Decellularization of Porcine and Primate Optic Nerve Lamina

The optic nerve lamina cribrosa is a mesh-like collagenous structure consisting of an extracellular matrix with varying porosity and glial cell distribution through which axons of retinal ganglion cells travel en route to the lateral geniculate nucleus. There has been significant interest in its structure with respect to its possible role in the pathophysiology of glaucomatous optic neuropathy. Our goal was to decellularize porcine and primate lamina to evaluate for a potential role as a three-dimensional scaffold for stem cell growth, regeneration, and delivery

Reconstruction Of An Outer Retina Using Electrospun Polycaprolactone (pcl) And Cells Derived From Human Embryonic Stem Cells.

As a step towards engineering an outer retina suitable for transplantation, we designed a biocompatible, biodegradable scaffold that allows retinal progenitor cells (RPCs) to form flat, laminar structures. The scaffold minimizes the exposure of retinal progenitors to extracellular matrix components that are not found in the retina, and enables co-culture with the retinal pigment epithelium. Scaffolds were formed from electrospun fibers of polycaprolactone (PCL). Scaffold thickness was varied by increasing the duration of collection during electrospinning; porosity and pore size distribution was adjusted by varying polymer concentration in solution. The porosity and thickness of the sheets were varied to optimize cell to cell contact formation and PCL degradation rate, respectively. RPCs derived from human embryonic stem cells (hESC-derived RPCs) were cultured to form neurospheres. Dissociated neurospheres were seeded onto +/- laminin coated PCL sheets in normal or low O2 incubators, and maintained in two types of serum free medium. Fluorescence labeling and confocal microscopy were used to assess tissue morphology. Individual PCL fibers were ~3 ìm thick, sheets varied from 20-200 ìm in thickness, and pores ranged from 5-100 ìm in diameter. The scaffolds degraded over 4-7 weeks. Scaffolds with pores 25-50 ìm in diameter were subsequently chosen for culture experiments. Biomechanical strength testing estimated a Young\u27s modulus of 0.071 megapascals (MPa). Confocal imaging confirmed that the RPCs penetrated the thickness of the scaffold irrespective of laminin coating and O2 level, and continued to express retinal markers such as Pax6, recoverin, and N-cadherin, with heightened expression in the differentiation medium. Cells adhered uniformly to laminin-coated PCL, but formed aggregates on uncoated PCL. Staining for the proliferative marker, Ki67, indicated active cell division in both medium types and O2 levels. Preliminary RPE: RPC co-culture experiments with laminin coated PCL in low oxygen conditions revealed polarization of N-cadherin, with concomitant stress fiber formation in the RPE monolayer. Overall, electrospun PCL polymers sustained the differentiated properties acquired by neurospheres and appear to be suitable scaffolds for reconstructing an outer retinal layer

Malignant solitary fibrous tumor of the orbit: Spectrum of histologic features

Purpose: Primary malignant solitary fibrous tumor (SFT) of the orbit is a rare spindle cell neoplasm that requires excisional biopsy for histopathological diagnosis. We present a clinical case using contemporary immunohistochemical stains, report on the latest World Health Organization classification, and provide a review of the literature. Observations: Report of a single case of a 65 year old male who presented with right-sided proptosis, limited adduction, ptosis, lateral globe displacement, and cheek festooning. Neuroimaging revealed a 2.2 cm, extraconal heterogeneous mass that diffusely enhanced. En-bloc tumor resection confirmed SFT malignancy based upon nuclear atypia, hypercellularity, and increased mitotic activity (13 mitotic figures/10 high powered fields). Ki-67 showed 2% nuclear staining in the benign tumor and 10–15% staining in the malignant counterpart. Immunohistochemical analysis revealed diffuse Stat6 positivity, CD 34 positivity with partial lack of staining within the malignant portion, S-100 positivity in the malignant portion, and overall negativity for CAM 5.2, desmin, actin, CD 31, and CD 117. Conclusions and importance: Immunoprofiling is helpful to making the diagnosis of malignant solitary fibrous tumor of the orbit. Complete tumor resection continues to be the preferred treatment. The behavior of extrathoracic SFT is unpredictable, and patients with SFT in all locations require careful, long-term follow-up

Microbiology and Biofilm Trends of Silicone Lacrimal Implants: Comparing Infected Versus Routinely Removed Stents

