Imaging techniques for posterior uveitis

Six-month outcomes of infliximab and tocilizumab therapy in non-infectious retinal vasculitis

PURPOSE

To evaluate the efficacy of infliximab (IFX, 5-10 mg/kg) (Group 1) and tocilizumab (TCZ, 4-8 mg/kg) (Group 2) infusions in non-infectious retinal vasculitis (RV) using Angiographic Scoring for the Uveitis Working Group fluorescein angiography (FA) scoring system.

METHODS

Records of 14 patients (24 eyes) in Group 1 and 8 patients (11 eyes) in Group 2 were retrospectively evaluated to assess visual acuity (VA), anterior chamber cell and flare, vitreous haze, central subfield thickness (CST), and FA scoring at baseline and 6 months of follow-up. The measurements were employed to grade in each group.

RESULTS

In Group 1 and 2, respectively, there was no underlying disease in 9 (60%) and 3 (42.9%) patients. Three (42.9%) patients in Group 2 had juvenile idiopathic arthritis (JIA) as the most common identified cause. Mean improvement in VA (log MAR) and CST were 0.04 ± 0.14 and 40.3 ± 78.5 µm in Group 1; 0.04 ± 0.09 and 47.3 ± 82.3 µm in Group 2, respectively. Mean FA scores were significantly reduced from 12.4 ± 5.2 and 11.6 ± 4.4 at baseline to 6.4 ± 5.0 and 5.8 ± 3.9 at 6-month in Group 1 and 2, respectively. In Group 2, 9 eyes of 6 patients (75%) had the history of IFX use prior to TCZ initiation. There was no significant safety concern requiring treatment discontinuation during the follow-up in either group.

CONCLUSION

IFX and TCZ infusions showed statistically significant improvement of non-infectious RV as shown by ASUWOG FA Scoring System. TCZ, as well as IFX, appeared to be effective treatment options for non-infectious RV.

X-Linked Retinoschisis Masquerading Uveitis

X-linked retinoschisis (XLRS) shows features also seen in patients with uveitis and is recognized as an uveitis masquerade syndrome. This retrospective study aimed to describe characteristics of XLRS patients with an initial uveitis diagnosis and to contrast these to patients with an initial XLRS diagnosis. Patients referred to a uveitis clinic, which turned out to have XLRS (n = 4), and patients referred to a clinic for inherited retinal diseases (n = 18) were included. All patients underwent comprehensive ophthalmic examinations, including retinal imaging with fundus photography, ultra-widefield fundus imaging, and optical coherence tomography (OCT). In patients with an initial diagnosis of uveitis, a macular cystoid schisis was always interpreted as an inflammatory macular edema; vitreous hemorrhages were commonly interpreted as intraocular inflammation. Patients with an initial diagnosis of XLRS rarely (2/18; p = 0.02) showed vitreous hemorrhages. No additional demographic, anamnestic, and anatomical differences were found. An increased awareness of XLRS as a uveitis masquerade syndrome may facilitate early diagnosis and may prevent unnecessary therapies.

Endothelial Toll-like receptor 4 is required for microglia activation in the murine retina after systemic lipopolysaccharide exposure

BACKGROUND

Clustering of microglia around the vasculature has been reported in the retina and the brain after systemic administration of lipopolysaccharides (LPS) in mice. LPS acts via activation of Toll-like receptor 4 (TRL4), which is expressed in several cell types including microglia, monocytes and vascular endothelial cells. The purpose of this study was to investigate the effect of systemic LPS in the pigmented mouse retina and the involvement of endothelial TLR4 in LPS-induced retinal microglia activation.

METHODS

C57BL/6J, conditional knockout mice that lack Tlr4 expression selectively on endothelial cells (Tek^Cre-posTlr4^loxP/loxP) and Tek^Cre-negTlr4^loxP/loxP mice were used. The mice were injected with 1 mg/kg LPS via the tail vein once per day for a total of 4 days. Prior to initiation of LPS injections and approximately 5 h after the last injection, in vivo imaging using fluorescein angiography and spectral-domain optical coherence tomography was performed. Immunohistochemistry, flow cytometry, electroretinography and transmission electron microscopy were utilized to investigate the role of endothelial TLR4 in LPS-induced microglia activation and retinal function.

