Optical coherence tomography angiography in Purtscher-like retinopathy associated with dermatomyositis: a case report.

PURPOSE: To describe a multimodal imaging diagnosis of retinopathy in dermatomyositis. CASE PRESENTATION: A 21-year-old white woman with a history of fatigue and a cutaneous rash complained of visual impairment in her left eye. A funduscopic examination showed multiple confluent cotton-wool spots in both eyes. Swept source-optical coherence tomography presented macular edema in both eyes; optical coherence tomography angiography revealed superficial and deep capillary occlusion in all areas affected by cotton-wool spots; and fluorescein angiography showed vascular walls enhancement, veins dilatation, and capillary leakage. After large doses of intravenously administered glucocorticoid therapy, followed by a cyclophosphamide regimen, best corrected visual acuity returned to 20/20 in both eyes. CONCLUSIONS: This case report presents optical coherence tomography angiography clinical findings in a rare case of dermatomyositis-associated retinopathy, remarking the importance of a multi-imaging approach for a correct diagnosis and treatment of eye injuries, in order to avoid serious complications and permanent sequelae.

Aqueous humour flow in the posterior chamber of the eye and its modifications due to pupillary block and iridotomy.

The anterior chamber (AC) and posterior chamber (PC) of the eye are connected through the pupil and are filled with aqueous humour. The aqueous flows from the posterior to the AC at an approximately constant rate, and the intraocular pressure is governed by this rate and the resistance to aqueous outflow. In some patients the iris and lens come into contact, leading to pressure build-up in the PC, peripheral axial shallowing of the AC and, possibly, to angle-closure glaucoma. This can lead to blindness, which may be prevented by surgically creating an iridotomy, that is a hole through the iris to facilitate the flow from the posterior to the AC. The problem of optimal size and location of an iridotomy is still poorly understood. In this article, we study aqueous flow in the PC and investigate how it is modified in the presence of an iridotomy. Our approach is based on the lubrication theory, which allows us to solve the problem semi-analytically. We treat the iridotomy as a point sink and assume that the flux through it is proportional to the pressure. We find that the ideal size and location of an iridotomy are influenced by various geometrical and fluid mechanical factors, the most relevant of which are the size of the hole and the length and height of the iris-lens channel. For certain iridotomy diameters, we find that the jet velocity through the iridotomy might be large enough to cause possible corneal damage.

Evaluation of choroidal tumors with optical coherence tomography: enhanced depth imaging and OCT-angiography features.

AimTo describe the vascular features of choroidal tumors using enhanced depth imaging (EDI), optical coherence tomography (OCT), and OCT-angiography.MethodsIn this prospective study, we evaluated 116 Caucasian patients with choroidal tumors (60 eyes with choroidal nevi, 40 with choroidal melanoma, 6 with choroidal hemangioma, 2 with optic disc melanocytoma, 6 with choroidal osteoma, and 2 with retinal metastases). Patients underwent a complete ophthalmic examination including bulbar echography, EDI-OCT, OCT-angiography, and multicolor imaging. Sixteen patients also underwent fluorescein and indocyanine angiography.ResultsThe left eye was more involved than the right eye. The mean tumor thickness was 1.23±0.17 mm in the 60 eyes with choroidal nevi; 2.75±0.83 mm in the 40 eyes with choroidal melanoma; 3.28±0.78 mm in the 6 eyes with retinal angioma; 2.02±0.001 mm in the 2 eyes with optic disc melanocytoma; 2.40±0.31 mm in the 6 eyes with choroidal osteoma; and last, 3.49±0.001 mm in the 2 eyes with retinal metastases. OCT-angiography showed: (i) a lack of blood flow in the outer retinal layer (ORL) and a normal choroid capillary layer in choroidal nevi and optic disc melanocytomas; (ii) a lack of blood flow in the ORL of choroidal metastases; and (iii) a dense irregular vascular network in the ORL and choroid capillary layers of choroidal melanomas, choroidal hemangiomas, and choroidal osteomas.ConclusionsOCT-angiography is a noninvasive reliable method with which to evaluate the vascularization of small choroidal tumors and may improve the diagnosis of these tumors.

