Bell's palsy is a common cranial neuropathy causing acute unilateral lower motor neuron facial paralysis. Immune, infective and ischaemic mechanisms are all potential contributors to the development of Bell's palsy, but the precise cause remains unclear. Advancements in the understanding of intra-axonal signal molecules and the molecular mechanisms underpinning Wallerian degeneration may further delineate its pathogenesis along with in vitro studies of virus-axon interactions. Recently published guidelines for the acute treatment of Bell's palsy advocate for steroid monotherapy, although controversy exists over whether combined corticosteroids and antivirals may possibly have a beneficial role in select cases of severe Bell's palsy. For those with longstanding sequaelae from incomplete recovery, aesthetic, functional (nasal patency, eye closure, speech and swallowing) and psychological considerations need to be addressed by the treating team. Increasingly, multidisciplinary collaboration between interested clinicians from a wide variety of subspecialties has proven effective. A patient centred approach utilising physiotherapy, targeted botulinum toxin injection and selective surgical intervention has reduced the burden of long-term disability in facial palsy.
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2015
Lymphedema is caused by defective drainage of the lymphatic system. In Melkersson-Rosenthal syndrome, involvement is predominantly of the lumens with blockage of lymphatic channels by histiocytic-epithelioid cell clusters accompanied by dermal granulomas and lymphocytes. It is a localized, painless, nonitching, and nonpitting form of lymphedema. Besides the eyelids, the disease can cause lip edema, facial palsy, and/or fissured tongue. It is rare and has received little attention in the ophthalmic literature, either in its complete triadic form, or more frequently, in its monosymptomatic forms. Pathogenesis is not well understood, and there is no effective therapy. The authors describe a case of Melkesson-Rosenthal syndrome in a 45-year-old Hispanic man with isolated unilateral upper eyelid edema. Histopathological and immunohistochemical evaluations of an eyelid biopsy specimen revealed intravascular and extravascular clusters of histiocytic-epithelioid cells that were CD68/163-positive. Variable numbers of mostly T-lymphocytes were found in the epidermis, dermis, and orbicularis muscle and by virtue of the associated granulomas established the diagnosis of Melkersson-Rosenthal syndrome. CD4 helper and CD8 suppressor T-lymphocytes were equally represented. CD20 B-lymphocytes were exceedingly sparse. Conspicuous CD1a-positive Langerhans' cells were present in the epidermis, sometimes formed subepithelial loose aggregates and were also incorporated in the granulomas. The differential diagnosis includes the far more common condition of acne rosacea. Management of Melkersson-Rosenthal syndrome, and of angioedema in general, is reviewed.
PURPOSE: To report the technique and result of keratopigmentation using a femtosecond laser for the treatment of functional visual disabilities caused by peripheral iridectomies. DESIGN: Case report. METHODS: Two eyes of 2 patients underwent femtosecond laser-assisted keratopigmentation (FLAK) for moderate to severe visual dysfunction secondary to peripheral iridectomies. The main outcomes measures of the study were changes in visual-related symptoms, cosmesis, and intraoperative surgical complications. RESULTS: Following FLAK, the visual-related symptoms (ghosting, glare, and monocular diplopia) improved in both cases with significant improvement to total elimination of symptoms. No patient lost any lines of visual acuity, and no significant complications were observed during the follow-up period. The cosmetic appearance was reported as very good. CONCLUSIONS: FLAK is minimally invasive and results in a significant decrease in the subjective glare and photophobia and even in resolution of monocular diplopia. The cosmetic outcome was also favorable. This technique allows surgeons to correct visual disabilities associated with iris defects with a high success rate while avoiding more aggressive intraocular surgery.
