Ocular tolerability and efficacy of intravitreal and subconjunctival injections of sirolimus in patients with non-infectious uveitis: primary 6-month results of the SAVE Study

Equine uveitis: Outcome and adverse effects after one or two intravitreal low-dose gentamicin injections

BACKGROUND

Uveitis is common in horses, potentially turning chronic (persistent or recurrent) resulting in impaired vision or blindness. All mainstay therapeutics aims at controlling inflammation, but long-term or lifelong treatment is often needed with possibly severe side effects. Therefore, intravitreal injections with low-dose gentamicin (IVGI) have been used in attempt to give a long-lasting result with potentially less side effects.

OBJECTIVES

To retrospectively assess outcome and long-term complications following one or two low-dose IVGI in Swedish horses with chronic uveitis.

STUDY DESIGN

Retrospective case series.

METHODS

Medical records of horses diagnosed with uveitis examined at the Equine Clinic of the University Animal Hospital of Sweden between 2016 and 2021 were reviewed. Inclusion criteria were horses with a diagnosis of chronic uveitis that were treated with 4 mg IVGI. After injection, tapering doses of anti-inflammatory medications were administered. Due to persistence or recurrence of uveitis despite IVGI, some horses received a second injection. A positive outcome was defined as controlled uveitis, despite no or minimal anti-inflammatory medication.

RESULTS

32 eyes (29 horses) were included. Based on clinical evaluation, uveitis was classified as anterior (91%) or panuveitis (9%). 10 eyes were treated with IVGI twice. A positive outcome was observed in 13/32 eyes (41%). Inflammation in 9/32 eyes was controlled after the first, and in 4/10 eyes after the second IVGI treatment. Long-term complications included retinal degeneration in seven eyes, and mature cataracts in five eyes. Enucleations were performed in 14/32 eyes, due to lack of favourable response of IVGI, or due to complications, that is, glaucoma, corneal ulceration, and/or corneal mineralisation. One horse was euthanised due to painful bouts of inflammation in both eyes despite treatment.

MAIN LIMITATIONS

Small sample size, retrospective design with no control group, no histopathology performed, infrequent sampling for Leptospira and no standardised treatment protocol after the IVGI.

CONCLUSIONS

In this group of Swedish horses, predominantly diagnosed clinically with anterior uveitis, a positive outcome was observed in 41% of eyes following one or two low-dose IVGI. Retinal degeneration in the visual streak was observed in 22% of eyes, which is a higher proportion of this complication than previously described.

Tacrolimus Improves Therapeutic Efficacy of Umbilical Cord Blood-Derived Mesenchymal Stem Cells in Diabetic Retinopathy by Suppressing DRP1-Mediated Mitochondrial Fission

Diabetic retinopathy (DR) is a leading cause of blindness in diabetic patients. Umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) are emerging as a promising new drug for degenerative disease associated with diabetes. Recent studies have shown that high glucose-increased excessive calcium levels are a major risk factor for mitochondrial reactive oxygen species (mtROS) accumulation and apoptosis. This study aimed to investigate the role of high glucose-induced NFATC1 signaling in mitochondrial oxidative stress-stimulated apoptosis and the effect of tacrolimus on the therapeutic efficacy of subconjunctival transplantation of UCB-MSCs in a DR rat model. High glucose increased mtROS and cleaved caspase-9 expression in UCB-MSCs. High glucose conditions increased O-GlcNAcylated protein expression and nuclear translocation of NFATC1. Tacrolimus pretreatment recovered high glucose-induced mtROS levels and apoptosis. In the DR rat model, subconjunctival transplantation of tacrolimus-pretreated MSCs improved retinal vessel formation, retinal function, and uveitis. In high glucose conditions, tacrolimus pretreatment reduced protein and mRNA expression levels of DRP1 and inhibited mitochondrial fission. In conclusion, we demonstrated that high glucose-induced O-GlcNAcylation activates NFATC1 signaling, which is important for DRP1-mediated mitochondrial fission and mitochondrial apoptosis. Finally, we proposed NFATC1 suppression by tacrolimus as a promising therapeutic strategy to improve the therapeutic efficacy of UCB-MSC transplantation for DR treatment.

Preventive Effects of Exosome-Rich Conditioned Medium From Amniotic Membrane-Derived Mesenchymal Stem Cells for Diabetic Retinopathy in Rats

Purpose

Diabetic retinopathy (DR) is an important disease that causes vision loss in many diabetic patients. Stem cell therapy has been attempted for treatment of this disease; however, it has some limitations. This study aimed to evaluate the preventive efficacy of exosome-rich conditioned medium (ERCM) derived from amniotic membrane stem cells for DR in rats.

Methods

Twenty-eight 8-week-old male Sprague-Dawley rats were divided into three groups: group 1, normal control (Con) group; group 2, diabetes mellitus (DM) group; and group 3, DM with ERCM-treated (DM-ERCM) group. DM was induced by intraperitoneal injection of streptozotocin. The DM-ERCM group received ERCM containing 1.2 × 10⁹ exosomes into subconjunctival a total of four times every 2 weeks.

Results

On electroretinogram, the DM-ERCM group had significantly higher b-wave and flicker amplitudes than those in the DM group. In fundoscopy, retinal vascular attenuation was found in both the DM and DM-ERCM groups; however, was more severe in the DM group. On histology, the ganglion cell and nerve fiber layer rates of the total retinal layer significantly increased in the DM group compared with the Con group, whereas the DM-ERCM group showed no significant difference compared with the Con group. Cataracts progressed significantly more in the DM group than that in the DM-ERCM group and there was no uveitis in the DM-ERCM group.

Conclusions

Subconjunctival ERCM delayed the progression of DR and cataracts and significantly reduced the incidence of uveitis.

Translational Relevance

Our study shows the clinical potential of minimally invasive exosome-rich conditioned medium treatment to prevent diabetic retinopathy.

Utilisation of composite endpoint outcome to assess efficacy of tocilizumab for non-infectious uveitis in the STOP-Uveitis Study

BACKGROUND/AIMS

To use a composite endpoint scoring system in assessing efficacy of two doses of intravenous tocilizumab (TCZ), in eyes with non-infectious uveitis.

METHODS

Data from STOP-Uveitis Study (a phase 2 multicentre, randomised, interventional clinical trial), where monthly intravenous infusions of 4 mg/kg (Group 1) or 8 mg/kg (Group 2) TCZ until month 6 (M6) were administered, were used. Efficacy was ascertained by a composite endpoint scoring system consisting of: (1) visual acuity; (2) intraocular inflammation; (3) central retinal thickness; (4) posterior segment inflammation on fluorescein angiographic and (5) steroid taper. Each component of grading system was graded as ((+1) improvement, (-1) worsening or (0) no change) based on specific criteria. The clinical response was classified as positive (improvement in at least one parameter and worsening in none), negative (worsening of any parameter) or stable (neither improvement nor worsening of any parameter). The percentage achieving various clinical responses was compared between groups.

RESULTS

Thirty-seven patients were analysed. At M6, 31 (83.8%) subjects demonstrated a positive clinical response (Group 1=14 (77.8%) and Group 2=17 (89.5%)). Three (8.1%) subjects (all Group 1) met the criteria for treatment failure, whereas three (8.1%) subjects showed a stable clinical response (Group 1=1 and Group 2=2). The difference in clinical responses between study groups was not significant (p>0.05).

CONCLUSIONS

Both doses of intravenous TCZ were effective in either improving or maintaining stability in patients using the composite endpoint scoring system. A composite scoring system as used in this study may be a better measure to assess efficacy outcomes as compared with only vitreous haze or other single outcome measures.

Intravitreal immunotherapy in non-infectious uveitis: an update

INTRODUCTION

In the past several years, there have been numerous advances in pharmacotherapeutics for the management of uveitis and other ocular inflammatory diseases, including newer therapeutic agents and ocular drug delivery systems. One of the most attractive modes of drug delivery is the intravitreal route since it has proven to be safe and efficacious and prevents unwanted systemic adverse events related to the agent.