Reduced-fluence verteporfin photodynamic therapy plus ranibizumab for choroidal neovascularization in pathologic myopia.

BACKGROUND: To demonstrate the efficacy of intravitreal ranibizumab (IVR) in combination with reduced-fluence photodynamic therapy (RF-PDT) in patients with choroidal neovascularization (CNV) secondary to pathologic myopia. METHODS: Sixty patients affected by myopic CNV (mCNV) were randomized to receive either ranibizumab 0.5 mg monotherapy (RM; n = 20), standard fluence PDT (SF-PDT, n = 20) or RF-PDT combination therapy (n = 20). Subsequently, IVR was injected as needed. All patients were evaluated for 48 weeks. RESULTS: Mean BCVA change at 48 weeks was + 0.2 and +15 letters with SF or RFPDT plus ranibizumab, respectively, compared with +16.8 letters with RM. At 48 weeks, mean central foveal thickness (CFT) decrease from baseline was 58 ± 15 µm, 91.4 ± 43.8 µm, and 85 ± 41.5 µm for the verteporfin SF, RF and RM groups, respectively. Macular sensitivity improvement was + 0.4 db, + 1.9 dB and + 2.7 dB for the verteporfin SF, RF and RM groups, respectively. CONCLUSIONS: Ranibizumab monotherapy or combined with RF-PDT improved BCVA and macular sensitivity in patients affected by mCNV, whereas CFT results were reduced. SF-PDT combination regimen mostly stabilized vision at 48 weeks. Among all groups, the RF-PDT seemed to reduce the number of ranibizumab retreatments.

Preclinical studies on new proteins as carrier for glycoconjugate vaccines.

Glycoconjugate vaccines are made of carbohydrate antigens covalently bound to a carrier protein to enhance their immunogenicity. Among the different carrier proteins tested in preclinical and clinical studies, five have been used so far for licensed vaccines: Diphtheria and Tetanus toxoids, the non-toxic mutant of diphtheria toxin CRM197, the outer membrane protein complex of Neisseria meningitidis serogroup B and the Protein D derived from non-typeable Haemophilus influenzae. Availability of novel carriers might help to overcome immune interference in multi-valent vaccines containing several polysaccharide-conjugate antigens, and also to develop vaccines which target both protein as well saccharide epitopes of the same pathogen. Accordingly we have conducted a study to identify new potential carrier proteins. Twenty-eight proteins, derived from different bacteria, were conjugated to the model polysaccharide Laminarin and tested in mice for their ability in inducing antibodies against the carbohydrate antigen and eight of them were subsequently tested as carrier for serogroup meningococcal C oligosaccharides. Four out of these eight were able to elicit in mice satisfactory anti meningococcal serogroup C titers. Based on immunological evaluation, the Streptococcus pneumoniae protein spr96/2021 was successfully evaluated as carrier for serogroups A, C, W, Y and X meningococcal capsular saccharides.

Carrier priming effect of CRM197 is related to an enhanced B and T cell activation in meningococcal serogroup A conjugate vaccination. Immunological comparison between CRM197 and diphtheria toxoid.

Glycoconjugate vaccines are composed of capsular polysaccharides (CPSs) of a pathogenic bacteria covalently linked to carrier proteins. Pre-exposure to the carrier is known to influence the efficacy of the glycoconjugate, by inducing enhanced or suppressed anti-CPS response. Following our previous work on the immunogenicity of diphtheria toxin mutant CRM197 and formaldehyde-treated diphtheria toxoid (DT) as carriers for meningococcal A (MenA) conjugates in mouse model, we further investigated the role of the carrier on the immunological response to glycoconjugate vaccines. We previously showed that high dosage DT priming could result in carrier-induced epitopic suppression (CIES), an event that did not occur for CRM197 priming, and we observed that anti-DT IgGs could cross-react with DT based conjugates in vitro. Here, we confirmed the cross-reactivity of anti-carrier IgGs with DT conjugates in vivo. Furthermore, we analyzed the splenocytes of animals primed with the carrier and subsequently immunized with the MenA conjugate. Pre-exposure to the carrier protein, both CRM197 and DT, resulted in increased carrier-specific plasma and memory B cell response. However, only for CRM197 priming an enhanced carbohydrate-specific plasma cell response was observed. Analysis of circulating IgGs confirmed these observations. Memory to the CPS resulted to be non-influenced by carrier priming. Analysis of T helper response showed an enhancement effect for CRM197 priming, while DT priming resulted in constrained T cell activation. Stimulation with CRM197, which does not require formaldehyde detoxification, of splenocytes from animal immunized with DT suggested that the formaldehyde treatment used to produce DT might be the cause of limited presentation of the antigen to the T cells. We concluded that the dominant carrier-specific B cell response in case of limited T cell recruitment might explain the previously observed CIES phenomenon in case of DT priming.