PURPOSE: Retinitis pigmentosa is a Mendelian disease with a very elevated genetic heterogeneity. Most mutations are responsible for less than 1% of cases, making molecular diagnosis a multigene screening procedure. In this study, we assessed whether direct testing of specific alleles could be a valuable screening approach in cases characterized by prevalent founder mutations. METHODS: We screened 275 North American patients with recessive/isolate retinitis pigmentosa for two mutations: an Alu insertion in the MAK gene and the p.Lys42Glu missense in the DHDDS gene. All patients were unrelated; 35 reported Jewish ancestry and the remainder reported mixed ethnicity. RESULTS: We identified the MAK and DHDDS mutations homozygously in only 2.1% and 0.8%, respectively, of patients of mixed ethnicity, but in 25.7% and 8.6%, respectively, of cases reporting Jewish ancestry. Haplotype analyses revealed that inheritance of the MAK mutation was attributable to a founder effect. CONCLUSION: In contrast to most mutations associated with retinitis pigmentosa-which are, in general, extremely rare-the two alleles investigated here cause disease in approximately one-third of North American patients reporting Jewish ancestry. Therefore, their screening constitutes an alternative procedure to large-scale tests for patients belonging to this ethnic group, especially in time-sensitive situations.Genet Med 17 4, 285-290.
BACKGROUND: Graft failure because of immune rejection remains a significant problem in organ transplantation, and lymphatic and blood vessels are important components of the afferent and efferent arms of the host alloimmune response, respectively. We compare the effect of antihemangiogenic and antilymphangiogenic therapies on alloimmunity and graft survival in a murine model of high-risk corneal transplantation. METHODS: Orthotopic corneal transplantation was performed in hemevascularized and lymph-vascularized high-risk host beds, and graft recipients received subconjunctival vascular endothelial growth factor (VEGF)-trap, anti-VEGF-C, sVEGFR-3, or no treatment, beginning at the time of surgery. Fourteen days after transplantation, graft hemeangiogenesis and lymphangiogenesis were evaluated by immunohistochemistry. The frequencies of Th1 cells in regional lymphoid tissue and graft-infiltrating immune cells were evaluated by flow cytometry. Long-term allograft survival was compared using Kaplan-Meier curves. RESULTS: VEGF-trap significantly decreased graft hemangiogenesis as compared to the control group and was most effective in reducing the frequency of graft-infiltrating immune cells. Anti-VEGF-C and sVEGFR3 significantly decreased graft lymphangiogenesis and lymphoid Th1 cell frequencies as compared to control. VEGF-trap (72%), anti-VEGF-C (25%), and sVEGFR-3 (11%) all significantly improved in the 8-week graft survival compared to control (0%), although VEGF-trap was significantly more effective than both anti-VEGF-C (P < 0.05) and sVEGFR-3 (P < 0.05). CONCLUSION: In a clinically relevant model of high-risk corneal transplantation in which blood and lymphatic vessels are present and treatment begins at the time of transplantation, VEGF-trap is significantly more effective in improving long-term graft survival as compared to anti-VEGF-C and sVEGFR-3, but all approaches improve survival when compared to untreated control.
Organismal development requires the precise coordination of genetic programs to regulate cell fate and function. MEF2 transcription factors (TFs) play essential roles in this process but how these broadly expressed factors contribute to the generation of specific cell types during development is poorly understood. Here we show that despite being expressed in virtually all mammalian tissues, in the retina MEF2D binds to retina-specific enhancers and controls photoreceptor cell development. MEF2D achieves specificity by cooperating with a retina-specific factor CRX, which recruits MEF2D away from canonical MEF2 binding sites and redirects it to retina-specific enhancers that lack the consensus MEF2-binding sequence. Once bound to retina-specific enhancers, MEF2D and CRX co-activate the expression of photoreceptor-specific genes that are critical for retinal function. These findings demonstrate that broadly expressed TFs acquire specific functions through competitive recruitment to enhancers by tissue-specific TFs and through selective activation of these enhancers to regulate tissue-specific genes.
The ability to form biofilms in a variety of environments is a common trait of bacteria, and may represent one of the earliest defenses against predation. Biofilms are multicellular communities usually held together by a polymeric matrix, ranging from capsular material to cell lysate. In a structure that imposes diffusion limits, environmental microgradients arise to which individual bacteria adapt their physiologies, resulting in the gamut of physiological diversity. Additionally, the proximity of cells within the biofilm creates the opportunity for coordinated behaviors through cell-cell communication using diffusible signals, the most well documented being quorum sensing. Biofilms form on abiotic or biotic surfaces, and because of that are associated with a large proportion of human infections. Biofilm formation imposes a limitation on the uses and design of ocular devices, such as intraocular lenses, posterior contact lenses, scleral buckles, conjunctival plugs, lacrimal intubation devices and orbital implants. In the absence of abiotic materials, biofilms have been observed on the capsule, and in the corneal stroma. As the evidence for the involvement of microbial biofilms in many ocular infections has become compelling, developing new strategies to prevent their formation or to eradicate them at the site of infection, has become a priority.