AREAS COVERED

In this review, intravitreal delivery of various pharmacotherapeutic agents for noninfectious uveitis has been described. An extensive review of the literature was performed using specific keywords on the PubMed database to identify clinical studies employing various pharmacotherapeutic agents with intravitreal drug delivery for noninfectious uveitis. The mode of action, safety, efficacy, and tolerability of these drugs have also been elucidated.

EXPERT OPINION

Several agents, including biologic response modifier agents, have been found to be safe and efficacious for various indications of uveitis, such as cystoid macular edema, active uveitis, and other conditions such as retinal vasculitis and vitreous haze. The use of intravitreal biological therapies, especially infliximab, has been fraught with potential safety signals such as photoreceptor toxicity. However, pharmacotherapeutic agents such as corticosteroids and anti-vascular endothelial growth factor agents are now widely used in the clinical management of uveitis and its complications.

Cellular Recycling Gone Wrong: The Role of Dysregulated Autophagy and Hyperactive mTORC1 in the Pathogenesis of Sarcoidosis

BACKGROUND AND AIMS

Autophagy is a highly regulated, complex intracellular recycling process that is vital to maintaining cellular homeostasis in response to diverse conditions and stressors. Despite the presence of robust regulatory pathways, the intricate and multi-step nature of autophagy creates opportunity for dysregulation. Errors in autophagy have been implicated in the development of a broad range of clinical pathologies including granulomatous disease. Specifically, activation of the mTORC1 pathway has been identified as a key negative regulator of autophagic flux, prompting the study of dysregulated mTORC1 signaling in the pathogenesis of sarcoidosis. Our review: We conducted a thorough search of the extant literature to identify the regulatory pathways of autophagy, and more specifically the implication of upregulated mTORC1 pathways in the pathogenesis of sarcoidosis. We review data showing spontaneous granuloma formation in animal models with upregulate mTORC1 signaling, human genetic studies showing mutation in autophagy genes in sarcoidosis patients, and clinical data showing that targeting autophagy regulatory molecules like mTORC1 may provide new therapeutic approaches for sarcoidosis.

CONCLUSIONS

Given the incomplete understanding of sarcoidosis pathogenesis and the toxicities of current treatments, a more complete understanding of sarcoidosis pathogenesis is crucial for the development of more effective and safer therapies. In this review, we propose a strong molecular pathway driving sarcoidosis pathogenesis at which autophagy is at the center. A more complete understanding of autophagy and its regulatory molecules, like mTORC1, may provide a window into new therapeutic approaches for sarcoidosis.

A review of patient-reported outcome measures used in uveitis

We review patient-reported outcome measures (PROMs) used to evaluate the quality of life (QoL) in uveitis and provide a quality assessment of the psychometric properties of the PROMs, making it easier to choose the best questionnaire for uveitis. Our review included 158 articles. A total of 98 PROMs were used to measure QoL in uveitis and the National Eye Institute Visual Function Questionnaire 25 (NEI VFQ -25) was the most frequently used PROM in these studies. There were 5 uveitis-specific PROMs, but they were meant for either birdshot choroidopathy or cytomegalovirus retinitis or paediatric uveitis. There are no PROMs developed explicitly for the more common, anterior uveitis, intermediate uveitis, panuveitis, and chronic uveitis. The uveitis-specific PROMs performed better in our quality assessment criteria compared to other PROMs. However, these PROMs were constructed using traditional classical test theory and have not been assessed using the modern family of psychometric assessment methods such as Rasch analysis. As new therapeutic modalities for uveitis such as the new biological agents and steroid implants, continue to evolve, a comprehensive PROM will be increasingly valued in clinical trial settings to compare the effects of treatments from the patient's perspective.

Pharmacokinetics of Sirolimus in a Novel Liposome Delivery System in Selected Ocular Tissues and Plasma Following a Single Subconjunctival Injection in Dutch Belted Rabbits

Purpose: To determine the pharmacokinetics of a proprietary liposomal sirolimus (LS) formulation in ocular tissues and plasma following a single subconjunctival (SCJ) injection in Dutch belted rabbits (DBR). Analytical methods for detection of LS in plasma, aqueous humor (AH), vitreous humor (VH), retina, combined retina/choroid/retinal pigment epithelium, sclera, and iris/ciliary body were developed to examine samples. Methods: Thirty male DBR were subconjunctivally injected in both eyes with 0.1 mL of LS of 1,000 μg/mL. At selected times post-injection, ocular tissues and whole blood samples were obtained. Sirolimus concentrations were measured using liquid chromatography/tandem mass spectrometry. Results: No LS was detected in serum or AH at any time. All other examined ocular tissues had quantifiable amounts of LS at all times. LS levels were highest in sclera and lowest in VH, suggesting LS followed the supraciliary and suprachoroidal spaces to reach the posterior segment. Vitreous peak of sirolimus levels occurred at 2 h, and the sclera adjacent to the injection peaked at both 2 and 96 h. LS levels in remaining ocular tissues peaked at 6 h and decreased with time, persisting at presumed therapeutic levels on day 22. Conclusions: LS can quickly diffuse into posterior intraocular tissues after SCJ injection without reaching quantifiable levels in AH or serum in DBR. Peak levels occurred in posterior intraocular tissues at 6 h and persisted in all tissues after 3 weeks. SCJ LS in DBR is safe, has a stable pharmacokinetic profile, and should be considered for further study in human trials for autoimmune ophthalmopathies.

A comprehensive review of intravitreal immunosuppressants and biologicals used in ophthalmology

Systemic immunosuppressants and biologicals have been a valuable tool in the treatment of inflammatory diseases and malignancies. The safety profile of these drugs has been debatable, especially in localized systems, such as the eye. This has led to the search for fairly local approaches, such as intravitreal, subconjunctival, and topical route of administration. Immunosuppressants have been used as a second-line drug in patients intolerable to corticosteroids or those who develop multiple recurrences on weaning corticosteroids. Similarly, biologicals have also been used as the next line of therapy, when adequate control of inflammation could not be attained or immunosuppressants were contraindicated to patients. Intravitreal immunosuppressants, such as methotrexate and sirolimus, have been extensively studied in noninfectious posterior uveitis, whereas limited studies have established the efficacy of intravitreal biologicals, such as infliximab and adalimumab. Most of these drugs have shown good safety profile and tolerability in animal studies alone and have not been studied further in human subjects. However, most of the studies in literature are single-case reports or case series which limits the level of evidence. In this comprehensive review, we discuss the mechanism of action, pharmacodynamics, pharmacokinetics, indications, efficacy, and side effects of different intravitreal immunosuppressants and biologicals that have been studied in literature.

Therapeutic Effect of Rapamycin-Loaded Small Extracellular Vesicles Derived from Mesenchymal Stem Cells on Experimental Autoimmune Uveitis

Autoimmune uveitis is a major cause of vision loss and glucocorticoids are major traditional medications, which may induce serious complications. Rapamycin has been demonstrated to exhibit immunosuppressive effects and is promising to be used in treating uveitis by intravitreal injection. However, repeated and frequent intravitreal injections increase the risk of severe ocular complications, while the efficacy of subconjunctival injection of rapamycin is low since it is difficult for rapamycin to penetrate eyeball. Recently, small extracellular vesicles (sEVs) have attracted considerable research interest as natural drug delivery systems that can efficiently cross tissues and biological membranes. SEVs derived from mesenchymal stem cells (MSC-sEVs) also can exert immunosuppressive effect and ameliorate experimental autoimmune uveitis (EAU). The aim of this study was to construct a Rapamycin-loaded MSC-sEVs delivery system (Rapa-sEVs) and investigate its therapeutic effect on EAU by subconjunctival injection. Rapa-sEVs were prepared by sonication and characterized by nanoparticle tracking analysis, transmission electron microscopy, and western blotting. Clinical and histological scores were obtained to assess the treatment efficacy. Additionally, T cell infiltration was evaluated by flow cytometry. The results indicated that Rapa-sEVs could reach the retinal foci after subconjunctival injection. Compared to sEVs and rapamycin alone, Rapa-sEVs can produce a more marked therapeutic effect and reduce ocular inflammatory cell infiltration. Overall, MSC-sEVs have significant potential for the delivery of rapamycin to treat EAU. Subconjunctival injection of Rapa-sEVs may be contender for efficacious steroid-sparing immunomodulatory therapy.