Evaluation of the non-toxic mutant of the diphtheria toxin K51E/E148K as carrier protein for meningococcal vaccines.

Diphtheria toxin mutant CRM197 is a common carrier protein for glycoconjugate vaccines, which has been proven an effective protein vector for, among others, meningococcal carbohydrates. The wide-range use of this protein in massive vaccine production requires constant increase of production yields and adaptability to an ever-growing market. Here we compare CRM197 with the alternative diphtheria non-toxic variant DT-K51E/E148K, an inactive mutant that can be produced in the periplasm of Escherichia coli. Biophysical characterization of DT-K51E/E148K suggested high similarity with CRM197, with main differences in their alpha-helical content, and a suitable purity for conjugation and vaccine preparation. Meningococcal serogroup A (MenA) glycoconjugates were synthesized using CRM197 and DT-K51E/E148K as carrier proteins, obtaining the same conjugation yields and comparable biophysical profiles. Mice were then immunized with these CRM197 and DT-K51E/E148K conjugates, and essentially identical immunogenic and protective effects were observed. Overall, our data indicate that DT-K51E/E148K is a readily produced protein that now allows the added flexibility of E. coli production in vaccine development and that can be effectively used as protein carrier for a meningococcal conjugate vaccine.

Anatomical and functional retinal changes in multiple sclerosis.

AIMS: The aims of this study was to report anatomical changes of the ganglion cell complex (GCC), retinal nerve fiber layer (RNFL) thickness, and macular volume in patients with multiple sclerosis (MS). We also investigated the correlation between anatomical and functional changes in terms of visual acuity and macular sensitivity investigated and visual fields. METHODS: Prospective comparative study included 105 eyes of 53 consecutive patients. The patients were divided into two groups: group A included 56 eyes of 28 patients with diagnosis of MS; group B involved 49 eyes of 25 healthy patients. The examination included Goldmann tonometry, biomicroscopic and fundus oculi examination, retinography, GCC examination, circumpapillary RNFL (cpRNFL), and macular volume. The functional test included measurement of best-corrected visual acuity (BCVA), visual field, and MP. RESULTS: MS group showed a significant reduced GCC, cpRNFL, macular volume, BCVA, visual field, and macular sensitivity compared with the control group (P<0.001). This reduction was more representative (P<0.001) in patients with MS complicated by optic neuritis (ON). We found in the MS group a strong correlation between GCC thickness and macular volume (r(2)=0.59, P<0.001) and also between GCC and RNFL thickness (r(2)=0.48, P<0.001). There was also a correlation between macular sensitivity and macular volume reduction (r(2)=0.25, P<0.001) and also between RNFL and macular volume (r(2)=0.43, P<0.001). CONCLUSIONS: The significant statistical evidence and the strong correlation between anatomical and functional parameters support the use of OCT and MP in the evaluation, treatment, and follow-up of patients diagnosed with MS.

Diabetic Retinopathy: Vascular and Inflammatory Disease.