We report a case of a 57-year-old man who presented with decreased visual acuity in the left eye secondary to nonarteritic anterior ischemic optic neuropathy (NAION) while on therapy with interferon-α for hepatitis C. Fundus fluorescein angiography revealed late leakage of both optic discs, consistent with bilateral disease. One week later, the patient developed clinical signs and symptoms consistent with NAION in the fellow eye. Fluorescein angiography may play an important role in identifying subclinical NAION in patients taking interferon-α.
The paucity of animal models exhibiting full pathology of diabetic retinopathy (DR) has impeded understanding of the pathogenesis of DR and the development of therapeutic interventions. Here we investigated if hyperhexosemic marmosets (Callithrix jacchus) develop characteristic retinal vascular lesions including macular edema (ME), a leading cause of vision loss in DR. Marmosets maintained on 30% galactose (gal)-rich diet for two years were monitored for retinal vascular permeability, development of ME, and morphological characteristics including acellular capillaries (AC) and pericyte loss (PL), vessel tortuosity, and capillary basement membrane (BM) thickness. Excess vascular permeability, increased number of AC and PL, vascular BM thickening, and increased vessel tortuosity were observed in the retinas of gal-fed marmosets. Optical coherence tomography (OCT) images revealed significant thickening of the retinal foveal and the juxtafoveal area, and histological analysis showed incipient microaneurysms in retinas of gal-fed marmosets. Findings from this study indicate that hyperhexosemia can trigger retinal vascular changes similar to those seen in human DR including ME and microaneurysms. The striking similarities between the marmoset retina and the human retina, and the exceptionally small size of the monkey, offer significant advantages to this primate model of DR.
PURPOSE: Corneal wound healing is a highly regulated process that requires the proliferation and migration of epithelial cells and interactions between epithelial cells and stromal fibroblasts. Compounds that can be applied topically to the ocular surface and that have the capability of activating corneal epithelial cells to proliferate and/or migrate would be useful to promote corneal wound healing. We hypothesize that human growth hormone (HGH) will activate signal transducers and activators of transcription-5 (STAT5) signaling and promote corneal wound healing by enhancing corneal epithelial cell and fibroblast proliferation and/or migration in vitro. The purpose of this study was to test these hypotheses. METHODS: We studied cell signaling, proliferation, and migration using an immortalized human corneal epithelial cell line and primary human corneal fibroblasts in vitro. We also examined whether insulin-like growth factor-1 (IGF-1), a hormone known to mediate many of HGH's growth promoting actions, may play a role in this effect. RESULTS: We show that HGH activates STAT5 signaling and promotes corneal epithelial cell migration in vitro. The migratory effect requires an intact communication between corneal epithelia and fibroblasts and is not mediated by IGF-1. CONCLUSIONS: HGH may represent a topical therapeutic to promote corneal epithelial wound healing. This warrants further investigation.
BACKGROUND: Retinopathy of prematurity (ROP) is a vision-threatening disease in premature infants. Serum adiponectin (APN) concentrations positively correlate with postnatal growth and gestational age, important risk factors for ROP development. Dietary ω-3 (n-3) long-chain polyunsaturated fatty acids (ω-3 LCPUFAs) suppress ROP and oxygen-induced retinopathy (OIR) in a mouse model of human ROP, but the mechanism is not fully understood. OBJECTIVE: We examined the role of APN in ROP development and whether circulating APN concentrations are increased by dietary ω-3 LCPUFAs to mediate the protective effect in ROP. DESIGN: Serum APN concentrations were correlated with ROP development and serum ω-3 LCPUFA concentrations in preterm infants. Mouse OIR was then used to determine whether ω-3 LCPUFA supplementation increases serum APN concentrations, which then suppress retinopathy. RESULTS: We found that in preterm infants, low serum APN concentrations positively correlate with ROP, and serum APN concentrations positively correlate with serum ω-3 LCPUFA concentrations. In mouse OIR, serum total APN and bioactive high-molecular-weight APN concentrations are increased by ω-3 LCPUFA feed. White adipose tissue, where APN is produced and assembled in the endoplasmic reticulum, is the major source of serum APN. In mouse OIR, adipose endoplasmic reticulum stress is increased, and APN production is suppressed. ω-3 LCPUFA feed in mice increases APN production by reducing adipose endoplasmic reticulum stress markers. Dietary ω-3 LCPUFA suppression of neovascularization is reduced from 70% to 10% with APN deficiency. APN receptors localize in the retina, particularly to pathologic neovessels. CONCLUSION: Our findings suggest that increasing APN by ω-3 LCPUFA supplementation in total parental nutrition for preterm infants may suppress ROP.