RESULTS

Activation of microglia, infiltration of monocyte-derived macrophages, impaired ribbon synapse organization and retinal dysfunction were observed after the LPS exposure in C57BL/6J and Tek^Cre-negTlr4^loxP/loxP mice. None of these effects were observed in the retinas of conditional Tlr4 knockout mice after the LPS challenge.

CONCLUSIONS

The findings of the present study suggest that systemic LPS exposure can have detrimental effects in the healthy retina and that TLR4 expressed on endothelial cells is essential for retinal microglia activation and retinal dysfunction upon systemic LPS challenge. This important finding provides new insights into the role of microglia-endothelial cell interaction in inflammatory retinal disease.

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE)

Background

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is a rare inflammatory eye disease, affecting the inner choroid and the outer retina. Recent advances in multimodal imaging have been important in the understanding of the pathophysiology of the disease, allowing a better characterization of the morphology of this condition.

Methods

Narrative review.

Results

In this review, a comprehensive overview of clinical features, imaging findings, treatment management, and long-term outcomes of patients with APMPPE will be provided.

Conclusions

Although APMPPE was originally believed to be a self-limited condition with a good prognosis, the disease can be recurrent and result in significant loss of vision function. Fundus imaging plays an important role in the diagnosis and management of the disease, allowing to evaluate response to treatment and onset of complications.

Structural Endpoints and Outcome Measures in Uveitis

Most uveitis entities are rare diseases but, taken together, are responsible for 5-10% of worldwide visual impairment which largely affects persons of working age. As with many rare diseases, there is a lack of high-level evidence regarding its clinical management, partly due to a dearth of reliable and objective quantitative endpoints for clinical trials. This review provides an overview of available structural outcome measures for uveitis disease activity and damage in an anatomical order from the anterior to the posterior segment of the eye. While there is a multitude of available structural outcome measures, not all might qualify as endpoints for clinical uveitis trials, and thorough testing of applicability is warranted. Furthermore, a consensus on endpoint definition, standardization, and "core outcomes" is required. As stipulated by regulatory agencies, endpoints should be precisely defined, clinically important, internally consistent, reliable, responsive to treatment, and relevant for the respective subtype of uveitis. Out of all modalities used for assessment of the reviewed structural outcome measures, optical coherence tomography, color fundus photography, fundus autofluorescence, and fluorescein/indocyanine green angiography represent current "core modalities" for reliable and objective quantification of uveitis outcome measures, based on their practical availability and the evidence provided so far.

Widefield Fundus Fluorescein Angiography Features of Uveitis Associated with Juvenile Idiopathic Arthritis

PURPOSE

To evaluate the wide-field fundus fluorescein angiography (WFA) characteristics of uveitis associated with juvenile idiopathic arthritis (JIA-uveitis).

METHODS

Retrospective review of records. WFA with Spectralis (Heidelberg) of JIA-uveitis patients were analyzed using the scoring system by Angiography Scoring for Uveitis Nomenclature.

RESULTS

Thirty-seven eyes of 20 patients were studied. A total score of at least 1 was noted in 27 eyes (72.97%). WFA features included optic disc hyperfluorescence (51.35%), macular leakage (27.03%), retinal vascular staining/leakage at posterior pole (27.03%) and peripheral retina (64.86%), capillary leakage at the posterior pole (37.84%), and peripheral retina (59.46%). A decision to change the management plan was made in 8 of 9 patients with bilateral quiet anterior chambers after WFA results.

CONCLUSION

More than 70% of JIA-uveitis eyes showed some WFA-evidence of posterior segment inflammation, which changed the course of therapy for a major proportion of patients with no clinically active anterior chamber inflammation.