Diabetic retinopathy (DR) is the leading cause of visual impairment in the working-age population of the Western world. The pathogenesis of DR is complex and several vascular, inflammatory, and neuronal mechanisms are involved. Inflammation mediates structural and molecular alterations associated with DR. However, the molecular mechanisms underlying the inflammatory pathways associated with DR are not completely characterized. Previous studies indicate that tissue hypoxia and dysregulation of immune responses associated with diabetes mellitus can induce increased expression of numerous vitreous mediators responsible for DR development. Thus, analysis of vitreous humor obtained from diabetic patients has made it possible to identify some of the mediators (cytokines, chemokines, and other factors) responsible for DR pathogenesis. Further studies are needed to better understand the relationship between inflammation and DR. Herein the main vitreous-related factors triggering the occurrence of retinal complication in diabetes are highlighted.

Carrier priming with CRM 197 or diphtheria toxoid has a different impact on the immunogenicity of the respective glycoconjugates: biophysical and immunochemical interpretation.

Glycoconjugate vaccines play an enormous role in preventing infectious diseases. The main carrier proteins used in commercial conjugate vaccines are the non-toxic mutant of diphtheria toxin (CRM197), diphtheria toxoid (DT) and tetanus toxoid (TT). Modern childhood routine vaccination schedules include the administration of several vaccines simultaneously or in close sequence, increasing the concern that the repeated exposure to conjugates based on these carrier proteins might interfere with the anti-polysaccharide response. Extending previous observations we show here that priming mice with CRM197 or DT does not suppress the response to the carbohydrate moiety of CRM197 meningococcal serogroup A (MenA) conjugates, while priming with DT can suppress the response to DT-MenA conjugates. To explain these findings we made use of biophysical and immunochemical techniques applied mainly to MenA conjugates. Differential scanning calorimetry and circular dichroism data revealed that the CRM197 structure was altered by the chemical conjugation, while DT and the formaldehyde-treated form of CRM197 were less impacted, depending on the degree of glycosylation. Investigating the binding and avidity properties of IgGs induced in mice by non-conjugated carriers, we found that CRM197 induced low levels of anti-carrier antibodies, with decreased avidity for its MenA conjugates and poor binding to DT and respective MenA conjugates. In contrast, DT induced high antibody titers able to bind with comparable avidity both the protein and its conjugates but showing very low avidity for CRM197 and related conjugates. The low intrinsic immunogenicity of CRM197 as compared to DT, the structural modifications induced by glycoconjugation and detoxification processes, resulting in conformational changes in CRM197 and DT epitopes with consequent alteration of the antibody recognition and avidity, might explain the different behavior of CRM197 and DT in a carrier priming context.

Serum and intraocular concentrations of erythropoietin and vascular endothelial growth factor in patients with type 2 diabetes and proliferative retinopathy.

AIM: This study compared systemic and intraocular concentrations of erythropoietin (EPO) and vascular endothelial growth factor (VEGF) in patients with type 2 diabetes (T2D) and proliferative diabetic retinopathy (PDR) with levels in patients without diabetes, and looked for possible correlations between the concentrations found and other variables analyzed. METHODS: Concentrations of EPO and VEGF were measured in the aqueous and vitreous humours and serum of patients undergoing vitrectomy for PDR (33 patients) or for macular holes or puckers (20 control patients). EPO was assayed by radioimmunoassay, with a lower limit of detection (LOD) of 1.0 mIU/mL. VEGF was assayed using enzyme-linked immunosorbent assay (ELISA), with a lower LOD of 10.0 pg/mL. RESULTS: EPO concentrations in serum did not differ significantly between the two groups, whereas EPO in vitreous and aqueous were higher in diabetic than in non-diabetic patients. VEGF in serum was lower in diabetic patients than in non-diabetics; conversely, VEGF concentrations in vitreous were significantly higher in diabetic patients. A direct correlation was found between vitreous and aqueous EPO concentrations, and between vitreous EPO and blood glucose concentrations. A significant, negative correlation between vitreous EPO concentration and age was also recorded. CONCLUSION: High EPO concentrations in the vitreous of patients with PDR and its correlation with blood glucose suggest that EPO could play a role in the pathogenesis of PDR. All possible factors affecting serum and ocular concentrations of EPO and VEGF should be determined to identify compounds able to prevent and control this serious microvascular complication of diabetes.

Neurotrophic keratitis.