Disruption of the MECP2 gene leads to Rett syndrome (RTT), a severe neurological disorder with features of autism. MECP2 encodes a methyl-DNA-binding protein that has been proposed to function as a transcriptional repressor, but despite numerous mouse studies examining neuronal gene expression in Mecp2 mutants, no clear model has emerged for how MeCP2 protein regulates transcription. Here we identify a genome-wide length-dependent increase in gene expression in MeCP2 mutant mouse models and human RTT brains. We present evidence that MeCP2 represses gene expression by binding to methylated CA sites within long genes, and that in neurons lacking MeCP2, decreasing the expression of long genes attenuates RTT-associated cellular deficits. In addition, we find that long genes as a population are enriched for neuronal functions and selectively expressed in the brain. These findings suggest that mutations in MeCP2 may cause neurological dysfunction by specifically disrupting long gene expression in the brain.
An unprecedented pigmented caruncular apocrine hidrocystoma with the additional feature of an oncocytic transformation of the cyst's lining cells is reported. Over a year, a 79-year-old woman developed a centrally pigmented lesion of her right caruncle with translucent borders. Because of concern about a melanoma, a carunculectomy with adjunctive cryotherapy and placement of an amniotic membrane graft were performed, and the excised specimen was evaluated microscopically. A large cyst dominated the caruncle and was lined by an inner layer of columnar eosinophilic and granular cells with an outer, interrupted layer of flattened myoepithelial cells. Phosphotungstic acid hematoxylin staining disclosed myriad cytoplasmic, dot-like mitochondria signifying an oncocytic change. Immunohistochemistry revealed gross cystic fluid disease protein-15 and cytokeratin 7-positivity indicative of apocrine differentiation. Oncocytic change is characteristically encountered in lacrimal ductal cysts and tumors.
BACKGROUND/AIMS: To evaluate ex vivo biomechanical and enzymatic digestion resistance differences between standard myopic laser in-situ keratomileusis (LASIK) compared with LASIK+CXL, in which high-irradiance cross-linking (CXL) is added. METHODS: Eight human donor corneas were subjected to femtosecond-assisted myopic LASIK. Group A (n=4) served as a control group (no CXL). The corneas in LASIK+CXL group B were subjected to concurrent prophylactic high-irradiance CXL (n=4). Saline-diluted (0.10%) riboflavin was instilled on the stroma, subsequently irradiated with UV-A through the repositioned flap. The cornea stroma and flap specimens were separately subjected to transverse biaxial resistance measurements; biomechanical differences were assessed via stress and Young's shear modulus. Subsequently, the specimens were subjected to enzymatic degradation. RESULTS: For the corneal stroma specimen, stress at 10% strain was 128±11 kPa for control group A versus 293±20 kPa for the LASIK+CXL group B (relative difference Δ=+129%, p<0.05). The stress in group B was also increased at 20% strain by +68% (p<0.05). Shear modulus in group B was increased at 10% strain by +79%, and at 20% strain by +48% (both statistically significant, p<0.05). The enzymatic degradation time to dissolution was 157.5±15.0 min in group A versus 186.25±7.5 min in group B (Δ=+18%, p=0.014). For the flaps, both biomechanical, as well as enzymatic degradation tests showed no significant differences. CONCLUSIONS: LASIK+CXL appears to provide significant increase in underlying corneal stromal rigidity, up to +130%. Additionally, there is significant relevant enzymatic digestion resistance confirmatory to the above. LASIK flaps appear unaffected biomechanically by the LASIK+CXL procedure, suggesting effective CXL just under the flap.
