LIGHTSITE III: 13-Month Efficacy and Safety Evaluation of Multiwavelength Photobiomodulation in Nonexudative (Dry) Age-Related Macular Degeneration Using the Lumithera Valeda Light Delivery System.

PURPOSE: The LIGHTSITE III study evaluated multiwavelength photobiomodulation (PBM) therapy in nonexudative (dry) age-related macular degeneration (AMD) using the LumiThera Valeda Light Delivery System. METHODS: LIGHTSITE III is a randomized, controlled trial to assess the safety and effectiveness of PBM in dry AMD. Subjects were given multiwavelength PBM (590, 660, and 850 nm) or Sham treatment delivered in a series of nine sessions over 3 to 5 weeks every four months over 24 months. Subjects were assessed for efficacy and safety outcomes. Data from the 13-month analysis are presented in this report. RESULTS: A total of 100 subjects (148 eyes) with dry AMD were randomized. LIGHTSITE III met the primary efficacy best-corrected visual acuity endpoint with a significant difference between PBM (n = 91 eyes) and Sham (n = 54 eyes) groups (Between group difference: 2.4 letters (SE 1.15), CI: -4.7 to -0.1, P = 0.02) (PBM alone: 5.4 letters (SE 0.96), CI: 3.5 to 7.3, P < 0.0001; Sham alone: 3.0 letters (SE 1.13), CI: 0.7-5.2, P < 0.0001). The PBM group showed a significant decrease in new onset geographic atrophy ( P = 0.024, Fisher exact test, odds ratio 9.4). A favorable safety profile was observed. CONCLUSION: LIGHTSITE III provides a prospective, randomized, controlled trial showing improved clinical and anatomical outcomes in intermediate dry AMD following PBM therapy.

Expression of key SARS-CoV-2 entry molecules in surgically obtained human retinal biopsies.

PURPOSE: To investigate the presence of ACE2, TMPRSS2 and Furin, i.e., a key player in the ocular infection with SARS-COV-2, in surgically obtained human retinal tissue samples from SARS-CoV-2-negative patients, using gene expression analysis. METHODS: The mechanisms and entry paths of ocular infections have been ill-defined so far. To better understand the possible entry routes, we used surgically explanted retinal tissue from nine patients that were not infected with SARS-CoV-2 and analyzed the message expression of the three key molecules that confer viral entry into cells using polymerase chain reaction. RESULTS: The median age of the patients (n = 9) included in the study was 52 years (IQR 48, 55). Eight patients underwent surgery for rhegmatogenous retinal detachment and one patient for tractional retinal detachment. Gene expression for the proteins studied was detected in all nine patients. The results of analysis by Livak's method (2001) demonstrated a median TMPRSS2 gene expression value of 20.9 (IQR 11.7, 33.7), a median ACE2 gene expression value of 2.09 (IQR 1.14, 2.79) and a median Furin gene expression value of 8.33 (IQR 5.90, 11.8). CONCLUSION: In conclusion, TMPRSS2, Furin and ACE2 are expressed in the retina and may contribute to the retinal involvement in COVID-19 patients. Expression may vary among individuals, which may explain why some patients may be more prone to retinal involvement during SARS-CoV-2 infection COVID-19 patients than others. Variability in the expression of TMPRSS2, Furin and ACE2 proteins themselves may also explain the presence or development of retinal symptoms of varying severity.

Using bioinformatic protein sequence similarity to investigate if SARS CoV-2 infection could cause an ocular autoimmune inflammatory reactions?