Intravitreal lupeol: A new potential therapeutic strategy for noninfectious uveitis

Lupeol is a pentacyclic triterpene with known anti-inflammatory effects. However, its role in the treatment of noninfectious uveitis has not been explored. This work investigated anti-inflammatory activity of lupeol in ocular tissues with in vitro and in vivo models. First, we evaluated the effect of lupeol (100 µM) on inflammatory response induced by lipopolysaccharide (LPS) in retinal pigment epithelium cells (ARPE-19) by measuring levels of released interleukins (IL-6 and IL-8). Then, we investigated the anti-inflammatory action of intravitreal lupeol in a rodent model of panuveitis induced by Mycobacterium bovis Calmette-Guérin Bacillus (BCG). Rats were submitted to electroretinography and clinical analyses on days 3, 7, and 15 after uveitis induction. In addition, histopathological analysis, and indirect quantification of myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) in the posterior segment were performed. Treatment with lupeol (100 µM) significantly decreased IL-6 and IL-8 levels in comparison to untreated LPS-activated ARPE-19 cells. This reduction was similar to that detected in ARPE-19 cells treated with dexamethasone. The results of the in vivo assay demonstrated that intravitreal lupeol is able to modulate inflammation in the anterior and posterior segment of the rat eyes, indicating that it should be further investigated as a novel potential candidate for management of uveitis.

Erdheim-Chester disease: a comprehensive review from the ophthalmologic perspective

Erdheim-Chester disease (ECD) is a rare clonal histiocytic neoplasm with less than 1200 documented cases to date. The disease is life-threatening and difficult to recognize, although increasing awareness as well as the integration of clinical, imaging, pathology information , and genetic studies have led to a recent exponential increase in new reported cases. ECD affects multiple organs and systems, including skeletal, neurologic, and cardiovascular. Pulmonary, retroperitoneal, and cutaneous lesions have also been reported in various combinations. Until the discovery that more than half of ECD patients harbor the BRAF-V600E mutation or other mutations in the mitogen-activated protein kinase (MAPK) and RAS pathways, Interferon-a was the first-line treatment. Nowadays BRAF and MEK-inhibitors targeted therapies are the mainstay of treatment. Ophthalmologic involvement occurs in 25% -30% of ECD cases, usually in the form of orbital involvement presenting with exophthalmos and ophthalmoplegia. Other ophthalmologic manifestations include palpebral xanthelasmas, anterior uveitis and vitritis, optic disk edema, choroidal infiltration, recurrent serous retinal detachment, retinal drusen-like deposits and retinal pigment epithelial changes. ECD patients can also present with ocular symptoms as a result of adverse effects of the treatment regimens. In some cases with smoldering or protean symptoms, the emergence of eye manifestations triggered the diagnosis. Ophthalmologists have to be aware of the disease, recognize the constellation of ECD symptoms, and contribute to the diagnosis, treatment, and follow-up of ECD patients.

Toxicity Evaluation of a Novel Rapamycin Liposomal Formulation After Subconjunctival and Intravitreal Injection

Purpose: Safety and toxicity evaluation of a novel, liposome-encapsulated rapamycin formulation, intended for autoimmune ocular disorders. Methods: The formulation was assessed by micronucleus polychromatic erythrocyte production, irritability by Hen's Egg Test-Chorioallantoic Membrane (HET CAM), sterility, and pyrogenicity testing. Subconjunctival (SCJ) and intravitreal (IVT) administration of the formulation were performed to evaluate subacute and acute toxicity, respectively. Differences between groups in biochemical and hematological parameters were evaluated by analysis of variance and t-tests. Numeric score was assigned to histopathological classification. Electroretinography (ERG) testing was also performed. Data were analyzed by a 1 way no parametric Kruskal-Wallis and the Mann-Whitney tests. Significance was considered when P < 0.05. Results: No significant toxicity directly related to the preparation was detected. Micronucleus count, mucous irritation score, and pyrogenicity results were negative. Pathology demonstrated no damage related to the formulation after SCJ injection. After IVT injection, only lens injury associated with technique was observed. Retinal function was also conserved in ERG. Conclusions: The preparation evaluated offers a good toxicity and safety profile when injected in a SCJ or IVT manner in an animal model. A clinical trial conducted in humans is highly warranted, as it could reveal an alternative immunosuppressive treatment for ophthalmological immune-mediated pathologies.

Biologic and advanced immunomodulating therapeutic options for sarcoidosis: a clinical update

Introduction: Sarcoidosis is a multi-organ disease with a wide range of clinical manifestations and outcomes. A quarter of sarcoidosis patients require long-term treatment for chronic disease. In this group, corticosteroids and cytotoxic agents be insufficient to control diseaseAreas covered: Several biologic agents have been studied for treatment of chronic pulmonary and extra-pulmonary disease. A review of the available literature was performed searching PubMed and an expert opinion regarding specific therapy was developed.Expert opinion: These agents have the potential of treating patients who have progressive disease. Many of these agents have different mechanisms of action, response rates, and toxicity profiles.

A Review of Local Therapy for the Management of Cystoid Macular Edema in Uveitis

ABSTRACT

Uveitic macular edema is a significant cause of visual impairment in most uveitis types. Treatment options of uveitis have advanced remarkably in recent years. Up to now, corticosteroids remain the mainstay of treatment. Nonsteroidal immunomodulators, and recently the biologic agents, which can reinforce efficacy and enable discontinuation or reduction of steroids to maintenance doses, are becoming increasingly popular in the management of uveitic macular edema. Several medications can be used in intraocular delivery and more and more sustained releasing implants are being developed. This review will briefly focus on the review of local therapy for the management of cystoid macular edema in uveitis, as many of these novel approaches are currently being evaluated in clinical trials.

PYK-1105: Preclinical Evaluation of a Novel Biodegradable Vitreous Substitute for Retinal Tamponade

Purpose:

Current retinal tamponade strategies are limited by anatomic considerations (retinal break location), durability (short-term vs need for removal), and patient adherence (positioning, travel/altitude restrictions). Here we describe the preclinical safety and toxicology of a novel biodegradable hydrogel tamponade agent (PYK-1105) with the potential to improve both patient experience and outcomes after retina surgery.

Methods:

We studied in vitro performance to assess hydrogel gelation time, modulus, viscosity, degradation time, refractive index, and transmittance. In addition to studying in vitro and in vivo (mice and rabbits) biocompatibility, testing was performed to assess cytotoxicity, intraocular irritation, acute systemic toxicity, genotoxicity, and pyrogenicity. Furthermore, clinical safety was assessed using in vivo (rabbits and minipigs) response to vitrectomy with PYK-1105 insertion with the following measures: clinical examination, multimodal imaging, full-field electroretinography, and histopathology.

Results:

PYK-1105 met the predefined performance testing criteria for optimal tamponade and demonstrated excellent biocompatibility. Animal studies showed the PYK-1105 formulation to be well tolerated and nontoxic in mice, rabbits, and pigs.

Conclusions:

PYK-1105 holds promise as a new biodegradable tamponade agent that has the potential to improve both the patient experience and outcomes after retina surgery. Human pilot studies are warranted to further assess for safety and efficacy.