PURPOSE: We explored whether risk factor associations differed by primary open-angle glaucoma (POAG) subtypes defined by visual field (VF) loss pattern (i.e., paracentral or peripheral). METHODS: We included 77,157 women in the Nurses Health Study and 42,773 men in the Health Professionals Follow-up Study (1986-2010) and incident medical-record confirmed cases of paracentral (n=440) and peripheral (n=865) POAG subtypes. We evaluated African-heritage, glaucoma family history, body mass index (BMI), mean arterial blood pressure, diabetes mellitus, physical activity, smoking, caffeine and alcohol intakes. We used competing risk Cox regression analyses modeling age as the metameter and stratified by age, cohort and event type. We sequentially identified factors with the least significant differences in associations with POAG subtypes ("stepwise down" approach with P for heterogeneity [P-het]<0.10 as threshold). RESULTS: BMI was more inversely associated with the POAG paracentral VF loss subtype than the peripheral VF loss subtype (per 10 kg/m2; hazard ratio [HR]=0.67 [95% Confidence Interval [CI]: 0.52, 0.86] vs. HR=0.93 [95% CI: 0.78, 1.10]; P-het=0.03) as was smoking (per 10 pack-years; HR=0.92 [95% CI: 0.87, 0.98] vs. HR=0.98 [95% CI: 0.94, 1.01]; P-het=0.09). These findings were robust in sensitivity analyses using a "stepwise up" approach (identify factors that showed the most significant differences). Non-heterogeneous (p-het>0.10) adverse associations with both POAG subtypes were observed with glaucoma family history, diabetes, African-heritage, greater caffeine intake and higher mean arterial pressure. CONCLUSIONS: These data indicate that POAG with early paracentral VF loss has distinct as well as common determinants compared to POAG with peripheral VF loss.
PURPOSE: To evaluate corneal endothelial cell density (ECD) in patients with dry eye disease (DED) compared to an age-matched control group. DESIGN: Cross-sectional, controlled study. METHODS: This study included 90 eyes of 45 patients with moderate to severe DED (aged 53.7 ± 9.8 years) and 30 eyes of 15 normal controls (aged 50.7 ± 9.8 years). All subjects had a complete ophthalmic evaluation including symptom assessment using the Ocular Surface Disease Index (OSDI) and corneal fluorescein staining. In addition, laser scanning in vivo confocal microscopy was performed to measure the density of the following parameters in the central cornea: endothelial cells, subbasal nerves, and subbasal immune dendritic cells. RESULTS: Corneal ECD was significantly lower in the DED group (2595.8 ± 356.1 cells/mm(2)) than in the control group (2812.7 ± 395.2 cells/mm(2), P = .046). The DED group showed significantly lower corneal subbasal nerve density (17.1 ± 6.9 mm/mm(2)) compared to the control group (24.7 ± 4.4 mm/mm(2), P < .001). Dendritic cell density was significantly higher in the DED group than in the controls (111.7 ± 137.3 vs 32.0 ± 24.4 cells/mm(2), respectively, P = .002). There were statistically significant correlations between corneal ECD and dry eye severity parameters including the OSDI score (rs = -0.26, P = .03), and corneal fluorescein staining (rs = -0.28, P = .008). CONCLUSIONS: There is a significant reduction in corneal ECD in DED that correlates with clinical severity of the disease.
PURPOSE: To report a case of ocular ischemic syndrome presenting as retinal vasculitis in a patient with Moyamoya syndrome. METHODS: A retrospective chart review was conducted to record clinical data including fluorescein angiography, optical coherence tomography, and serologic testing. A review of the literature from 1969 to 2014 of ocular involvement in Moyamoya syndrome was performed. RESULTS: A 51-year-old woman with long history of bilateral retinal vasculitis and refractory cystoid macular edema was eventually diagnosed with Moyamoya syndrome after sustaining a perioperative cerebrovascular accident. Moyamoya syndrome has been associated in the literature with ocular ischemic syndrome, presenting with narrowed retinal arteries, dilated veins, and midperipheral retinal hemorrhages, but retinal vasculitis with cystoid macular edema has not been reported. CONCLUSION: Moyamoya-related ocular ischemic syndrome can present as retinal vascular leakage and macular edema. Ophthalmologists should be cognizant that signs of the disease may be first observed in the eye before manifestations in the cerebrovascular system.
