Nonredundant Role of Leishmanolysin-Like (Lmln) Zinc-Metallopeptidase in Retinal Homeostasis.

Purpose: To determine if Lmln, a Zinc-metallopeptidase, is important for retinal homeostasis.

Design: Basic research in mouse models of retinal degeneration.

Methods: Combining an unbiased N-ethyl-N-nitrosourea mutagenesis pipeline in mice with optical coherence tomography (OCT) screening and automated meiotic mapping, we identified an allele (nemeth) that seemed to be associated with outer nuclear layer (ONL) thinning.

Atypical Central Serous Chorioretinopathy Masquerading as Vogt-Koyanagi-Harada Disease: A Case Report.

Introduction: We aimed to describe a clinical presentation of central serous retinopathy that poses a diagnostic and management dilemma.

Case Presentation: A 30-year-old male patient presented with bilateral vision loss and multifocal serous retinal detachments involving the posterior pole of both eyes. Optical coherence tomography revealed prominent bilateral bacillary layer detachments.

E3 ubiquitin ligase Herc3 deficiency leads to accumulation of subretinal microglia and retinal neurodegeneration.

Activated microglia have been implicated in the pathogenesis of age-related macular degeneration (AMD), diabetic retinopathy, and other neurodegenerative and neuroinflammatory disorders, but our understanding of the mechanisms behind their activation is in infant stages. With the goal of identifying novel genes associated with microglial activation in the retina, we applied a semiquantitative fundus spot scoring scale to an unbiased, state-of-the-science mouse forward genetics pipeline. A mutation in the gene encoding the E3 ubiquitin ligase Herc3 led to prominent accumulation of fundus spots.

Impact of COVID-19-related lifestyle changes on diabetic macular edema.

Aim: To assess diabetic macular edema (DME) progression during the early phases of the COVID-19 pandemic, when severe societal restrictions raised the concern of possible deterioration of health in patients with systemic conditions, particularly those requiring frequent office visits.

Methods: This is a multicenter retrospective chart review of 370 patients (724 eyes) with an established diagnosis of DME seen on 3 separate visits between January 2019 and July 2021. Period 1 was January 2019 to February 2020 (considered pre-COVID-19), period 2 was March 2020 to December 2020 (considered the height of the pandemic; highest level of pandemic-related clinical and societal regulations) and period 3 was January 2021 to July 2021 (re-adjustment to the new "pandemic norms").

Single Cell RNA Sequencing Analysis of Mouse Retina Identifies a Subpopulation of Muller Glia Involved in Retinal Recovery From Injury in the FCD-LIRD Model.

Purpose: Although retinal light injury models have been useful in understanding aspects of retinal degeneration and retinal oxidative stress, information on retinal recovery from oxidative/photoinflammatory retinal injury is scarce. The fundus camera-delivered light-induced retinal degeneration model is a simple and reproducible retinal light injury model developed to recapitulate not only the retinal degeneration aspect, but also the retinal recovery from injury. In this study, we used the fundus camera-delivered light-induced retinal degeneration model to perform cell type-specific analyses of the acute and subacute retinal responses to light injury.

Forward genetic screening using fundus spot scale identifies an essential role for Lipe in murine retinal homeostasis.

Microglia play a role in the pathogenesis of many retinal diseases. Fundus spots in mice often correlate with the accumulation of activated subretinal microglia. Here we use a semiquantitative fundus spot scoring scale in combination with an unbiased, state-of-the-science forward genetics pipeline to identify causative associations between chemically induced mutations and fundus spot phenotypes.

Comparison of Surgical Outcomes for Uncomplicated Primary Retinal Detachment Repair.

Purpose: To compare the outcomes of primary uncomplicated rhegmatogenous retinal detachment (RRD) repair using pars plana vitrectomy (PPV), scleral buckling (SB), or combined scleral buckling with vitrectomy (SB/PPV).

Patients And Methods: Single-institution, retrospective, observational study of 179 patients with primary RRD managed at a large academic hospital system. We excluded patients with less than 6 months of follow-up, previous vitrectomy or buckle, giant retinal tears, aphakia, recurrent forms of RRD, or extensive proliferative vitreoretinopathy (Grade C or worse) documented on exam or requiring membrane peel.

Parafoveal acute middle maculopathy (PAMM) in sickle cell disease after discontinuation of hydroxyurea.

Purpose: Paracentral acute middle maculopathy (PAMM) is a rare ophthalmologic emergency involving the intermediate and deep retinal capillary plexus that supply the retina's middle layers. This case report describes an episode of PAMM in a patient with sickle cell disease (SCD) to demonstrate the importance of early diagnosis, review potential pathophysiologic mechanisms, and finally discuss appropriate management in this patient population.