New therapies in development for the management of non-infectious uveitis: A review

Uveitis is a spectrum of inflammatory disorders characterized by ocular inflammation and is one of the leading causes of preventable visual loss. The main aim of the treatment of uveitis is to control the inflammation, prevent recurrences of the disease and preserve vision while minimizing the adverse effects associated with the therapeutic agents. Initial management of uveitis relies heavily on the use of corticosteroids. However, monotherapy with high-dose corticosteroids is associated with side effects and cannot be maintained long term. Therefore, steroid-sparing agents are needed to decrease the burden of steroid therapy. Currently, the therapeutic approach for non-infectious uveitis (NIU) consists of a step-ladder strategy with the first-line option being corticosteroids in various formulations followed by the use of first-, second- and third-line agents in cases with suboptimal steroid response. Unfortunately, the agents currently at our disposal have limitations such as having a narrow therapeutic window along with their own individual potential side-effect profiles. Therefore, research has been targeted to identify newer drugs as well as new uses for older drugs that target specific pathways in the inflammatory response. Such efforts are made in order to provide targeted and safer therapy with reduced side effects and greater efficacy. Several specially designed molecular antibodies are currently in various phases of investigations that can potentially halt the inflammation in patients with NIU. In the review, we have provided a comprehensive overview of the current and upcoming therapeutic options for patients with NIU.

Efficacy and Safety of Intravitreal Sirolimus for Noninfectious Uveitis of the Posterior Segment: Results from the Sirolimus Study Assessing Double-Masked Uveitis Treatment (SAKURA) Program

PURPOSE

To evaluate the efficacy and safety of intravitreal sirolimus in the management of noninfectious uveitis of the posterior segment (NIU-PS).

DESIGN

Combined analysis of 2 phase 3, randomized, double-masked, multinational, 6-month studies.

PARTICIPANTS

Adults with active NIU-PS (intermediate uveitis, posterior uveitis, or panuveitis; defined as vitreous haze [VH] ≥1.5+ on modified Standardization of Uveitis Nomenclature scale).

METHODS

Patients were randomized 1:1:1 to receive intravitreal sirolimus 44 μg (n = 208), 440 μg (n = 208), or 880 μg (n = 177) on days 1, 60, and 120. Patients discontinued medications for NIU-PS except for systemic corticosteroids, which were tapered according to protocol. Enrollment in the 880-μg group was terminated after interim results found no significant difference in efficacy compared with the 440-μg dose.

MAIN OUTCOME MEASURES

The primary efficacy end point was the percentage of patients with VH of 0 at month 5 in the study eye without the use of rescue therapy. Secondary efficacy end points included VH of 0 or 0.5+, corticosteroid-tapering success, and changes in best-corrected visual acuity (BCVA). Safety measures included ocular and nonocular adverse events.

RESULTS

A total of 592 patients were randomized. Significantly higher proportions of patients treated with 440 μg compared with 44 μg intravitreal sirolimus achieved VH of 0 (21.2% vs. 13.5%; P = 0.038) and VH of 0 or 0.5+ (50.0% vs. 40.4%; P = 0.049) at month 5. Best-corrected visual acuity was stable (absolute change <5 ETDRS letters) or improved >5 letters in 80.1% and 80.2% of patients in the 440-μg and 44-μg groups, respectively. At month 5, corticosteroids were tapered successfully in 69.6% and 68.8% of patients in the 440-μg and 44-μg groups, and among these patients, VH of 0 or 0.5+ was achieved by 43.5% and 28.1% in the 440-μg and 44-μg groups. Both doses were generally well tolerated. Mean changes from baseline intraocular pressure (IOP) in the study eye at each analysis visit were minimal in all treatment groups.

CONCLUSIONS

Intravitreal sirolimus 440 μg improved ocular inflammation, as measured by VH, compared with the 44-μg dose, with minimal impact on IOP, while preserving BCVA.

In vivo and in vitro toxicity evaluation of liposome-encapsulated sirolimus

Background

To evaluate the in vivo and in vitro toxicity of a new formulation of liposome-encapsulated sirolimus (LES).

Methods

In vitro experiments were done using ARPE-19 and HRP cells. An MTT assay was used to determine cell metabolic activity and a TUNEL assay for detecting DNA fragmentation. In vivo experiments were conducted on New Zealand albino rabbits that received intravitreal injections of empty liposomes (EL) or different concentrations of LES. Histopathological and immunohistochemical analyses were performed on the rabbit’s eyes following injection.

Results

Eighteen eyes of nine rabbits were used. MTT assay cell viability was 95.04% in group 1 (12.5 µL/mL LES). 92.95% in group 2 (25 µL/mL LES), 91.59% in group 3 (50 µL/mL LES), 98.09% in group 4 (12.5 µL/mL EL), 95.20% on group 5 (50 µL/mL EL), 98.53% in group 6 (50 µL/mL EL), and 2.84% on group 8 (50 µL/mL DMSO). There was no statistically significant difference among groups 1 to 7 in cell viability (p = 1.0), but the comparison of all groups with group 8 was significant (p < 0.0001). The TUNEL assay comparing two groups was not statistically significant from groups 1 to 7 (p = 1.0). The difference between groups 1 to 7 and group 8 (p < 0.0001) was significant. Histopathological changes were not found in any group. No activation of Müller cells was detected.

Conclusion

A novel formulation of LES delivered intravitreally did not cause in vitro toxicity, as evaluated by MTT and TUNEL assays, nor in vivo toxicity as evaluated by histopathology and immunohistochemistry in rabbit eyes.

Emerging drugs for the treatment of noninfectious uveitis

Introduction: Uveitis is a leading cause of visual impairment and a significant burden of blindness. Although corticosteroids and conventional immunosuppressive agents have been successfully used, these are non-specific, and their long-term use may induce significant adverse effects. Areas covered: This article discusses existing local and systemic applied treatments for ocular inflammation including corticosteroids, non-biologic, and biologic disease-modifying anti-rheumatic drugs (DMARD). Potential drugs being studied in clinical trials are introduced for both local and systemic use. Expert opinion: Treatment options for uveitis continue to expand. Still, more efforts and research are needed to better understand the mechanisms potentially leading to clinical trials.

Emerging therapies in the management of macular edema: a review

Macular edema (ME) is a major complication of several vascular and inflammatory retinal diseases. Multiple mechanisms are implicated in its development and lead to visual impairment that could be reversible (the acute stages) or not reversible (long-standing ME). For this reason, an effective approach to the treatment of ME is of paramount importance in order to prevent irreversible damage of visual function. In this review, we discuss the management of ME and, in particular, current data of studies and clinical trials about drugs that have already been evaluated or are under investigation in the management of ME. Although several diseases could lead to the development of ME, we focus on the three main causes: diabetic retinopathy (DR), retinal vein occlusion (RVO), and uveitis. The introduction into clinical practice of anti-vascular endothelial growth factor injections (ranibizumab and aflibercept) and dexamethasone implants has revolutionized the treatment of ME secondary to DR and RVO. However, new drugs are needed in the treatment of resistant forms of ME secondary to DR and RVO. A fluocinolone acetonide implant has been approved by the US Food and Drug Administration for the treatment of diabetic ME but not for RVO. Furthermore, brolucizumab and abicipar pegol have been shown to be effective in preliminary studies and have the chance to be approved soon for diabetic ME treatment. In ME secondary to uveitis, a crucial role is played by corticosteroids and non-biologic immunomodulatory drugs. However, several new biologic agents are under investigation in different clinical trials and could be important new therapeutic options in cases with a low response to first-line therapy. However, only a few of these drugs will enter the market after proving their safety and efficacy. Only after that will we be able to offer a new therapeutic option to patients affected by uveitic ME.

Safety and efficacy of tacrolimus-coated silicone plates as an alternative to mitomycin C in a rabbit model of conjunctival fibrosis

Purpose

To find safer and more effective drugs than mitomycin C to prevent conjunctival fibrosis in a rabbit model.

Methods

Twenty-four rabbits were involved and randomly divided into four groups. Limbus-based peritomy was performed at the superior cornea, and normal saline (NS group), mitomycin C (MMC group), SR (SR group), or TC (TC group)-coated silicone plate was inserted at the sub-Tenon’s space in each group. Conjunctival congestion was evaluated at 1 and 4 weeks postoperatively. At 4 weeks, the numbers of inflammatory cells, fibroblasts, myofibroblasts, blood vessels, and goblet cells were counted in the conjunctiva and Tenon’s capsule around the silicone plate.