Neurotrophic keratitis (NK) is a rare degenerative corneal disease that occurs as a result of partial or total impairment of trigeminal innervations, leading to a reduction (hypoesthesia) in or loss (anaesthesia) of corneal sensitivity. The impairment of sensory innervation causes a reduction in the lacrimation reflex and the vitality, metabolism and mitosis of epithelial cells, with subsequent deficiency in epithelial repair, stromal and intracellular oedema, loss of microvilli, and abnormal development of the basal lamina. Several recent studies have proposed different therapies based on different aetiopathogenetic theories. The aim of the therapy is to treat aetiopathogenesis and, at the same time, promote corneal healing. In this paper, we report the aetiology, diagnosis, management, and medical and surgical treatment of NK, also indicating future treatments based on the most recent studies.

TNF-alpha levels in tears: a novel biomarker to assess the degree of diabetic retinopathy.

We assess the level of tumour necrosis factor alpha (TNF-alpha) in tear fluids and other serum parameters associated with diabetes in different degrees of diabetic retinopathy. We have performed a prospective, nonrandomized, observational study. Study population consisted of 16 healthy subjects (controls) and 32 type 2 diabetic patients: 16 affected by proliferative diabetic retinopathy (PDR) and 16 with nonproliferative retinopathy (NDPR, background/preproliferative). Body mass index, urinary albumin, blood glucose, HbA1c, and tear levels of TNF-alpha were measured in all subjects. The value of glycaemia, microalbuminurea, and Body mass index in diabetic retinopathy groups were higher than those in control group (P < 0.05). Glycemia in NPDR: 6.6 mmol/L (range: 5.8-6.3); in PDR: 6.7 mmol/L (range: 6.1-7.2); in control: 5.7 mmol/L (range: 4.9-6.1); microalbuminurea in NPDR: 10.6 mg/L (range: 5.6-20); in PDR: 25.2 mg/L (range: 17-40); in control: 5.3 mg/L (range: 2.6-10); Body mass index in NPDR: 26 Kg/m(2) (range: 20.3-40); in PDR: 28 Kg/m(2) (range 20.3-52); in control: 21 Kg/m(2) (range 19-26). The TNF-alpha concentrations in tears increase with the severity of pathology and were lower in control group than in diabetic subjects. In the end, the level of TNF-alpha is highly correlated with severity of diabetic retinopathy and with nephropathy. Tear fluid collection may be a useful noninvasive method for the detection of proliferative diabetic retinopathy.

Intravitreal infliximab for choroidal neovascularization in patients refractory to conventional treatments.

The aim of the study is to evaluate the effectiveness and safety of intravitreal infliximab in the course of compassionate use in patients affected by choroidal neovascularization. This prospective interventional case series includes four eligible patients, affected by exudative age-related macular degeneration (2/4), retinal angiomatous proliferation (1/4) and central retinal vein occlusion (1/4), who were refractory to conventional treatments. The patients received a single intravitreal injection of 0.05 ml of reconstituted infliximab solution (20mg/ml). The main outcomes measure were changes in best-corrected visual acuity and central retinal thickness. Patients were evaluated at baseline, every week for the first month, then every two weeks, and on demand. Morphologic parameters improved after a single infliximab intravitreal injection. However, all patients developed acute uveitis in a period ranging from 4 to 7 weeks after treatment. Control of the intraocular inflammation was achieved with topical and systemic steroids in 3 patients, whereas in one case pars plana vitrectomy was needed. A single intravitreal injection of infliximab does not seem to improve the natural history of CNV from different aetiologies. However, all patients in our series developed a serious inflammatory response that required surgical management in one case. The intravitreal administration of infliximab is hence not safe and not recommended in clinical practice.

Meningococcal X polysaccharide quantification by high-performance anion-exchange chromatography using synthetic N-acetylglucosamine-4-phosphate as standard.