Observations: A 33-year-old black female with SCD, who had recently discontinued disease-modifying therapy with hydroxyurea, presented with a central scotoma of the left eye.

Utility of the DHFR-based destabilizing domain across mouse models of retinal degeneration and aging.

The dihydrofolate reductase (DHFR) destabilizing domain (DD) serves as a promising approach to conditionally regulate protein abundance in a variety of tissues. To test whether this approach could be effectively applied to a wide variety of aged and disease-related ocular mouse models, we evaluated the DHFR DD system in the eyes of aged mice (up to 24 months), a light-induced retinal degeneration (LIRD) model, and two genetic models of retinal degeneration ( and mice). The DHFR DD was effectively degraded in all model systems, including mice, which showed significant defects in chymotrypsin proteasomal activity.

Unexpected Etiology in a Case of Bilateral Maculopathy.

A 74-year-old woman with a history of rheumatoid arthritis using hydroxychloroquine presented with gradually progressive decreased vision in both eyes and was found to have a bilateral maculopathy. Initial genetic testing was negative, and after discussing the low likelihood of her severe findings being secondary to her relatively low hydroxychloroquine exposure, the possibility of an autoimmune retinopathy was entertained. Updated data on the genetic testing reclassified one of her mutations in HGSNAT as pathogenic.

Forward genetic analysis using OCT screening identifies mutations leading to progressive outer retinal degeneration in mice.

Retinal disease and loss of vision can result from any disruption of the complex pathways controlling retinal development and homeostasis. Forward genetics provides an excellent tool to find, in an unbiased manner, genes that are essential to these processes. Using -ethyl--nitrosourea mutagenesis in mice in combination with a screening protocol using optical coherence tomography (OCT) and automated meiotic mapping, we identified 11 mutations presumably causative of retinal phenotypes in genes previously known to be essential for retinal integrity.

Delivery of Antisense Oligonucleotides to the Cornea.

Antisense oligonucleotides (ASOs) are synthetic nucleic acids that recognize complementary RNA sequences inside cells and modulate gene expression. In this study, we explore the feasibility of ASO delivery to the cornea. We used quantitative polymerase chain reaction to test the efficacy of a benchmark ASO targeting a noncoding nuclear RNA, Metastasis-Associated Lung Adenocarcinoma Transcript 1 (), in a human corneal endothelial cell line, human corneas, and in mice.

Mice With a Combined Deficiency of Superoxide Dismutase 1 (Sod1), DJ-1 (Park7), and Parkin (Prkn) Develop Spontaneous Retinal Degeneration With Aging.

Purpose: Chronic oxidative stress is an important mechanism of disease in aging disorders. We do not have a good model to recapitulate AMD and other retinal disorders in which chronic oxidative stress plays an important role. We hypothesized that mice with a combined deficiency in superoxide dismutase 1 (Sod1), DJ-1 (Park-7), and Parkin (Prkn) (triple knock out, TKO) would have an increased level of chronic oxidative stress in the retina, with anatomic and functional consequences just with aging.

Vitreoretinal lymphoma, secondary to non-CNS systemic lymphoma, masquerading as an infectious retinitis.

Purpose: To report an atypical case of vitreoretinal lymphoma, secondary to non-central nervous system (non-CNS) systemic lymphoma, masquerading as an infectious retinitis.

Observations: A 76-year-old female with a history of cecal diffuse large B-cell lymphoma with two prior occurrences of posterior segment ocular involvement presented with a complaint of blurry vision in the right eye. Exam findings were significant for large areas of retinal whitening and retinal hemorrhages in the absence of choroidal lesions or significant vitritis.

A Mouse Model of Retinal Recovery From Photo-Oxidative/Photo-Inflammatory Injury: Nrf2, SOD1, DJ-1, and Parkin Are Not Essential to Recovery.

Purpose: To determine if there is structural and functional recovery of the retina from light induced retinal degeneration, and to evaluate the role of the oxidative stress response elements Nrf2, SOD1, DJ-1, and Parkin in such a recovery process.

Methods: Eyes from C57BL/6J (B6J) mice and from oxidative stress response-deficient strains of mice were treated with intense light using the fundus camera-delivered light-induced retinal degeneration (FCD-LIRD) model. Fundus photographs, optical coherence tomography (OCT) images, and electroretinography (ERG) responses were obtained before the injury, during the "maximal injury phase" (days 4-7) and during the "recovery phase" (days 14-16) post light exposure and were evaluated for retinal damage and assessed for evidence of recovery from the injury.

Increased susceptibility to fundus camera-delivered light-induced retinal degeneration in mice deficient in oxidative stress response proteins.