Results

At 4 weeks, conjunctival congestion was significantly less than that observed at 1 week in the SR and TC groups (p < 0.05), whereas the number of myofibroblasts was significantly lower in the MMC and TC groups (p < 0.05). The conjunctiva was significantly less congested in the TC group versus the other groups at 1 week and 4 weeks (p < 0.05). The TC group had the lowest number of inflammatory cells and MMC group had the lowest number of goblet cells among all groups (p < 0.05).

Conclusions

The TC-coated silicone plate was more effective in inhibiting inflammation and fibrosis versus the MMC-coated silicone plate and was associated with fewer adverse effects in the rabbit model.

Outcomes of treatment with sirolimus for non-infectious uveitis: a meta-analysis and systematic review

Background

Uveitis is a group of intraocular inflammatory diseases whose primary treatment involves immunosuppression. Although corticosteroids (CSs) remain the mainstay therapy, sirolimus is among the recently studied immunomodulatory drugs for treating noninfectious uveitis (NIU).

Objective

The aim of this review was to assess and summarize the updated evidence on the outcomes of treatment with sirolimus for NIU.

Materials and methods

Two reviewers conducted a systematic search on November 5, 2018, of electronic databases (EMBASE, MEDLINE, and The Cochrane Library) and clinical trial registers having no restrictions on language or publication date. The primary outcome was uveitis activity as measured by vitreous haze (VH), while the secondary outcomes included central macular thickness (CMT), best-corrected visual acuity (BCVA), CS-sparing effect, IOP elevation, and other adverse events. A meta-analysis was conducted on selected studies with appropriate clinical and methodological homogeneity.

Results

Seven studies were included and reviewed. Four randomized clinical trials were eligible for meta-analysis: SAVE 2013, One-year outcomes of the SAVE study, SAVE 2 2016, SAKURA 2016. The pooled proportions of inflammation control (VH improvement) were 38% (95% CI 16.19%-62.66%) during a 6-month follow-up and 49.97% (95% CI 16.19%-83.03%) during a 6- to 12-month follow-up with the latter showing a significantly higher response rate (p=0.0472). BCVA improvement was 62.2% (95% CI 33.17%-87.11%) during a 6-month follow-up and 56.86% (95% CI 20.91%-89.05%) during a 6- to 12-month follow-up with no significant difference between the two (p=0.3705). Increased IOP remained at 7.11% (95% CI 3.46%-12.68%) for both a 6-month follow-up and up to a 12-month follow-up duration. The CS-sparing effect of sirolimus was also well demonstrated. A reduction in CMT was observed, and only minor drug-related adverse events were reported in all the studies reviewed.

Conclusion

This review provided evidence that sirolimus is a promising treatment option for controlling inflammatory activity, improving visual acuity, and sparing CS use with minor adverse events for NIU.

Update in treatment of uveitic macular edema

Macular edema (ME) represents the most common cause for visual loss among uveitis patients. The management of uveitic macular edema (UME) may be challenging, due to its often recalcitrant nature. Corticosteroids remain the mainstay of treatment, through their capability of effectively controlling inflammation and the associated ME. Topical steroids may be effective in milder cases of UME, particularly in edema associated with anterior uveitis. Posterior sub-Tenon and orbital floor steroids, as well as intravitreal steroids often induce rapid regression of UME, although this may be followed by recurrence of the pathology. Intra-vitreal corticosteroid implants provide sustained release of steroids facilitating regression of ME with less frequent injections. Topical nonsteroidal anti-inflammatory drugs may provide a safe alternative or adjuvant therapy to topical steroids in mild UME, predominantly in cases with underlying anterior uveitis. Immunomodulators including methotrexate, mycophenolate mofetil, tacrolimus, azathioprine, and cyclosporine, as well as biologic agents, notably the anti-tumor necrosis factor-α monoclonal antibodies adalimumab and infliximab, may accomplish the control of inflammation and associated ME in refractory cases, or enable the tapering of steroids. Newer biotherapies have demonstrated promising outcomes and may be considered in persisting cases of UME.

Toxicity and in vivo release profile of sirolimus from implants into the vitreous of rabbits' eyes

PURPOSE

To assess the in vivo release profile and the retinal toxicity of a poly (lactic-co-glycolic acid) (PLGA) sustained-release sirolimus (SRL) intravitreal implant in normal rabbit eyes.

METHODS

PLGA intravitreal implants containing or not SRL were prepared, and the viability of ARPE-19 and hES-RPE human retinal cell lines was examined after 24 and 72 h of exposure to implants. New Zealand rabbits were randomly divided into two groups that received intravitreal implants containing or not SRL. At each time point (1-8 weeks), four animals from the SRL group were euthanized, the vitreous was collected, and drug concentration was calculated. Clinical evaluation of the eyes was performed weekly for 8 weeks after administration. Electroretinography (ERG) was recorded in other eight animals, four for each group, at baseline and at 24 h, 1, 4, 6, and 8 weeks after the injection. ERG was carried out using scotopic and photopic protocols. The safety of the implants was assessed using statistical analysis of the ERG parameters (a and b waves, a and b implicit time, B/A ratio, oscillatory potential, and Naka-Rushton analysis) comparing the functional integrity of the retina between the PLGA and SRL-PLGA groups. After the last electrophysiological assessment, the rabbits were euthanized and retinal histopathology was realized.

RESULTS

After 24 and 72 h of incubation with PLGA or SRL-PLGA implants, ARPE-19 and hES-RPE cells showed viability over 70%. The maximum concentration of SRL (199.8 ng/mL) released from the device occurred within 4 weeks. No toxic effects of the implants or increase in the intraocular pressure was observed through clinical evaluation of the eye. ERG responses showed no significant difference between the eyes that received PLGA or SRL-PLGA implants at baseline and throughout the 8 weeks of follow-up. No remarkable difference in retinal histopathology was detected in rabbit eyes treated with PLGA or SRL-PLGA implants.

CONCLUSIONS

Intravitreal PLGA or SRL-PLGA implants caused no significant reduction in cell viability and showed no evident toxic effect on the function or structure of the retina of the animals. SRL was released from PLGA implant after application in the vitreous of rabbits during 8 weeks.

Effect of Rapamycin Microspheres in Sjögren Syndrome Dry Eye: Preparation and Outcomes

Purpose: To prepare a drug delivery system of rapamycin poly-3-hydroxybutyrate-co-3-hydroxyvalerate microspheres (RPM) and analyze its effect on the eyes of a Sjögren's syndrome mouse model.Methods: RPM was generated using a solvent evaporation method, and observed under light and electron microscopy. No obesity diabetes (NOD) mice with Sjögren's syndrome were randomized into normal saline, empty microspheres, and RPM groups, with healthy Kunming mice as the controls. Dry eye signs were assessed using a slit lamp. Tear secretion, corneal fluorescein, keratoconjunctival rose bengal, and conjunctival impression cytology were recorded.Results: RPM was smooth and spherical, about 20-50 μm in diameter, without agglomeration or adhesion. Mice receiving RPM secreted more tears. And they had a normal corneal histology, exhibiting reduced corneal fluorescein, rose bengal staining, and conjunctival impression cytology.Conclusion: RPM improved the signs of dry eyes, improved tear secretion, decreased corneal endothelial cell injury, and improved histological damage of the cornea in NOD mice.

Intravitreal therapeutic agents in noninfectious uveitic macular edema

The management of uveitis is challenging for most treating ophthalmologists. The treatment of uveitis often requires the use of high dose of systemic corticosteroid and immunosuppressive agents, which are almost always associated with potential side effects. Intravitreal medications have become a popular mode of drug administration in uveitis patients as they provide high volume of drug to the target tissues, eliminating the risk of systemic toxicity. There has been tremendous development in the intravitreal therapeutics over the last few years. With the advent of sustained-release technique, increasing patient compliance, biodegradable nature of the implant, and introduction of newer agents with better safety profile, the intravitreal medications have become more popular in recent years. This review presents evidence in the scientific literature supporting the use of intravitreal medications for the management of uveitis and its complications.