A method for meningococcal X (MenX) polysaccharide quantification by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) is described. The polysaccharide is hydrolyzed by strong acidic treatment, and the peak of glucosamine-4-phosphate (4P-GlcN) is detected and measured after chromatography. In the selected conditions of hydrolysis, 4P-GlcN is the prevalent species formed, with GlcN detected for less than 5% in moles. As standard for the analysis, the monomeric unit of MenX polysaccharide, N-acetylglucosamine-4-phosphate (4P-GlcNAc), was used. This method for MenX quantification is highly selective and sensitive, and it constitutes an important analytical tool for the development of a conjugate vaccine against MenX.

Comparison of CRM197, diphtheria toxoid and tetanus toxoid as protein carriers for meningococcal glycoconjugate vaccines.

Glycoconjugate vaccines are among the most effective and safest vaccines ever developed. Diphtheria toxoid (DT), tetanus toxoid (TT) and CRM197 have been mostly used as protein carriers in licensed vaccines. We evaluated the immunogenicity of serogroup A, C, W-135 and Y meningococcal oligosaccharides conjugated to CRM197, DT and TT in naïve mice. The three carriers were equally efficient in inducing an immune response against the carbohydrate moiety in immunologically naïve mice. The effect of previous exposure to different dosages of the carrier protein on the anti-carbohydrate response was studied using serogroup A meningococcal (MenA) saccharide conjugates as a model. CRM197 showed a strong propensity to positively prime the anti-carbohydrate response elicited by its conjugates or those with the antigenically related carrier DT. Conversely in any of the tested conditions TT priming did not result in enhancement of the anti-carbohydrate response elicited by the corresponding conjugates. Repeated exposure of mice to TT or to CRM197 before immunization with the respective MenA conjugates resulted in a drastic suppression of the anti-carbohydrate response in the case of TT conjugate and only in a slight reduction in the case of CRM197. The effect of carrier priming on the anti-MenA response of DT-based conjugates varied depending on their carbohydrate to protein ratio. These data may have implications for human vaccination since conjugate vaccines are widely used in individuals previously immunized with DT and TT carrier proteins.

Role of inflammation in endophthalmitis.

Inflammation originating from infection of the vitreous cavity is called endophthalmitis. Attention has been focused on the epidemiologic, microbiologic reports, and treatment options; unfortunately, the role of the host immune reaction in the visual function damage is still not well understood. Endophthalmitis occurs most frequently after cataract surgery. In this paper we review the published literature regarding inflammatory mediators and apoptosis during the course of endophthalmitis. Toll-like receptors, cytokines, high-mobility group box 1 proteins, aB-crystallin and apoptosis have been studied during clinical and experimental cases of endophthalmitis. Further understanding of the host-immune reaction to vitreous infection is essential for the development of new therapies. The use of intravitreal antibiotics and corticosteroids, vitrectomy and systemic antibiotics for the preservation of visual function is still discouraging.

Relative stability of meningococcal serogroup A and X polysaccharides.

Prior to the introduction of the MenAfriVac™ serogroup A glycoconjugate vaccine in September 2010, serogroup A was the major epidemic disease-causing meningococcal serogroup in the African meningitis belt. However, recently serogroup X meningococcal (MenX) disease has received increased attention because of outbreaks recorded in this region, with increased endemic levels of MenX disease over the past 2 years. Whereas polysaccharide-protein conjugate vaccines against meningococcal serogroups A, C, W and Y (MenA, MenC, MenW, MenY) are on the market, a vaccine able to protect against MenX has never been achieved. The structure of serogroup A, C, W and Y meningococcal polysaccharides has been already fully elucidated by NMR. MenX capsular polysaccharide (MenX CPS) structure is also documented but fewer characterization data have been published. We have applied here (1)H NMR, (31)P NMR and HPLC to evaluate the stability of MenX CPS in aqueous solution as compared to MenA capsular polysaccharide (MenA CPS). The stability study demonstrated that MenA CPS is more susceptible to hydrolytic degradation than MenX CPS. The different stereochemistry of the N-acetyl group at position C(2) of mannosamine (MenA CPS) and glucosamine (MenX CPS) respectively might play a fundamental role in this susceptibility to polysaccharide chain degradation. The satisfactory stability of MenX CPS predicts the possibility that a stable fully-liquid MenX polysaccharide or glycoconjugate vaccine could be developed.