Although severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infection have emerged globally, findings related to ocular involvement and reported cases are quite limited. Immune reactions against viral infections are closely related to viral and host proteins sequence similarity. Molecular Mimicry has been described for many different viruses; sequence similarities of viral and human tissue proteins may trigger autoimmune reactions after viral infections due to similarities between viral and human structures. With this study, we aimed to investigate the protein sequence similarity of SARS CoV-2 with retinal proteins and retinal pigment epithelium (RPE) surface proteins. Retinal proteins involved in autoimmune retinopathy and retinal pigment epithelium surface transport proteins were analyzed in order to infer their structural similarity to surface glycoprotein (S), nucleocapsid phosphoprotein (N), membrane glycoprotein (M), envelope protein (E), ORF1ab polyprotein (orf1ab) proteins of SARS CoV-2. Protein similarity comparisons, 3D protein structure prediction, T cell epitopes-MHC binding prediction, B cell epitopes-MHC binding prediction and the evaluation of the antigenicity of peptides assessments were performed. The protein sequence analysis was made using the Pairwise Sequence Alignment and the LALIGN program. 3D protein structure estimates were made using Swiss Model with default settings and analyzed with TM-align web server. T-cell epitope identification was performed using the Immune Epitope Database and Analysis (IEDB) resource Tepitool. B cell epitopes based on sequence characteristics of the antigen was performed using amino acid scales and HMMs with the BepiPred 2.0 web server. The predicted peptides/epitopes in terms of antigenicity were examined using the default settings with the VaxiJen v2.0 server. Analyses showed that, there is a meaningful similarities between 6 retinal pigment epithelium surface transport proteins (MRP-4, MRP-5, RFC1, SNAT7, TAUT and MATE) and the SARS CoV-2 E protein. Immunoreactive epitopic sites of these proteins which are similar to protein E epitope can create an immune stimulation on T cytotoxic and T helper cells and 6 of these 9 epitopic sites are also vaxiJen. These result imply that autoimmune cross-reaction is likely between the studied RPE proteins and SARS CoV-2 E protein. The structure of SARS CoV-2, its proteins and immunologic reactions against these proteins remain largely unknown. Understanding the structure of SARS CoV-2 proteins and demonstration of similarity with human proteins are crucial to predict an autoimmune response associated with immunity against host proteins and its clinical manifestations as well as possible adverse effects of vaccination.

A DOUBLE-MASKED, RANDOMIZED, SHAM-CONTROLLED, SINGLE-CENTER STUDY WITH PHOTOBIOMODULATION FOR THE TREATMENT OF DRY AGE-RELATED MACULAR DEGENERATION.

PURPOSE: The LIGHTSITE I study investigated the efficacy and safety of photobiomodulation (PBM) treatment in subjects with dry age-related macular degeneration. METHODS: Thirty subjects (46 eyes) were treated with the Valeda Light Delivery System, wherein subjects underwent two series of treatments (3× per week for 3-4 weeks) over 1 year. Outcome measures included best-corrected visual acuity, contrast sensitivity, microperimetry, central drusen volume and drusen thickness, and quality of life assessments. RESULTS: Photobiomodulation-treated subjects showed a best-corrected visual acuity mean letter score gain of 4 letters immediately after each treatment series at Month 1 (M1) and Month 7 (M7). Approximately 50% of PBM-treated subjects showed improvement of ≥5 letters versus 13.6% in sham-treated subjects at M1. High responding subjects (≥5-letter improvement) in the PBM-treated group showed a gain of 8 letters after initial treatment (P < 0.01) and exhibited earlier stages of age-related macular degeneration disease. Statistically significant improvements in contrast sensitivity, central drusen volume, central drusen thickness, and quality of life were observed (P < 0.05). No device-related adverse events were reported. CONCLUSION: Photobiomodulation treatment statistically improved clinical and anatomical outcomes with more robust benefits observed in subjects with earlier stages of dry age-related macular degeneration. Repeated PBM treatments are necessary to maintain benefits. These pilot findings support previous reports and suggest the utility of PBM as a safe and effective therapy in subjects with dry age-related macular degeneration.

Differentiation of Underlying Pathologies of Macular Edema Using Spectral Domain Optical Coherence Tomography (SD-OCT).

