: HSD17B14 gene is mechanistically involved in diabetic kidney disease. The encoded sex steroid enzyme is a druggable target, potentially opening a new avenue for therapeutic development.
Neerukonda VK, Stagner AM, Wolkow N. Florid sympathetic ophthalmia. Orbit 2021;:1.
Nilsson AK, Andersson MX, Sjöbom U, Hellgren G, Lundgren P, Pivodic A, Smith LEH, Hellström A. Sphingolipidomics of serum in extremely preterm infants: Association between low sphingosine-1-phosphate levels and severe retinopathy of prematurity. Biochim Biophys Acta Mol Cell Biol Lipids 2021;1866(7):158939.Abstract
BACKGROUND: Extremely preterm infants are at risk of developing retinopathy of prematurity (ROP) that can cause impaired vision or blindness. Changes in blood lipids have been associated with ROP. This study aimed to monitor longitudinal changes in the serum sphingolipidome of extremely preterm infants and investigate the relationship to development of severe ROP. METHODS: This is a prospective study that included 47 infants born <28 gestational weeks. Serum samples were collected from cord blood and at postnatal days 1, 7, 14, and 28, and at postmenstrual weeks (PMW) 32, 36, and 40. Serum sphingolipids and phosphatidylcholines were extracted and analyzed by LC-MS/MS. Associations between sphingolipid species and ROP were assessed using mixed models for repeated measures. RESULTS: The serum concentration of all investigated lipid classes, including ceramide, mono- di- and trihexosylceramide, sphingomyelin, and phosphatidylcholine displayed distinct temporal patterns between birth and PMW40. There were also substantial changes in the lipid species composition within each class. Among the analyzed sphingolipid species, sphingosine-1-phosphate showed the strongest association with severe ROP, and this association was independent of gestational age at birth and weight standard deviation score change. CONCLUSIONS: The serum phospho- and sphingolipidome undergoes significant remodeling during the first weeks of the preterm infant's life. Low postnatal levels of the signaling lipid sphingosine-1-phosphate are associated with the development of severe ROP.
O'Hare M, Amarnani D, Whitmore HAB, An M, Marino C, Ramos L, Delgado-Tirado S, Hu X, Chmielewska N, Chandrahas A, Fitzek A, Heinrich F, Steurer S, Ondruschka B, Glatzel M, Krasemann S, Sepulveda-Falla D, Lagares D, Pedron J, Bushweller JH, Liu P, Arboleda-Velasquez JF, Kim LA. Targeting Runt-Related Transcription Factor 1 Prevents Pulmonary Fibrosis and Reduces Expression of Severe Acute Respiratory Syndrome Coronavirus 2 Host Mediators. Am J Pathol 2021;191(7):1193-1208.Abstract
Pulmonary fibrosis (PF) can arise from unknown causes, as in idiopathic PF, or as a consequence of infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current treatments for PF slow, but do not stop, disease progression. We report that treatment with a runt-related transcription factor 1 (RUNX1) inhibitor (Ro24-7429), previously found to be safe, although ineffective, as a Tat inhibitor in patients with HIV, robustly ameliorates lung fibrosis and inflammation in the bleomycin-induced PF mouse model. RUNX1 inhibition blunted fundamental mechanisms downstream pathologic mediators of fibrosis and inflammation, including transforming growth factor-β1 and tumor necrosis factor-α, in cultured lung epithelial cells, fibroblasts, and vascular endothelial cells, indicating pleiotropic effects. RUNX1 inhibition also reduced the expression of angiotensin-converting enzyme 2 and FES Upstream Region (FURIN), host proteins critical for SARS-CoV-2 infection, in mice and in vitro. A subset of human lungs with SARS-CoV-2 infection overexpress RUNX1. These data suggest that RUNX1 inhibition via repurposing of Ro24-7429 may be beneficial for PF and to battle SARS-CoV-2, by reducing expression of viral mediators and by preventing respiratory complications.