Intravitreal Sirolimus for the Treatment of Noninfectious Uveitis: Evolution through Preclinical and Clinical Studies

In recent decades, the treatment paradigm for noninfectious intermediate uveitis, posterior uveitis, and panuveitis, a group of intraocular inflammatory diseases, has included systemic and local (periocular or intraocular) corticosteroids, biologics, and other steroid-sparing immunomodulatory therapy agents. Recently, an intravitreal formulation of sirolimus, an immunosuppressant that inhibits the mammalian target of rapamycin, a key regulator of cell growth in the immune system, was developed. On the basis of this mechanism and the local method of delivery, it was hypothesized that intravitreal sirolimus can improve ocular inflammation in patients with noninfectious intermediate uveitis, posterior uveitis, and panuveitis, with minimal systemic exposure and systemic adverse events (AEs). This review summarizes the pharmacokinetics, efficacy, and safety results of intravitreal sirolimus from 3 preclinical studies and 4 phase 1-3 clinical studies. Preclinical studies in rabbits showed that 22 to 220 μg intravitreal sirolimus results in sustained release of sirolimus in the vitreous for 2 months or more, with systemic concentrations below the threshold for systemic immunosuppression (approximately 8 ng/ml). Subsequently, 2 phase 1 studies (n = 50 and n = 30) established that intravitreal sirolimus improves ocular inflammation in humans. Further investigation in phase 2 and 3 studies (n = 24 and n = 347, respectively) suggested that 440 μg has the best benefit-to-risk profile. In the phase 3 study, the proportion of patients who showed complete resolution of ocular inflammation at month 5 was significantly higher in the 440-μg group than in the 44-μg group (22.8% vs. 10.3%; P = 0.025, Fisher exact test). In addition, 47 of 69 patients (68.1%) who were treated with systemic corticosteroids at baseline discontinued corticosteroid use at month 5. No sirolimus-related systemic AEs were reported in phase 1-3 studies. Collectively, these preclinical and clinical study data of intravitreal sirolimus support the therapeutic rationale of treating noninfectious uveitis with a local mammalian target of rapamycin inhibitor and suggest that 440 μg intravitreal sirolimus has the potential to be an effective and well-tolerated anti-inflammatory and corticosteroid-sparing treatment for noninfectious intermediate uveitis, posterior uveitis, and panuveitis.

A systematic review and economic evaluation of adalimumab and dexamethasone for treating non-infectious intermediate uveitis, posterior uveitis or panuveitis in adults

BACKGROUND

Non-infectious intermediate uveitis, posterior uveitis and panuveitis are a heterogeneous group of inflammatory eye disorders. Management includes local and systemic corticosteroids, immunosuppressants and biological drugs.

OBJECTIVES

To evaluate the clinical effectiveness and cost-effectiveness of subcutaneous adalimumab (Humira^®; AbbVie Ltd, Maidenhead, UK) and a dexamethasone intravitreal implant (Ozurdex^®; Allergan Ltd, Marlow, UK) in adults with non-infectious intermediate uveitis, posterior uveitis or panuveitis.

DATA SOURCES

Electronic databases and clinical trials registries including MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and the World Health Organization's International Clinical Trials Registry Platform were searched to June 2016, with an update search carried out in October 2016.

REVIEW METHODS

Review methods followed published guidelines. A Markov model was developed to assess the cost-effectiveness of dexamethasone and adalimumab, each compared with current practice, from a NHS and Personal Social Services (PSS) perspective over a lifetime horizon, parameterised with published evidence. Costs and benefits were discounted at 3.5%. Substantial sensitivity analyses were undertaken.

RESULTS

Of the 134 full-text articles screened, three studies (four articles) were included in the clinical effectiveness review. Two randomised controlled trials (RCTs) [VISUAL I (active uveitis) and VISUAL II (inactive uveitis)] compared adalimumab with placebo, with limited standard care also provided in both arms. Time to treatment failure (reduced visual acuity, intraocular inflammation, new vascular lesions) was longer in the adalimumab group than in the placebo group, with a hazard ratio of 0.50 [95% confidence interval (CI) 0.36 to 0.70; p < 0.001] in the VISUAL I trial and 0.57 (95% CI 0.39 to 0.84; p = 0.004) in the VISUAL II trial. The adalimumab group showed a significantly greater improvement than the placebo group in the 25-item Visual Function Questionnaire (VFQ-25) composite score in the VISUAL I trial (mean difference 4.20; p = 0.010) but not the VISUAL II trial (mean difference 2.12; p = 0.16). Some systemic adverse effects occurred more frequently with adalimumab than with placebo. One RCT [HURON (active uveitis)] compared a single 0.7-mg dexamethasone implant against a sham procedure, with limited standard care also provided in both arms. Dexamethasone provided significant benefits over the sham procedure at 8 and 26 weeks in the percentage of patients with a vitreous haze score of zero (p < 0.014), the mean best corrected visual acuity improvement (p ≤ 0.002) and the percentage of patients with a ≥ 5-point improvement in VFQ-25 score (p < 0.05). Raised intraocular pressure and cataracts occurred more frequently with dexamethasone than with the sham procedure. The incremental cost-effectiveness ratio (ICER) for one dexamethasone implant in one eye for a combination of patients with unilateral and bilateral uveitis compared with limited current practice, as per the HURON trial, was estimated to be £19,509 per quality-adjusted life-year (QALY) gained. The ICER of adalimumab for patients with mainly bilateral uveitis compared with limited current practice, as per the VISUAL trials, was estimated to be £94,523 and £317,547 per QALY gained in active and inactive uveitis respectively. Sensitivity analyses suggested that the rate of blindness has the biggest impact on the model results. The interventions may be more cost-effective in populations in which there is a greater risk of blindness.

LIMITATIONS

The clinical trials did not fully reflect clinical practice. Thirteen additional studies of clinically relevant comparator treatments were identified; however, network meta-analysis was not feasible. The model results are highly uncertain because of the limited evidence base.

CONCLUSIONS

Two RCTs of systemic adalimumab and one RCT of a unilateral, single dexamethasone implant showed significant benefits over placebo or a sham procedure. The ICERs for adalimumab were estimated to be above generally accepted thresholds for cost-effectiveness. The cost-effectiveness of dexamethasone was estimated to fall below standard thresholds. However, there is substantial uncertainty around the model assumptions. In future work, primary research should compare dexamethasone and adalimumab with current treatments over the long term and in important subgroups and consider how short-term improvements relate to long-term effects on vision.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041799.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Treatment of Geographic Atrophy with Intravitreal Sirolimus: The Age-Related Eye Disease Study 2 Ancillary Study

Objective/Purpose

To evaluate efficacy and safety of monthly intravitreal injections of sirolimus, an immunosuppressive drug, for the treatment of age-related macular degeneration associated geographic atrophy (GA).

Design

Randomized, controlled, single-masked multi-center phase 2 clinical trial of intravitreal sirolimus vs. sham therapy in AREDS2 clinical centers.

Subjects

Participants with GA.

Methods

Participants eligible in one eye were randomly assigned to a monthly intravitreal injection of sirolimus (20 µL [440 µg]) or sham treatment while participants with two study eyes were assigned to a monthly intravitreal injection in a randomly-selected eye. Best-corrected visual acuities (BVCA), spectral domain optical coherence tomography (OCT), fundus color photography and fundus autofluorescence (FAF) images were obtained at baseline and every 6 months until visit month 24.

Main Outcome Measures

Rate of progression of GA (mm²/year) measured on color fundus photograph from baseline to 24 months. Secondary outcome measures include change in BVCA, worsening of vision by ≥3 lines, and changes in area of GA measured on FAF and OCT.

Results

52 participants (mean age 79 years) were enrolled with 27 study eyes assigned to sirolimus from May 2012 to March 2014. The baseline median area of GA was 4.73 DA (12.01 mm²). The mean (standard deviation) growth rates of GA detected on color fundus photographs were 2.27 (2.17) mm² and 1.91 (2.27) mm² at month 12, and 4.94 (2.96) mm² and 5.72 (3.97) mm² at month 24, for the sirolimus and sham groups, respectively. There was no statistically significant difference in the GA growth rates between the two treatment groups (P=0.33). Median visual acuity changes and incidence of 15-letter loss from baseline were not different between the 2 treatment groups (p=0.19). The intervention was stopped early because of sterile endophthalmitis that occurred in 3 participants in the sirolimus group. Participants were followed for safety until the study was closed in May 2015 due to lack of efficacy.