Fluorescein Angiography Scoring System Using Ultra-Wide-Field Fluorescein Angiography Versus Standard Fluorescein Angiography in Patients with Sarcoid Uveitis

Purpose: To compare standard fluorescein angiography (FA) and ultra-wide-field (UWF) FA in evaluating sarcoid uveitis activity using the scoring system adopted by the Angiography Scoring for Uveitis Working Group (ASUWG).Methods: Standard and UWF FA images of 36 eyes with sarcoid uveitis were acquired on the same day. Three graders independently graded 72 FA images using the ASUWG scoring system. We evaluated inter-observer variability using the intra-class correlation coefficient (ICC) and compared scores of each angiographic sign.Results: The ICC was 0.77 for standard FA and 0.87 for UWF FA, with respective total scores of 12.0 and 14.6. UWF FA had higher scores than standard FA for optic disc hyperfluorescence, posterior retinal vascular staining and/or leakage, and peripheral capillary leakage.Conclusions: The scores for UWF FA had a higher ICC than those for standard FA in evaluating sarcoid uveitis. Peripheral capillary leakage scores were particularly high for UWF FA.

Immediate Reactions to Fluorescein and Indocyanine Green in Retinal Angiography: Review of Literature and Proposal for Patient's Evaluation

Introduction

Contrast rapid sequence angiography with fluorescein or indocyanine green (ICG) is a diagnostic procedure commonly used in ophthalmology. Adverse reactions to fluorescein and ICG are rare and may be classified as toxic, of hypersensitivity and non-specific. The evaluation and management of a patient with an adverse reaction is a challenge for the majority of ophthalmologists, as is the assessment of risk factors that may contraindicate the procedure.

Purpose

We aim to review the concepts underlying adverse reactions to fluorescein and ICG, especially those of hypersensitivity, and present a proposal or the evaluation of the patients in need to perform retinal angiography and for the treatment of immediate reactions to fluorescein and ICG.

Methods

The available literature was examined using PubMed-Medline, and using the MeSH terms "fluorescein", "Indocyanine green", "ophthalmic dyes", "retinal angiography", "adverse reactions", and "allergic reaction".

Conclusion

This review may help ophthalmologists to identify patients with higher risk of a hypersensitivity reaction and give them tools to recognize patients with suspected hypersensitivity that may benefit from an allergy study.

Imaging techniques for minimally invasive thoracic surgery-Korea University Guro Hospital experiences

In this paper, we described our clinical experiences with respect to image-guided thoracic surgery, including procedures involving percutaneous injection of fluorescent dye, radiotracers, and hook wires, guided by preoperative computed tomography (CT); and transbronchial injection of fluorescent dye by using electromagnetic navigational bronchoscope technology. Our recent experience with the intravenous systemic injection of fluorescent dye for the intraoperative detection of pulmonary lesions and intersegmental planes are also described in this review.

Contribution of Dual Fluorescein and Indocyanine Green Angiography to the Appraisal of Presumed Tuberculous Chorioretinitis in a Non-endemic Area

PURPOSE

To assess the respective involvement of retina versus choroid in presumed ocular tuberculosis (POT) in a non-endemic area using dual fluorescein (FA) and indocyanine green angiography (ICGA).

METHODS

We retrospectively analyzed cases diagnosed with POT at the Centre for Ophthalmic Specialized Care, Lausanne, Switzerland. Angiography signs were quantified using an established dual FA and ICGA scoring system for uveitis.

RESULTS

Out of 1739 uveitis patients visited from 1995 to 2014, 53 (3%) were diagnosed with POT; of whom 28 patients (54 eyes) had sufficient data available to be included in this study. Of 54 affected eyes, 39 showed predominant choroidal involvement, 14 showed predominant retinal involvement and one had equal retinal and choroidal scores. Mean angiographic score was 6.97 ± 5.08 for the retina versus 13.48 ± 7.06 for the choroid (P < 0.0001). For patients with sufficient angiographic follow-up after combined anti-tuberculous and inflammation suppressive therapy, mean FA and ICGA scores decreased from 6.97 ± 5.08 to 3.63 ± 3.14 (P = 0.004), and 13.48 ± 7.06 to 7.47 ± 5.58 (P < 0.0001), respectively.

CONCLUSION

These results represent the first report of the respective contributions of retinal and choroidal involvement in POT. Choroidal involvement was more common, for which ICGA is the preferred examination. In cases of compatible uveitis with positive results of an interferon-gamma release assay, particularly in a region that is non-endemic for TB, dual FA and ICGA should be performed to help establish the diagnosis of ocular tuberculosis and improve follow-up.