Ou J, Zhou Z, Dai R, Zhang J, Zhao S, Wu X, Lan W, Ren Y, Cui L, Lan Q, Lu L, Seto D, Chodosh J, Wu J, Zhang G, Zhang Q. V367F Mutation in SARS-CoV-2 Spike RBD Emerging during the Early Transmission Phase Enhances Viral Infectivity through Increased Human ACE2 Receptor Binding Affinity. J Virol 2021;95(16):e0061721.Abstract
The current pandemic of COVID-19 is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 spike protein receptor-binding domain (RBD) is the critical determinant of viral tropism and infectivity. To investigate whether naturally occurring RBD mutations during the early transmission phase have altered the receptor binding affinity and infectivity, we first analyzed in silico the binding dynamics between SARS-CoV-2 RBD mutants and the human angiotensin-converting enzyme 2 (ACE2) receptor. Among 32,123 genomes of SARS-CoV-2 isolates (December 2019 through March 2020), 302 nonsynonymous RBD mutants were identified and clustered into 96 mutant types. The six dominant mutations were analyzed applying molecular dynamics simulations (MDS). The mutant type V367F continuously circulating worldwide displayed higher binding affinity to human ACE2 due to the enhanced structural stabilization of the RBD beta-sheet scaffold. The MDS also indicated that it would be difficult for bat SARS-like CoV to infect humans. However, the pangolin CoV is potentially infectious to humans. The increased infectivity of V367 mutants was further validated by performing receptor-ligand binding enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance, and pseudotyped virus assays. Phylogenetic analysis of the genomes of V367F mutants showed that during the early transmission phase, most V367F mutants clustered more closely with the SARS-CoV-2 prototype strain than the dual-mutation variants (V367F+D614G), which may derivate from recombination. The analysis of critical RBD mutations provides further insights into the evolutionary trajectory of early SARS-CoV-2 variants of zoonotic origin under negative selection pressure and supports the continuing surveillance of spike mutations to aid in the development of new COVID-19 drugs and vaccines. IMPORTANCE A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused the pandemic of COVID-19. The origin of SARS-CoV-2 was associated with zoonotic infections. The spike protein receptor-binding domain (RBD) is identified as the critical determinant of viral tropism and infectivity. Thus, whether mutations in the RBD of the circulating SARS-CoV-2 isolates have altered the receptor binding affinity and made them more infectious has been the research hot spot. Given that SARS-CoV-2 is a novel coronavirus, the significance of our research is in identifying and validating the RBD mutant types emerging during the early transmission phase and increasing human angiotensin-converting enzyme 2 (ACE2) receptor binding affinity and infectivity. Our study provides insights into the evolutionary trajectory of early SARS-CoV-2 variants of zoonotic origin. The continuing surveillance of RBD mutations with increased human ACE2 affinity in human or other animals is critical to the development of new COVID-19 drugs and vaccines against these variants during the sustained COVID-19 pandemic.
Patel S, Yuan A, Pineda R. Acute Benign Paroxysmal Positional Vertigo After Endothelial Keratoplasty-A Unique Cause of Postoperative Nausea and Headache. Cornea 2021;40(7):926-929.Abstract
PURPOSE: To describe a case of new-onset benign paroxysmal positional vertigo (BPPV) after uncomplicated Descemet stripping automated endothelial keratoplasty. METHODS: Case report and review of literature. RESULTS: A 61-year-old woman with a history of steroid-induced glaucoma and penetrating keratoplasty for Fuchs endothelial dystrophy, and no history of BPPV or other vertigo, underwent Descemet stripping automated endothelial keratoplasty for penetrating keratoplasty graft failure. On the third postoperative day, she developed acute spinning vertigo, nausea, and headache on sitting up after 3 days of strict supine positioning. Her ophthalmic examination was benign, with no evidence of a pupillary block, and she was diagnosed by an otologist with BPPV. Her symptoms resolved after 1 week without further intervention. CONCLUSIONS: BPPV is a benign but rare complication of nonotologic surgery and has not been previously reported with ophthalmic surgery. The overlap in symptomatology between BPPV and other serious and potentially vision-threatening causes of postoperative nausea and headache, such as pupillary block glaucoma, makes this a relevant etiology to consider in the spectrum of postendothelial keratoplasty complications.