Conclusion

Sirolimus did not result in different rates of GA growth in this phase 2 study. Immunosuppression may be important for some stages of the AMD process but may not necessarily be the main pathway for the development of GA.

Novel everolimus-loaded nanocarriers for topical treatment of murine experimental autoimmune uveoretinitis (EAU)

In the present study, therapeutic effect of topically applied everolimus (EV)-loaded methoxy-poly(ethylene-glycol)-hexyl substituted poly (lactic acid) (mPEGhexPLA) nanocarriers on experimental autoimmune uveoretinitis (EAU) were investigated. EAU was induced in B10.RIII mice via immunization with human interphotoreceptor retinoid-binding protein peptide 161-180 (hIRBPp161-180) in complete Freund's adjuvant. Everolimus-loaded mPEGhexPLA (EV/mPEGhexPLA) nanocarriers were prepared by using a solvent evaporation method. On days 12-21 postimmunization (p.i.), the right eyes were treated five times daily either with 10 μl of 0.5% everolimus formulation or PBS (control). The EAU score of the eyes was determined histologically. On day 21 p.i., the peripheral immune responses were measured in serum, cervical lymph nodes (LN), and spleens via hIRBPp161-180-specific serum antibodies, cytokine secretion (ELISA), lymphocyte proliferation, and FoxP3+ regulatory T cells (Treg; flow cytometry). Compared to the PBS-treated mice, unilateral topical everolimus treatment significantly reduced EAU severity in both eyes (p < .05). The treatment reduced the antigen (Ag)-specific hIRBPp161-180-induced proliferation (p < .05), IL-2, IL-17, and IFN-γ secretion from cells isolated from the left and right cervical LN (p < .05). Under everolimus treatment, IL-10 secretion and CD4⁺CD25⁺FoxP3⁺ Treg frequency from cervical LN were enhanced. The proliferative response and cytokine secretion as well as the frequency of splenic Treg were almost unchanged. Topical administration of an everolimus formulation improved EAU in both eyes. The effect might also be related to systemic immunosuppressive effects, as several systemic cellular immune responses were influenced.

Non-Infectious Uveitis: Optimising the Therapeutic Response

Non-infectious uveitis mainly affects the working-age population and can contribute to significant social and economic burden. It comprises a heterogeneous group of conditions with varied aetiology. Precise and early diagnosis, excluding masquerade syndromes, is the key to early therapeutic intervention. Treatment should be appropriately selected according to the anatomical sites of inflammation, the diagnosis and known prognosis, and whether there is a systemic inflammatory drive. Corticosteroids in the form of local or systemic therapy form the mainstay of treatment; however, due to unacceptable side effects, the need for long-term use or suboptimal response, corticosteroid-sparing medications may need to be considered early on in the management of non-infectious uveitis. With newer insights into the immunopathology of uveitis and the availability of biologic agents, treatment can be tailored according to individual needs. Many patients have systemic involvement, and hence a multidisciplinary approach is often required to achieve the best outcome in an individual. Patient involvement in the management of non-infectious uveitis, ensuring compliance, and continual monitoring of both the treatment and therapeutic response are the key to achieving optimal outcomes.

Assessment of vitreous haze using ultra-wide field retinal imaging

Background

Conventional fundus imaging has been used to assess vitreous haze (VH) in patients with uveitis. Ultra-wide field (UWF) retinal imaging that uses scanning laser technology has not been evaluated for the detection of VH. This pilot study evaluates the ability of UWF imaging in detecting VH.

Patients with intermediate, posterior, or panuveitis were examined to assess the level of VH using slit-lamp biomicroscopy. Colored fundus images were acquired using a Carl Zeiss FF450 camera. The same photographer obtained fundus images of the same eyes during the same visit by Optos UWF P200Tx retinal camera. Two graders independently analyzed UWF fundus images for presence or absence of VH, without quantifying the degree of VH using any scale. The images were analyzed using the composite red plus red-free wavelengths utilized by the Optos UWF camera and by using each wavelength exclusively. These findings were compared to clinical detection of VH and detection of VH using conventional fundus photography.

Results

Ninety-two eyes were included in the study. For composite UWF images, sensitivity was 0.27, specificity was 0.88, PPV was 0.31, NPV was 0.86, positive LR was 2.25, and negative LR was 0.83. For the conventional Zeiss images, sensitivity was 0.5, specificity was 0.84, PPV was 0.33, NPV was 0.91, positive LR was 3.13, and negative LR was 0.6.

Agreement between the composite UWF and Zeiss techniques was substantial with k = 0.64. Inter-observer agreement for composite UWF images was also substantial with k = 0.65. Inter-observer agreement for Zeiss images was moderate with k = 0.471. Intra-observer agreement for both imaging modalities was substantial with a composite UWF k = 0.76 and Zeiss k = 0.7.

Conclusions

UWF fundus imaging using scanning laser technique may be used to assess VH and employed in the management of intermediate, posterior, and panuveitis.

Intravitreal Sirolimus for Noninfectious Uveitis: A Phase III Sirolimus Study Assessing Double-masKed Uveitis TReAtment (SAKURA)

PURPOSE

To evaluate the efficacy and safety of intravitreal sirolimus in the treatment of noninfectious uveitis (NIU) of the posterior segment (i.e., posterior, intermediate, or panuveitis).

DESIGN

Phase III, randomized, double-masked, active-controlled, 6-month study with intravitreal sirolimus.

PARTICIPANTS

Adults with active NIU of the posterior segment (intermediate, posterior, or panuveitis), defined as a vitreous haze (VH) score >1+. Subjects discontinued NIU medications before baseline, except for systemic corticosteroids, which were allowed only for those already receiving them at baseline and were rapidly tapered after baseline per protocol.

METHODS

Intravitreal sirolimus assigned 1:1:1 at doses of 44 (active control), 440, or 880 μg, administered on Days 1, 60, and 120.

MAIN OUTCOME MEASURES

The primary efficacy outcome was the percentage of subjects with VH 0 response at Month 5 (study eye) without use of rescue therapy. Secondary outcomes at Month 5 were VH 0 or 0.5+ response rate, corticosteroid tapering success rate (i.e., tapering to a prednisone-equivalent dosage of ≤5 mg/day), and changes in best-corrected visual acuity (BCVA). Adverse events during the double-masked treatment period are presented.

RESULTS

A total of 347 subjects were randomized. Higher proportions of subjects in the intravitreal sirolimus 440 μg (22.8%; P = 0.025) and 880 μg (16.4%; P = 0.182) groups met the primary end point than in the 44 μg group (10.3%). Likewise, higher proportions of subjects in the 440 μg (52.6%; P = 0.008) and 880 μg (43.1%; P = 0.228) groups achieved a VH score of 0 or 0.5+ than in the 44 μg group (35.0%). Mean BCVA was maintained throughout the study in each dose group, and the majority of subjects receiving corticosteroids at baseline successfully tapered off corticosteroids (44 μg [63.6%], 440 μg [76.9%], and 880 μg [66.7%]). Adverse events in the treatment and active control groups were similar in incidence, and all doses were well tolerated.

CONCLUSIONS

Intravitreal sirolimus 440 μg demonstrated a significant improvement in ocular inflammation with preservation of BCVA in subjects with active NIU of the posterior segment.

The Effect of Different Dosing Schedules of Intravitreal Sirolimus, a Mammalian Target of Rapamycin (mTOR) Inhibitor, in the Treatment of Non-Infectious Uveitis (An American Ophthalmological Society Thesis)

PURPOSE

To determine if two different doses of intravitreal sirolimus, an mTOR inhibitor, can decrease inflammation and is safe in eyes with non-infectious posterior, intermediate, or panuveitis in the Sirolimus as a Therapeutic Approach UVEitis: Protocol-2 (SAVE-2) Study.