To investigate the pathogens and biofilms responsible for clinically significant infection of silicone stents implanted within the lacrimal system. Retrospective review of culture results and patient demographics for all silicone lacrimal stents removed early for clinically significant infection and sent to the Bascom Palmer Microbiology Laboratory through the end of year 2010. As a control, routinely removed, clinically noninfected stents from the same institution were prospectively sent for culture over a 6-month period. Four clinically infected and 6 clinically noninfected stents showing mucus within the lumen at removal were sent for scanning electron microscopy. Images were randomized and graded by a microbiologist for the presence of organisms, matrix deposits, organisms within matrix, and overall impression of significant biofilm formation. Nineteen stents were included in the study; 100% of clinically infected (n = 10) and noninfected (n = 9) stents were culture positive. Culture positivity for nontuberculous mycobacterium was found in 90% of infected stents and none of the noninfected stents (p < 0.001). Of infected stents, 50% grew Gram-positive organisms compared with 89% of noninfected stents (p = 0.07). Fifty percent of infected versus 67% of noninfected stents were culture positive for Gram-negative organisms (p = 0.46). Electron microscopy of stents revealed organisms consistent with culture results (size, shape) in planktonic and biofilm form. Masked observer image grading revealed a statistically significant higher amount of organism and biofilm on infected versus noninfected specimen. Nontuberculous mycobacteria comprise the primary pathogens responsible for clinically significant infection of silicone stents in the lacrimal system in South Florida. Robust biofilm production by this organism likely plays a role in pathogenesis. Further research into biofilm-related lacrimal implant infection may aid in the development of useful prevention and treatment strategies

A comparison of proptosis reduction with teprotumumab versus surgical decompression based on fat-to-muscle ratio in thyroid eye disease

PurposeTo explore if orbital fat-to-muscle ratio (FMR) is predictive of whether surgical decompression or teprotumumab leads to greater proptosis reduction in thyroid eye disease (TED).MethodsA single-center retrospective cohort study comparing surgical decompression with teprotumumab according to FMR. All TED patients completing an 8-dose course of teprotumumab between January 2020 and September 2022 and all patients undergoing bony orbital decompression from January 2017 to December 2019 were included. Subjects were excluded if they were &lt;18 years, received both surgical decompression and teprotumumab, or lacked orbital imaging. The primary exposure variable was teprotumumab or surgical decompression. The secondary exposure variable was baseline FMR. The primary outcome measure was change in proptosis (mm).ResultsThirty-eight patients, mean age 53.5 years (±11.4), were included in the teprotumumab group and 160 patients, mean age 48 years (±11.1), in the surgical group. Average proptosis reduction after teprotumumab and surgical decompression was 3 mm (±1.44) and 5 mm (±1.75), respectively. The FMR was stratified at the median of 1.80. In subjects with FMR &lt; 1.80, teprotumumab showed equivalent proptosis reduction compared to surgical decompression, -0.33 mm (SE 1.32) p = .802. In subjects with FMR ≥ 1.80, surgical decompression led to significantly more proptosis reduction than teprotumumab, 3.01 mm (SE 0.54), p &lt; .001.ConclusionsBaseline FMR can be used to counsel patients as to proptosis reduction with teprotumumab versus surgery. Subjects with low FMR obtain comparable proptosis reduction with teprotumumab or surgery, whereas high FMR is associated with more significant proptosis reduction following surgery over teprotumumab

Predictive Modeling of New-Onset Postoperative Diplopia Following Orbital Decompression for Thyroid Eye Disease

PurposeTo identify risk factors for the development of new-onset, postoperative diplopia following orbital decompression surgery based on patient demographics, clinical exam characteristics, radiographic parameters, and surgical techniques.MethodsWe conducted a multi-center retrospective chart review of patients who underwent orbital decompression for thyroid eye disease (TED). Patient demographics, including age, gender, smoking history, preoperative exophthalmometry, clinical activity score (CAS), use of peribulbar and/or systemic steroids, and type of orbital decompression were reviewed. Postoperative diplopia was determined at a minimum of 3 months postoperatively and before any further surgeries. Cross-sectional area ratios of each extraocular muscle to orbit and total fat to orbit were calculated from coronal imaging in a standard fashion. All measurements were carried out using PACS imaging software. Multivariable logistic regression modeling was performed using Stata 14.2 (StataCorp, College Station, TX).ResultsA total of 331 patients without preoperative diplopia were identified. At 3 months postoperatively, 249 patients had no diplopia whereas 82 patients developed diplopia. The average postoperative follow-up was 22 months (range 3-156) months. Significant preoperative clinical risk factors for postoperative diplopia included older age at surgery, proptosis, use of peribulbar or systemic steroids, elevated clinical activity score, and presence of preoperative compressive optic neuropathy. Imaging findings of enlarged cross-sectional areas of each rectus muscle to the overall orbital area also conferred a significant risk of postoperative diplopia. Regarding surgical factors, postoperative diplopia was more common among those undergoing medial wall decompression, bilateral orbital surgery, and balanced decompression, whereas endoscopic medial wall decompression was found to be relatively protective.ConclusionsThis study identifies risk factors associated with the development of diplopia following orbital decompression using multivariable data. This study demonstrates that several characteristics including age, clinical activity score, the cross-sectional muscle to orbit ratios, in addition to the type of orbital decompression surgery, are predictive factors for the development of new-onset postoperative diplopia