Selumetinib in the Treatment of Orbital Plexiform Neurofibroma: A Case Report.

A 4-year-old boy with a known diagnosis of neurofibromatosis 1 (NF1) and a diffusely infiltrative plexiform neurofibroma (PN) of the left orbit was started on selumetinib treatment for progressively worsening amblyopia. The patient first presented with new-onset left ptosis at 11 months old. He subsequently developed refractory anisometropic amblyopia of the left eye, in addition to clinically significant left proptosis and hypoglobus that interfered with glasses wear for his amblyopia treatment. The plexiform neurofibroma was not amenable to surgical resection and selumetinib treatment was initiated 3 years after the initial diagnosis. The patient showed remarkable clinical and radiographic improvement in tumor burden after treatment. Best corrected visual acuity improved from 20/50 to 20/20- in his amblyopic eye. Relative proptosis of the affected eye also improved from 4mm to 2mm on Hertel measurements, which allowed for consistent glasses wear. Adverse effects from the treatment were limited to an acneiform rash, which resolved following dose reduction according to the FDA dosing guidelines.

Topical adapalene for the treatment of follicular conjunctivitis due to periocular molluscum contagiosum in children.

PURPOSE: Periocular molluscum contagiosum can cause a chronic secondary follicular conjunctivitis or keratoconjunctivitis that rarely leads to corneal scarring and visual impairment. We describe two cases of follicular conjunctivitis due to periocular molluscum contagiosum that were successfully treated with topical adapalene 0.1%. OBSERVATIONS: Case 1 is a 9-year old female with a history of leg molluscum contagiosum who presented with three 1mm flesh-colored umbilicated papules on the periocular skin of the right eye with associated follicular conjunctivitis and diffuse corneal punctate epithelial erosions. Ocular symptoms were persistent for 6 months. Case 2 is a 4-year old female with a 3-month history of right periocular bumps and one month of conjunctival redness with eyelid edema. Examination revealed umbilicated flesh colored nodules on the right upper and lower eyelids with associated trace conjunctival injection. Both patients experienced rapid resolution of both eyelid involvement and conjunctivitis following the use of twice daily topical adapalene 0.1% to the eyelid lesions, with no reported side effects. CONCLUSIONS AND IMPORTANCE: Topical adapalene 0.1% is a cost-effective, convenient, and non-toxic over-the-counter retinoid cream that should be considered for first-line therapy in the treatment of periocular molluscum contagiosum and any associated conjunctivitis.

Ocular phenotype in a patient with PAX2 gene mutation-associated papillorenal syndrome.

BACKGROUND: Papillorenal syndrome is an autosomal dominant disorder associated with mutations in the gene PAX2 and often presents with characteristic and specific optic disc findings, frequently with renal dysplasia. In at least half of cases, an identifiable mutation in the PAX2 gene can be detected. We report the ocular findings in a second case of papillorenal syndrome with the c.350 G > C (p.Arg117Pro) mutation detected within the PAX2 gene. METHODS: A case report of papillorenal syndrome due to PAX2 mutation. Complete ophthalmologic examination was performed as well as color fundus photography, fundus autofluorescence, and optical coherence tomography (OCT). Genetic testing was performed using a next-generation sequencing with CNV calling (NGS-CNV) panel test containing 55 genes associated with nephrotic syndrome or focal segmental glomerulosclerosis. RESULTS: An 11-year-old boy who presented with hypertension and proteinuria was found to have stage IV chronic kidney disease. Presenting visual acuity was 20/25 in the right eye and 20/20 in the left eye. The fundus exam showed bilateral centrally excavated optic discs with absent central retinal vessels and a compensatory multiplicity of cilioretinal vessels, characteristic and specific for papillorenal syndrome. OCT showed outer retinal atrophy and macular schisis. Genetic testing identified the likely pathogenic c.350 G > C (p.Arg117Pro) mutation in PAX2. CONCLUSIONS: We report the first description, to our knowledge, of the clinical presentation, ocular and systemic findings, and ophthalmic imaging in an individual with papillorenal syndrome associated with the PAX2 c.350 G > C (p.Arg117Pro) mutation. Our case adds to the current understanding of papillorenal syndrome and demonstrates that this condition is associated with a pathognomonic optic disc appearance and significant renal disease.

Ankyrin-B p.S646F undergoes increased proteasome degradation and reduces cell viability in the H9c2 rat ventricular cardiomyoblast cell line.