Indocyanine green fluorescence angiography for free flap monitoring: A pilot study

OBJECTIVE

We evaluated the feasibility and the tolerance of repeated fluorescent indocyanine green angiography in free flap monitoring, and determined the intraoperative predictive values of flap vitality.

BACKGROUND

The free flap failure rate has been significantly reduced, but free flap loss still occurs and remains a costly disaster. Repeated clinical examinations are commonly used for flap monitoring, but they can be unreliable because of their subjectivity. Laser-induced fluorescence of indocyanine green is a new method for assessing tissue perfusion.

METHODS

20 patients undergoing microsurgical reconstruction were monitored by indocyanine green fluorescence angiography, intraoperatively, and during 4 days after surgery, with 18 injections. Monitoring was made by clinical examination, and then compared to angiographic findings.

RESULTS

The vascular complication rate was 15% (3/20) with 2 cases of venous thrombosis and one case of partial necrosis of the flap skin paddle. Both cases of venous thrombosis were salvaged by secondary surgery. There was no total flap loss. ICG angiography allowed detecting each intra and postoperative complication, earlier than clinical examination. The mean per-operative intensity of fluorescence was significantly lower in flaps with vascular complications (23.8 GL/ms; p = 0.008). The postoperative slope (p = 0.02) and amplitude (p = 0.03) of the fluorescent signal were both significantly lower than for uncomplicated flaps, before surgical revision. These 2 parameters came back to normal values after secondary surgery. There was no adverse effect of ICG despite the repeated injections.

CONCLUSION

ICG angiography is a feasible and safe technique for the detection of free flap vascular complications.

Correlation between Fluorescein Angiographic Findings and Visual Acuity in Behçet Retinal Vasculitis

PURPOSE

To identify significant fluorescein angiographic (FA) characteristics associated with visual acuity (VA) in Behçet retinal vasculitis.

MATERIALS AND METHODS

Retrospective review of 86 eyes of 48 patients (age: 35.6±10.2 years) with Behçet retinal vasculitis were performed. VA and FA findings as well as correlation between them were assessed.

RESULTS

The mean initial VA of eyes with posterior pole-involved vasculitis (63 eyes; 73.3%) was significantly worse than that of those with peripheral vasculitis (23 eye; 26.7%) (logarithm of the minimum angle of resolution VA: 0.554±0.572 vs. 0.078±0.148; p<0.0001). Subgroup analysis revealed a more severe and diffuse pattern of vascular leakage in posterior pole-involved vasculitis compared to peripheral vasculitis (p<0.0001). Retinal vascular leakage (β=0.345; p<0.0001), optic disc hyperfluorescence (β=0.147; p=0.032), and macular leakage (β=0.107; p=0.047) were significantly associated with worse initial VA. During the follow up (mean: 33.3±17.9 months), the change of leakage showed no significant correlation with change of VA in posterior pole-involved vasculitis (τ=0.199, p=0.092).

CONCLUSION

Posterior pole involvement, the degree of retinal vascular leakage, optic disc hyperfluorescence, and macular leakage are significantly associated with VA in Behçet retinal vasculitis.

Retinal imaging in uveitis

Ancillary investigations are the backbone of uveitis workup for posterior segment inflammations. They help in establishing the differential diagnosis and making certain diagnosis by ruling out certain pathologies and are a useful aid in monitoring response to therapy during follow-up. These investigations include fundus photography including ultra wide field angiography, fundus autofluorescence imaging, fluorescein angiography, optical coherence tomography and multimodal imaging. This review aims to be an overview describing the role of these retinal investigations for posterior uveitis.

Ancillary investigations in uveitis

Ancillary investigations are the backbone of uveitis work-up both for anterior and posterior segment diseases. They help in making the diagnosis, ruling out certain differential diagnosis and monitoring inflammation during the follow-up. This review aims to be an overview describing the role of commonly used investigations for uveitis.

Near infrared fluorescence imaging after intravenous indocyanine green: initial clinical experience with open partial nephrectomy for renal cortical tumors

OBJECTIVE

To evaluate the safety of near infrared fluorescence (NIRF) of intravenously injected indocyanine green (ICG) during open partial nephrectomy, and to demonstrate the feasibility of this technology to identify the renal vasculature and distinguish renal cortical tumors from normal parenchyma.