Oxidative stress is an important contributor to the pathogenesis of many retinal diseases including age-related macular degeneration and retinal dystrophies. Light-induced retinal degeneration (LIRD) can serve as a model in which to study the response of the retina to stress. Of note, many genetic mutant mice are in a C57BL/6 J background and are thus resistant to the usual LIRD models.

Fundus Camera-Delivered Light-Induced Retinal Degeneration in Mice With the RPE65 Leu450Met Variant is Associated With Oxidative Stress and Apoptosis.

Purpose: Oxidative stress, partly due to light, has an important role in many retinal diseases, including macular degeneration and retinal dystrophies. The Leu450Met variant of RPE65 is expressed in C57BL/6 and in many genetically modified mice. It confers significant resistance to light induced retinal degeneration (LIRD).

Phosphatidylserine (PS) Is Exposed in Choroidal Neovascular Endothelium: PS-Targeting Antibodies Inhibit Choroidal Angiogenesis In Vivo and Ex Vivo.

Purpose: Choroidal neovascularization (CNV) accounts for 90% of cases of severe vision loss in patients with advanced age-related macular degeneration. Identifying new therapeutic targets for CNV may lead to novel combination therapies to improve outcomes and reduce treatment burden. Our goal was to test whether phosphatidylserine (PS) becomes exposed in the outer membrane of choroidal neovascular endothelium, and whether this could provide a new therapeutic target for CNV.

A chimeric Cfh transgene leads to increased retinal oxidative stress, inflammation, and accumulation of activated subretinal microglia in mice.

Purpose: Variants of complement factor H (Cfh) affecting short consensus repeats (SCRs) 6 to 8 increase the risk of age-related macular degeneration. Our aim was to explore the effect of expressing a Cfh variant on the in vivo susceptibility of the retina and RPE to oxidative stress and inflammation, using chimeric Cfh transgenic mice (chCfhTg).

Methods: The chCfhTg and age-matched C57BL/6J (B6) mice were subjected to oxidative stress by either normal aging, or by exposure to a combination of oral hydroquinone (0.

Differences in the distribution, phenotype and gene expression of subretinal microglia/macrophages in C57BL/6N (Crb1 rd8/rd8) versus C57BL6/J (Crb1 wt/wt) mice.

Background: Microglia/macrophages (MG/MΦ) are found in the subretinal space in both mice and humans. Our goal was to study the spatial and temporal distribution, the phenotype, and gene expression of subretinal MG/MΦ in mice with normal retinas and compare them to mice with known retinal pathology.

Methods: We studied C57BL/6 mice with (C57BL/6N), or without (C57BL/6J) the rd8 mutation in the Crb1 gene (which, in the presence of yet unidentified permissive/modifying genes, leads to a retinal degeneration), and documented their fundus appearance and the change with aging.

Nonfunctional variant 3 factor H binding proteins as meningococcal vaccine candidates.

Neisseria meningitidis is a human-specific pathogen and leading cause of meningitis and septicemia. Factor H binding protein (fHbp), a virulence factor which protects N. meningitidis from innate immunity by binding the human complement regulator factor H (fH) with high affinity, is also a key antigen in vaccines being developed to prevent meningococcal disease.

Factor H binds to the hypervariable region of many Streptococcus pyogenes M proteins but does not promote phagocytosis resistance or acute virulence.

Many pathogens express a surface protein that binds the human complement regulator factor H (FH), as first described for Streptococcus pyogenes and the antiphagocytic M6 protein. It is commonly assumed that FH recruited to an M protein enhances virulence by protecting the bacteria against complement deposition and phagocytosis, but the role of FH-binding in S. pyogenes pathogenesis has remained unclear and controversial.

Design and evaluation of meningococcal vaccines through structure-based modification of host and pathogen molecules.

Neisseria meningitis remains a leading cause of sepsis and meningitis, and vaccines are required to prevent infections by this important human pathogen. Factor H binding protein (fHbp) is a key antigen that elicits protective immunity against the meningococcus and recruits the host complement regulator, fH. As the high affinity interaction between fHbp and fH could impair immune responses, we sought to identify non-functional fHbps that could act as effective immunogens.

Novel method for the rapid isolation of RPE cells specifically for RNA extraction and analysis.

RPE cells are involved in the pathogenesis of many retinal diseases. Accurate analysis of RPE gene expression profiles in different scenarios will increase our understanding of disease mechanisms. Our objective in this study was to develop an improved method for the isolation of RPE cells, specifically for RNA analysis.

Next-generation therapeutic solutions for age-related macular degeneration.

Age-related macular degeneration (AMD) is the primary cause of irreversible blindness among the elderly in the western world. To date, no cure is available and the current anti-VEGF therapy has only shown limited efficacy in improving visual acuity in neovascular AMD. The etiology of AMD remains elusive but research over the past decade has uncovered characteristic features of the disease.