Ankyrin-B (AnkB) is scaffolding protein that anchors integral membrane proteins to the cardiomyocyte cytoskeleton. We recently identified an AnkB variant, AnkB p.S646F (ANK2 c.1937 C>T) associated with a phenotype ranging from predisposition for cardiac arrhythmia to cardiomyopathy. AnkB p.S646F exhibited reduced expression levels in the H9c2 rat ventricular-derived cardiomyoblast cell line relative to wildtype AnkB. Here, we demonstrate that AnkB is regulated by proteasomal degradation and proteasome inhibition rescues AnkB p.S646F expression levels in H9c2 cells, although this effect is not conserved with differentiation. We also compared the impact of wildtype AnkB and AnkB p.S646F on cell viability and proliferation. AnkB p.S646F expression resulted in decreased cell viability at 30 h after transfection, whereas we observed a greater proportion of cycling, Ki67-positive cells at 48 h after transfection. Notably, the number of GFP-positive cells was low and was consistent between wildtype AnkB and AnkB p.S646F expressing cells, suggesting that AnkB and AnkB p.S646F affected paracrine communication between H9c2 cells differentially. This work reveals that AnkB levels are regulated by the proteasome and that AnkB p.S646F compromises cell viability. Together, these findings provide key new insights into the putative cellular and molecular mechanisms of AnkB-related cardiac disease.

Ankyrin B and Ankyrin B variants differentially modulate intracellular and surface Cav2.1 levels.

Ankyrin B (AnkB) is an adaptor and scaffold for motor proteins and various ion channels that is ubiquitously expressed, including in the brain. AnkB has been associated with neurological disorders such as epilepsy and autism spectrum disorder, but understanding of the underlying mechanisms is limited. Cav2.1, the pore-forming subunit of P/Q type voltage gated calcium channels, is a known interactor of AnkB and plays a crucial role in neuronal function. Here we report that wildtype AnkB increased overall Cav2.1 levels without impacting surface Cav2.1 levels in HEK293T cells. An AnkB variant, p.S646F, which we recently discovered to be associated with seizures, further increased overall Cav2.1 levels, again with no impact on surface Cav2.1 levels. AnkB p.Q879R, on the other hand, increased surface Cav2.1 levels in the presence of accessory subunits α2δ1 and ß4. Additionally, AnkB p.E1458G decreased surface Cav2.1 irrespective of the presence of accessory subunits. In addition, we found that partial deletion of AnkB in cortex resulted in a decrease in overall Cav2.1 levels, with no change to the levels of Cav2.1 detected in synaptosome fractions. Our work suggests that depending on the particular variant, AnkB regulates intracellular and surface Cav2.1. Notably, expression of the AnkB variant associated with seizure (AnkB p.S646F) caused further increase in intracellular Cav2.1 levels above that of even wildtype AnkB. These novel findings have important implications for understanding the role of AnkB and Cav2.1 in the regulation of neuronal function in health and disease.

Pannexin 1 Regulates Network Ensembles and Dendritic Spine Development in Cortical Neurons.

Dendritic spines are the postsynaptic targets of excitatory synaptic inputs that undergo extensive proliferation and maturation during the first postnatal month in mice. However, our understanding of the molecular mechanisms that regulate spines during this critical period is limited. Previous work has shown that pannexin 1 (Panx1) regulates neurite growth and synaptic plasticity. We therefore investigated the impact of global Panx1 KO on spontaneous cortical neuron activity using Ca2+ imaging and in silico network analysis. Panx1 KO increased both the number and size of spontaneous co-active cortical neuron network ensembles. To understand the basis for these findings, we investigated Panx1 expression in postnatal synaptosome preparations from early postnatal mouse cortex. Between 2 and 4 postnatal weeks, we observed a precipitous drop in cortical synaptosome protein levels of Panx1, suggesting it regulates synapse proliferation and/or maturation. At the same time points, we observed significant enrichment of the excitatory postsynaptic density proteins PSD-95, GluA1, and GluN2a in cortical synaptosomes from global Panx1 knock-out mice. Ex vivo analysis of pyramidal neuron structure in somatosensory cortex revealed a consistent increase in dendritic spine densities in both male and female Panx1 KO mice. Similar findings were observed in an excitatory neuron-specific Panx1 KO line (Emx1-Cre driven; Panx1 cKOE) and in primary Panx1 KO cortical neurons cultured in vitro. Altogether, our study suggests that Panx1 negatively regulates cortical dendritic spine development.

An Interesting Case of Gradenigo Syndrome.