METHODS

Patients undergoing open partial nephrectomy provided written informed consent for inclusion in this institutional review board-approved study. Perirenal fat was removed to allow visualization of the renal parenchyma and lesions to be excised. The patients received intravenous injections of ICG, and NIRF imaging was performed using the SPY system. Intraoperative NIRF video images were evaluated for differentiation of tumor from normal parenchyma and for renal vasculature identification.

RESULTS

A total of 15 patients underwent 16 open partial nephrectomies. The mean cold ischemia time was 26.6 minutes (range 20-33). All 14 malignant lesions were afluorescent or hypofluorescent compared with the surrounding normal renal parenchyma. NIRF imaging of intravenously injected ICG clearly identified the renal hilar vessels and guided selective arterial clamping in 3 patients. No adverse reactions to ICG were noted, and all surgical margins were negative on final pathologic examination.

CONCLUSION

The intravenous use of ICG combined with NIRF is safe during open renal surgery. This technology allows the surgeon to distinguish renal cortical tumors from normal tissue and highlights the renal vasculature, with the potential to maximize oncologic control and nephron sparing during open partial nephrectomy. Additional study is needed to determine whether this imaging technique will help improve the outcomes during open partial nephrectomy.

Near infrared fluorescence imaging with robotic assisted laparoscopic partial nephrectomy: initial clinical experience for renal cortical tumors

PURPOSE

We evaluated the utility of near infrared fluorescence of intravenously injected indocyanine green in performing robotic assisted laparoscopic partial nephrectomy. In addition, we evaluated the initial performance of a novel near infrared fluorescence imaging system integrated into the da Vinci® Si Surgical System during robotic assisted laparoscopic nephrectomy.

MATERIALS AND METHODS

Fluorescence imaging for the da Vinci Si Surgical System was used for all cases. Indocyanine green was injected before near infrared imaging. Immediate imaging assessed the renal vasculature while delayed imaging differentiated renal cortical tumors from normal parenchyma. The intraoperative performance of near infrared fluorescence of intravenous indocyanine green was evaluated for tumor appearance relative to surrounding renal parenchyma as well as identification of the renal vasculature.

RESULTS

A total of 11 patients underwent robotic assisted laparoscopic nephrectomy with 2 converted to robotic assisted laparoscopic radical nephrectomy. Indocyanine green injections were repeated up to a total of 5 times depending on the goal of visualization. Of the 11 patients 10 demonstrated malignancy on final pathology. Of the malignant tumors 7 were hypofluorescent and 3 were isofluorescent compared to the surrounding renal parenchyma. Near infrared fluorescence imaging delineated the vascular anatomy in all cases. All surgical margins were negative on final pathology.

CONCLUSIONS

Intraoperative imaging of indocyanine green with near infrared fluorescence is a safe and effective method to accurately identify the renal vasculature and to differentiate renal tumors from surrounding normal parenchyma. The capacity for multimodal imaging within the surgical console further facilitates this imaging. Further study is needed to determine if this technique will help improve outcomes of robotic assisted laparoscopic nephrectomy.

Functionalized cyclic RGD peptidomimetics: conjugable ligands for αvβ3 receptor imaging

The α(v)β(3) integrin is an adhesion molecule involved in physiological and pathological angiogenesis as well as in tumor invasion and metastasis, and therefore, there is a strong interest in developing novel agents interacting with this molecule. We report the synthesis and characterization of fluorescent α(v)β(3) integrin probes and their use to visualize integrin α(v)β(3) expression on human normal and cancer cells. The fluorescent probes we describe here may be of use for noninvasive imaging of α(V)β(3) integrin expression also in vivo.

Hepatic, ocular, and cutaneous sarcoidosis

Sarcoid affecting the skin, eye, or liver can be symptomatic of or cause significant morbidity. When disease is sever, alternative therapies may be needed.