METHODS

SAVE-2 is a prospective randomized, phase II, open-label interventional clinical trial conducted at 4 clinical centers in the United States. Eligible subjects were randomized into one of two treatments. Group 1 received 440µg of intravitreal sirolimus in study eyes on days 0, 30, 60, 90, 120, and 150; group 2 received 880µg of intravitreal sirolimus on days 0, 60, and 120. Fellow eyes were also eligible to receive sirolimus (of opposite dose to that of study eye). Primary endpoint of the study was at month 6 (M6).

RESULTS

24 subjects have been randomized in SAVE-2 and are included in the analysis. Vitreous haze decreased by ≥2 steps in 63.6% and 50% of patients in groups 1 and 2, respectively at M6 (p=0.695). Mean change in best-corrected visual acuity for subjects was +3.66 and -2.91 ETDRS letters in group 1 and 2, respectively. Among subjects with macular edema at baseline (n=13), the mean change in foveal thickness was -89.42µm in group 1 and +81.5µm in group 2 at M6.

CONCLUSIONS

Both low and high doses of intravitreal sirolimus were found to decrease vitreous haze in eyes with non-infectious uveitis. Low dose (440µg) sirolimus administered monthly may be more efficacious in reducing uveitic macular edema than high dose (880µg) administered every 2 months.

Sirolimus for the treatment of noninfectious uveitis

INTRODUCTION

Noninfectious posterior uveitis (NIPU) remains a significant burden of legal blindness. Because of its immune mediated and chronic recurrent nature, common therapy includes (systemic) corticosteroids and immune modulatory agents. Most treatments bear the risk of significant adverse effects. Therefore efforts are made to administer therapeutic agents directly into the vitreous cavity. The purpose of this article is to identify the role of intravitreally applied sirolimus as a recently approved therapeutic option in NIPU.

AREAS COVERED

A MEDLINE database search was conducted through August 2015 using the terms: intravitreal injection, pharmacology, sirolimus, treatment and uveitis. To provide ongoing and future perspectives in treatment options, also clinical trials as registered at ClinicalTrials.gov were included. Sirolimus (Opsiria) was in licensed from SANTEN in 2015 and approved in Phase III registration trials in the US, Europe and other countries for NIPU. Current information results mainly from registration and Phase III trials.

EXPERT OPINION

Intravitreal sirolimus appears to be an interesting option in the treatment algorithms of NIPU because of its highly targeted molecular effects, nonsteroidal nature and good safety profile. It has the advantage to avoid systemic side effects, but this has to be balanced against the fact that treatment covers one eye only and bears the risks of any intraocular procedure. Nevertheless a careful evaluation of this agent has to be made, as current experience is almost exclusively based on registration trials and long-term effects still have to be explored.

Uveitic macular edema

Macular edema (ME) may complicate anterior, intermediate, and posterior uveitis, which may be because of various infectious, neoplastic or autoimmune etiologies. BRB breakdown is involved in the pathogenesis of Uveitic ME (UME). Optical coherence tomography has become a standard tool to confirm the diagnosis of macular thickening, due to its non-invasive, reproducible, and sensitive features. Retinal fluorescein and indocyanine green angiography is helpful to study the macula and screen for associated vasculitis, detect ischemic areas and preretinal, prepapillary or choroidal neovascular complications, and it may provide information about the etiology and be needed to assess the therapeutic response. UME due to an infection or neoplastic infiltration may require a specific treatment. If it remains persistent or occurs in other etiologies, immunomodulatory treatments may be needed. Intravitreal, subconjunctival, or subtenon corticosteroids are widely used. Their local use is contraindicated in glaucoma patients and limited by their short-lasting action. In case of bilateral sight-threatening chronic posterior uveitis, systemic treatments are usually needed, and corticosteroids are used as the standard first-line therapy. In order to reduce the daily steroid dose, immunosuppressive or immunomodulatory agents may be added, some of them being now available intravitreally. Ongoing prospective studies are assessing biotherapies and immunomodulators to determine their safety and efficacy in this indication.

Novel strategies for the treatment of diabetic macular edema

Macular edema such as diabetic macular edema (DME) and diabetic retinopathy are devastating back-of-the-eye retinal diseases leading to loss of vision. This area is receiving considerable medical attention. Posterior ocular diseases are challenging to treat due to complex ocular physiology and barrier properties. Major ocular barriers are static (corneal epithelium, corneal stroma, and blood-aqueous barrier) and dynamic barriers (blood-retinal barrier, conjunctival blood flow, lymph flow, and tear drainage). Moreover, metabolic barriers impede posterior ocular drug delivery and treatment. To overcome such barriers and treat back-of-the-eye diseases, several strategies have been recently developed which include vitreal drainage, laser photocoagulation and treatment with biologics and/or small molecule drugs. In this article, we have provided an overview of several emerging novel strategies including nanotechnology based drug delivery approach for posterior ocular drug delivery and treatment with an emphasis on DME.

The Neuroprotective Effect of Rapamycin as a Modulator of the mTOR-NF-κB Axis during Retinal Inflammation

Purpose

The determination of the molecular mechanism underlying retinal pathogenesis and visual dysfunction during innate inflammation, and the treatment effect of rapamycin thereon.

Methods

The endotoxin-induced uveitis and retinitis mouse model was established by injecting lipopolysaccharide. The mice were subsequently treated with rapamycin, a mammalian target of rapamycin (mTOR) inhibitor. The rhodopsin mRNA and protein expression level in the retina and the photoreceptor outer segment (OS) length in immunohistochemical stainings were measured, and visual function was recorded by electroretinography. Inflammatory cytokines, their related molecules, mTOR, and LC3 levels were measured by real-time PCR and/or immunoblotting. Leukocyte adhesion during inflammation was analyzed using concanavalin A lectin.

Results

The post-transcriptional reduction in the visual pigment of rod photoreceptor cells, rhodopsin, OS shortening, and rod photoreceptor cell dysfunction during inflammation were suppressed by rapamycin. Activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and induction of inflammatory cytokines, such as interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1), and the activation of the downstream signaling protein, signal transducer and activator of transcription 3 (STAT3), which reduces rhodopsin in the retina during inflammation, were attenuated by rapamycin. Increased leukocyte adhesion was also attenuated by rapamycin. Interestingly, although mTOR activation was observed after NF-κB activation, mTOR inhibition suppressed NF-κB activation at the early phase, indicating that the basal level of activated mTOR was sufficient to activate NF-κB in the retina. In addition, the inhibition of NF-κB suppressed mTOR activation, suggesting a positive feedback loop of mTOR and NF-κB during inflammation. The ratio of LC3II to LC3I, which reflects autophagy induction, was not changed by inflammation but was increased by rapamycin.

Conclusions

Our results propose the potential use of rapamycin as a neuroprotective therapy to suppress local activated mTOR levels, related inflammatory molecules, and the subsequent visual dysfunction during retinal inflammation.

In Vitro and In Vivo Sustained Zero-Order Delivery of Rapamycin (Sirolimus) From a Biodegradable Intraocular Device

PURPOSE

We created implantable intraocular devices capable of constant and continuous rapamycin release on the scale of months to years.

METHODS

Polycaprolactone (PCL) thin films were used to encapsulate rapamycin to create implantable and biodegradable intraocular devices. Different film devices were studied by modifying the size, thickness, and porosity of the PCL films.

RESULTS

In vitro release of rapamycin was observed to be constant (zero-order) through 14 weeks of study. Release rates were tunable by altering PCL film porosity and thickness. In vivo release of rapamycin was observed out through 16 weeks with concentrations in the retina-choroid in the therapeutic range. Rapamycin concentration in the blood was below the lower limit of quantification. The drug remaining in the device was chemically stable in vitro and in vivo, and was sufficient to last for upwards of 2 years of total release. The mechanism of release is related to the dissolution kinetics of crystalline rapamycin.

CONCLUSIONS

Microporous PCL thin film devices demonstrate good ocular compatibility and the ability to release rapamycin locally to the eye over the course of many weeks.