PURPOSE: To report the prevalence and risk factors for retinopathy in African Americans with impaired fasting glucose (IFG) and type 2 diabetes in the Jackson Heart Study and to determine if P-selectin plasma levels are independently associated with retinopathy in this population. DESIGN: Prospective, cross-sectional observational study. METHODS: setting: Community-based epidemiologic study. STUDY POPULATION: Total of 629 patients with type 2 diabetes and 266 participants with impaired fasting glucose. OBSERVATION PROCEDURES: Bilateral, 7-field fundus photographs were scored by masked readers for diabetic retinopathy (DR) level. Covariate data including P-selectin plasma levels and genotypes were collected in a standardized fashion. MAIN OUTCOME MEASURES: Association between risk factors, including P-selectin plasma levels and genotypes, and retinopathy. RESULTS: The prevalences of any retinopathy among participants with IFG and type 2 diabetes were 9.4% and 32.4%, respectively. Among those with type 2 diabetes, in multivariate models adjusted for age, sex, and other traditional risk factors, higher P-selectin levels were associated with any DR (odds ratio = 1.11, 95% confidence interval = 1.02-1.21, P = .02) and proliferative DR (odds ratio = 1.23, 95% confidence interval = 1.03-1.46, P = .02). To further investigate the relationship between P-selectin and DR, we examined the association between P-selectin genotype and DR. Minor allele homozygotes for the variant rs6128 were less likely to develop DR (P after Bonferroni correction = 0.03). CONCLUSIONS: Both serologic and genetic data show an association between P-selectin and DR in the Jackson Heart Study. If confirmed in other studies, this association may provide insight into the pathogenesis of retinopathy.
PURPOSE: A pocket-sized collision warning device equipped with a video camera was developed to predict impending collisions based on time to collision rather than proximity. A study was conducted in a high density obstacle course to evaluate the effect of the device on collision avoidance in people with peripheral field loss (PFL). METHODS: The 41 meter long loop-shaped obstacle course consisted of 46 stationary obstacles from floor to head level, and oncoming pedestrians. Twenty five patients with tunnel vision (n = 13) or hemianopia (n = 12) completed 4 consecutive loops with and without the device, while not using any other habitual mobility aid. Walking direction and device usage order were counterbalanced. Number of collisions and preferred percentage of walking speed (PPWS) were compared within subjects. RESULTS: Collisions were reduced significantly by about 37% (p < 0.001) with the device (Floor-level obstacles were excluded because the device was not designed for them). No patient had more collisions when using the device. While the PPWS also reduced with the device from 52% to 49% (p = 0.053), this did not account for the lower number of collisions, as the changes in collisions and PPWS were not correlated (p = 0.516). CONCLUSIONS: The device may help patients with a wide range of PFL avoid collisions with high-level obstacles and barely affect their walking speed.
Cone photoreceptors function under daylight conditions and are essential for color perception and vision with high temporal and spatial resolution. A remarkable feature of cones is that, unlike rods, they remain responsive in bright light. In rods, light triggers a decline in intracellular calcium, which exerts a well studied negative feedback on phototransduction that includes calcium-dependent inhibition of rhodopsin kinase (GRK1) by recoverin. Rods and cones share the same isoforms of recoverin and GRK1, and photoactivation also triggers a calcium decline in cones. However, the molecular mechanisms by which calcium exerts negative feedback on cone phototransduction through recoverin and GRK1 are not well understood. Here, we examined this question using mice expressing various levels of GRK1 or lacking recoverin. We show that although GRK1 is required for the timely inactivation of mouse cone photoresponse, gradually increasing its expression progressively delays the cone response recovery. This surprising result is in contrast with the known effect of increasing GRK1 expression in rods. Notably, the kinetics of cone responses converge and become independent of GRK1 levels for flashes activating more than ∼1% of cone pigment. Thus, mouse cone response recovery in bright light is independent of pigment phosphorylation and likely reflects the spontaneous decay of photoactivated visual pigment. We also find that recoverin potentiates the sensitivity of cones in dim light conditions but does not contribute to their capacity to function in bright light.