A comparison of the emission efficiency of four common green fluorescence dyes after internalization into cancer cells

In vivo optical imaging to enhance the detection of cancer during endoscopy or surgery requires a targeted fluorescent probe with high emission efficiency and high signal-to-background ratio. One strategy to accurately detect cancers is to have the fluorophore internalize within the cancer cells permitting nonbound fluorophores to be washed away or absorbed. The choice of fluorophores for this task must be carefully considered. For depth of penetration, near-infrared probes are ordinarily preferred but suffer from relatively low quantum efficiency. Although green fluorescent protein has been widely used to image tumors on internal organs in mice, green fluorescent probes are better suited for imaging the superficial tissues because of the short penetration distance of green light in tissue and the highly efficient production of signal. While the fluorescence properties of green fluorophores are well-known in vitro, less attention has been paid to their fluorescence once they are internalized within cells. In this study, the emission efficiency after cellular internalization of four common green fluorophores conjugated to avidin (Av-fluorescein, Av-Oregon green, Av-BODIPY-FL, and Av-rhodamine green) were compared after each conjugate was incubated with SHIN3 ovarian cancer cells. Using the lectin binding receptor system, the avidin-fluorophore conjugates were endocytosed, and their fluorescence was evaluated with fluorescence microscopy and flow cytometry. While fluorescein demonstrated the highest signal outside the cell, among the four fluorophores, internalized Av-rhodamine green emitted the most light from SHIN3 ovarian cancer cells both in vitro and in vivo. The internalized Av-rhodamine green complex appeared to localize to the endoplasmic vesicles. Thus, among the four common green fluorescent dyes, rhodamine green is the brightest green fluorescence probe after cellular internalization. This information could have implications for the design of tumor-targeted fluorescent probes that rely on cellular internalization for cancer detection.

VLA-4 blockade suppresses endotoxin-induced uveitis: in vivo evidence for functional integrin up-regulation

Leukocyte adhesion to the vascular wall is a critical early step in the pathogenesis of inflammatory diseases and is mediated in part by the leukocyte integrin, VLA-4, which binds to endothelial vascular cell adhesion molecule (VCAM) -1. Here, we investigate VLA-4's role in endotoxin-induced uveitis (EIU). At various time points (6-48 h) after EIU induction, the severity of the inflammation was evaluated by quantifying cell and protein content in the aqueous fluid, firm leukocyte adhesion in the retinal vessels, and the number of extravasated leukocytes into the vitreous. Functional activation of VLA-4 in vivo was investigated in our previously introduced autoperfused micro flow chamber assay. Firm adhesion of EIU leukocytes to immobilized VCAM-1 under physiological blood flow conditions was significantly increased compared with normal controls (P<0.05), suggesting an important role for VLA-4 in EIU. VLA-4 blockade in vivo significantly suppressed all uveitis-related inflammatory parameters studied, decreasing the clinical score by 45% (P<0.01), protein content in the aqueous fluid by 21% (P<0.01), retinal leukostasis by 68% (P<0.01), and leukocyte accumulation in the vitreous by 75% (P<0.01). Our data provide novel evidence for functional up-regulation of VLA-4 during EIU and suggest VLA-4 blockade as a promising therapeutic strategy for treatment of acute inflammatory eye diseases.

In vivo spectral fluorescence imaging of submillimeter peritoneal cancer implants using a lectin-targeted optical agent

Intraperitoneal metastases commonly recur after surgery because small tumor foci escape detection within the complex anatomy of the peritoneal cavity and mesentery. Accurate localization of peritoneal implants during surgery could improve the resection of ovarian cancer and other malignancies, but few practical techniques to enhance detectability are currently available. Here, we describe a targeted molecular imaging method that employs fluorescently labeled avidin to detect submillimeter peritoneal implants of ovarian cancer in mice. After binding to surface lectins on the tumor, fluorescein-conjugated avidin enabled the spectral fluorescence imaging of disseminated peritoneal implants. High spatial resolution and high tumor-to-background ratio allowed the visualization of implants as small as 0.3 mm (with 100% sensitivity and specificity; n = 150) and the identification of even smaller lesions ex vivo. These results suggest that targeted molecular imaging with a fluorescence-labeled lectin-ligand system is a promising technique for the detection of disseminated submillimeter foci of cancer.