Gradenigo syndrome is a rare complication of acute otitis media infections, and early diagnosis and treatment of the condition are imperative. In this report, we present a case of a 22-month-old girl who developed acute, acquired esotropia associated with recurrent episodes of otitis media, which resolved after antibiotic treatment. To our knowledge, our patient is one of the youngest children reported in the literature to present with presumed Gradenigo syndrome and the only case of recurrent episodes of acquired esotropia and concurrent otitis media within the short time span of 1 month. We hope to add new information to the existing literature and to aid in the understanding of the pathophysiology and management of this condition.

Probenecid Disrupts a Novel Pannexin 1-Collapsin Response Mediator Protein 2 Interaction and Increases Microtubule Stability.

Neurite formation relies on finely-tuned control of the cytoskeleton. Here we identified a novel protein-protein interaction between the ion and metabolite channel protein Pannexin 1 (Panx1) and collapsin response mediator protein 2 (Crmp2), a positive regulator of microtubule polymerization and stabilization. Panx1 and Crmp2 co-precipitated from both Neuro-2a (N2a) cells and mouse ventricular zone (VZ) tissue. In vitro binding assays between purified proteins revealed the interaction occurs directly between the Panx1 C-terminus (Panx1 CT) and Crmp2. Because Crmp2 is a well-established microtubule-stabilizing protein, and we previously observed a marked increase in neurite formation following treatment with the Panx1 blocker, probenecid, in N2a cells and VZ neural precursor cells (NPCs), we investigated the impact of probenecid on the Panx1-Crmp2 interaction. Probenecid treatment significantly disrupted the Panx1-Crmp2 interaction by both immunoprecipitation (IP) and proximity ligation analysis, without altering overall Crmp2 protein expression levels. In the presence of probenecid, Crmp2 was concentrated at the distal ends of growing neurites. Moreover, probenecid treatment increased tubulin polymerization and microtubule stability in N2a cells. These results reveal that probenecid disrupts a novel interaction between Panx1 and the microtubule stabilizer, Crmp2, and also increases microtubule stability.

Partial tendon recession for small-angle vertical strabismus.

PURPOSE: To evaluate the effectiveness of the partial tendon recession procedure in correcting small-angle vertical deviations. METHODS: The medical records of patients who underwent partial tendon recession (one pole) were reviewed retrospectively. Orthophoria was the primary outcome success criterion; residual deviation, torsion, and the dose-response relationship were also evaluated. A secondary analysis was performed on subsets of patients with thyroid eye disease (TED) and those with procedures on a muscle that had previous surgery. RESULTS: A total of 53 procedures in 44 patients (average age, 58 years; age range 8-88 years) were evaluated. The mean preoperative vertical deviation was 4.3Δ ± 1.8Δ (range, 2Δ-9Δ); the mean postoperative vertical deviation was 0Δ ± 2.3Δ. The mean response to surgery was 1.5Δ/mm. In the entire cohort, 62% of the procedures resulted in orthophoria, but 82% of patients had resolution of vertical diplopia with a single procedure. In TED patients, 60% of the procedures resulted in orthophoria, whereas only 29% of procedures on previously operated muscles resulted in orthophoria. CONCLUSIONS: Partial tendon recession of vertical rectus muscles reliably corrects small vertical deviations. This is equally true for patients with TED, but results are less predictable with reoperated muscles.

Evaluating Efficacy of Aflibercept in Refractory Exudative Age-Related Macular Degeneration With OCT Segmentation Volumetric Analysis.

BACKGROUND AND OBJECTIVE: To use automated segmentation software to analyze spectral-domain optical coherence tomography (SD-OCT) scans and evaluate the effectiveness of aflibercept (Eylea; Regeneron, Tarrytown, NY) in the treatment of patients with exudative age-related macular degeneration (AMD) refractory to other treatments. PATIENTS AND METHODS: Retrospective chart review of 16 patients refractory to bevacizumab (Avastin; Genentech, South San Francisco, CA)/ranibizumab (Lucentis; Genentech, San Francisco, CA) treatment was conducted. Visual acuity, central foveal thickness (CFT), maximum fluid height, pigment epithelial detachment (PED) volume, sub-retinal fluid (SRF) volume, fluid-free time interval, and adverse effects were evaluated. Automated segmentation analysis was used to quantify improvement. RESULTS: With aflibercept treatment, there was a statistically significant improvement in visual acuity by 1 line (P = .020), in CFT by 74.02 µm (P = .001), and in maximum fluid height by 31.9 µm (P= .011). Total PED and SRF volume also decreased significantly by 1.50 µm(3) × 10(8) µm(3) (P = .013). Anatomic improvement was confirmed by automated segmentation analysis. CONCLUSION: This study demonstrates utility of automated segmentation software in quantifying anatomic improvement with aflibercept treatment in exudative AMD refractory to other anti-vascular endothelial growth factor treatments.