Qiu M, Woreta FA, Boland MV. Microinvasive Glaucoma Surgery in US Ophthalmology Residency: Surgical Case Log Cross-sectional Analysis and Proposal for New Glaucoma Procedure Classification. J Glaucoma 2021;30(7):621-628.Abstract
PRECIS: A cross-sectional sample of the US ophthalmology residency graduating class of 2018 revealed that 18.4% of residents logged <5 traditional glaucoma surgeries, and 63.4% logged at least 1 microinvasive glaucoma surgery (MIGS). PURPOSE: Describe the state of MIGS in US ophthalmology residency training and propose a glaucoma procedure classification system for residents' surgical case logs. METHODS: Deidentified case logs from residents graduating in 2018 were requested from US residency program directors. RESULTS: Case logs were received for 152/488 (31%) residents from 36/115 (31%) programs. The mean number of traditional glaucoma surgeries per resident was 9.0±5.9 (range: 0 to 31). The mean number of MIGS per resident was 5.2±8.9 cases (range: 0 to 58). There were 28/152 (18.4%) residents from 16/36 (44.4%) programs who logged <5 traditional glaucoma surgeries as primary surgeon, and 3/152 (2.0%) residents from 3/36 (8.3%) programs who logged zero traditional glaucoma surgeries as primary surgeon. There were 98/152 (64.5%) residents from 32/36 (88.8%) programs who logged <5 MIGS as primary surgeon, and 48/152 (31.6%) residents from 25 of 36 (69.4%) programs who logged zero MIGS as primary surgeon. There were 104/152 (63.4%) residents from 33/36 (91.6%) programs who logged at least 1 MIGS as primary surgeon; there were 3/36 (8.3%) residency programs where no resident logged any MIGS as primary surgeon. CONCLUSIONS: US ophthalmology residents' MIGS experience varies widely. Residents can satisfy glaucoma surgery requirements with some MIGS, even in the absence of adequate traditional glaucoma surgeries. We propose a residency case log classification system that better reflects the growing role of MIGS in clinical practice and helps ophthalmic educators more accurately track procedures requiring related skills.
Rashad R, Shanbhag SS, Kwan J, Chodosh J, Saeed S, Saeed HN. Chronic ocular complications in lamotrigine vs. trimethoprim-sulfamethoxazole induced Stevens-Johnson syndrome/toxic epidermal necrolysis. Ocul Surf 2021;21:16-18.Abstract
PURPOSE: The purpose of this study is to compare the severity of chronic ocular complications of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) induced by lamotrigine (LT) vs. trimethoprim-sulfamethoxazole (TS). METHODS: This retrospective cross-sectional study evaluated all SJS/TEN patients treated within our hospital network from 2008 to 2018. Inclusion criteria included patients with reactions identified as caused by either LT or TS, and patients with at least one ophthalmology follow up in the chronic phase (≥3 months from disease onset). Primary outcome measures included LogMAR best-corrected VA at most recent visit and the presence or absence of severe ocular complications (SOC). Secondary outcome measures included chronic ocular complication severity scores using a modified Sotozono scoring system. RESULTS: Forty-eight eyes of 24 patients were included in the study. The mean duration of follow-up was 39.50 ± 35.62 vs. 48.17 ± 33.09 months, respectively (p = 0.482). The LT group had worse average VA at the most recent visit (LogMAR VA; 0.508 vs. 0.041, p < 0.0001) and had a higher prevalence of SOCs (66.7% vs. 8.3%, p = 0.0038). The LT group scored worse on Sotozono chronic complications scores for the cornea (1.875 vs. 0.5, p = 0.0018), eyelid margin (5.583 vs.3.083, p = 0.0010), and overall condition (8.500 vs. 4.833, p = 0.0015). Sub-analyses showed that a moderate or severe acute ocular severity score was a significant predictor of chronic outcomes. CONCLUSIONS: Compared to patients with TS-induced SJS/TEN, patients with LT-induced SJS/TEN developed worse chronic ocular complications on several parameters. Future prospective studies are warranted to provide additional insight into the drug type as a predictor of chronic ocular complications.
Ruiz-Lozano RE, Garza-Garza LA, Davila-Cavazos O, Foster SC, Rodriguez-Garcia A. The clinical and pathogenic spectrum of surgically-induced scleral necrosis: A review. Surv Ophthalmol 2021;66(4):594-611.Abstract
The onset of scleral necrosis after ocular surgery may have catastrophic ocular and systemic consequences. The two most frequent surgeries causing surgically-induced scleral necrosis (SISN) are pterygium excision and cataract extraction. Several pathogenic mechanisms are involved in surgically induced scleral necrosis. All of them are poorly understood. Ocular trauma increasing lytic action of collagenases with subsequent collagen degradation, vascular disruption leading to local ischemia, and immune complex deposition activating the complement system represents some of the events that lead to scleral necrosis. The complex cascade of events involving different pathogenic mechanisms and the patient's abnormal immune response frequently leads to delayed wound healing that predisposes the development of scleral necrosis. The management of SISN ranges from short-term systemic anti-inflammatory drugs to aggressive immunosuppressive therapy and surgical repair. Therefore, before performing any ocular surgery involving the sclera, a thorough ophthalmic and systemic evaluation must be done to identify high-risk patients that may develop SISN.