Purpose: To describe the morphological characteristics of macular edema (ME) of different origins using spectral domain optical coherence tomography (SD-OCT). Methods: This article summarizes and highlights key morphologic findings, based on published articles, describing the characteristic presentations of ME of different origins using SD-OCT. The following pathologies were included: uveitic macular edema, pseudophakic cystoid macular edema (PCME), diabetic macular edema (DME), macular edema secondary to central or branch retinal vein occlusion (CRVO/BRVO), microcystic macular edema (MME), ME associated with epiretinal membrane (ERM), and retinitis pigmentosa (RP). Conclusions: Macular edema of different origins show characteristic patterns that are often indicative of the underlying cause and pathology. Thus, trained algorithms may in the future be able to automatically differentiate underlying causes and support clinical diagnosis. Knowledge of different appearances support the clinical diagnosis and can lead to improved and more targeted treatment of ME.

The role of anti-VEGF agents in myopic choroidal neovascularization: Current standards and future outlook.

INTRODUCTION: The global prevalence of pathologic myopia is 0.9-3.1%, and visual impairment is found in 0.1-0.5% of European and 0.2-1.4% of Asian studies. Myopic choroidal neovascularization (mCNV) affects 5.2-11.3% of pathologic myopia patients and is a leading cause of vision impairment in the working-age population. Characteristic morphological changes and visual-acuity decrease are diagnostic features. Vascular-Endothelial-Growth-Factor (VEGF) has been identified as a trigger for pathologic neovascularization in these highly myopic patients. AREAS COVERED: We cover the epidemiology, pathology and diagnostic aspects of mCNV. The history of therapeutic interventions is described, followed by an overview of current standard-of-care (SOC)-blocking VEGF using bevacizumab (off-label), ranibizumab or aflibercept and improving vision up to 13.5-14.4 letters. Despite good efficacy, an unmet medical need remains. We summarize ongoing and future developments of new drugs to treat or potentially cure mCNV. EXPERT OPINION: mCNV is a major global health concern. Early detection and treatment is key for a satisfying outcome. The current SOC, VEGF inhibitors, affords good therapeutic efficacy and reasonable disease stabilization with few intravitreal treatments per year. However, the long-term prognosis is still unsatisfactory, and side-effects like chorioretinal atrophy development are of concern. Therefore, efforts should be intensified to develop more effective therapies.

Morphologic and functional evaluations during development, resolution, and relapse of uveitis-associated cystoid macular edema.

OBJECTIVES: To describe progression and resolution of uveitis-associated cystoid macular edema (uvCME) using spectral-domain optical coherence tomography and find predictive factors for successful intravitreal triamcinolone acetonide (IVTA) therapy. METHODS: Twenty-nine eyes with treatment-naive uvCME were examined before and at 5 scheduled visits within 3 months after intravitreal triamcinolone acetonide administration. Distribution, resolution, relapse, and development of uvCME were evaluated using spectral-domain optical coherence tomography to describe morphology, progression, and relapse according to a standardized reading protocol. Applying repeated measures analysis of variance, morphologic findings were evaluated as predictive factors of the treatment outcome. RESULTS: At baseline, 89.3% presented with focal CME; 65.6% had outer nuclear/Henley's layer and inner nuclear layer cysts. Following intravitreal triamcinolone acetonide administration, cysts of outer nuclear/Henley's layer diminished before those of inner nuclear layer (P = 0.0004). Small-pointed subretinal detachment (SRD) resolution synchronized with inner nuclear layer cyst extinction, whereas dome-shaped SRD resolution lagged behind (P = 0.014). Relapses of CME appeared in 71.4% of eyes with parafoveal inner nuclear layer cysts. Cysts of outer nuclear/Henley's layer were present in an additional 28.6%. None of the eyes developed SRD during CME relapse. The main effect variables "SRD" and "absence of epiretinal membrane" were associated with greater best-corrected visual acuity improvement (P = 0.05 and P = 0.047), whereas the side effect variables "CME duration", "age," and "uveitis location" had no additional effect on best-corrected visual acuity. Baseline SRD predicted a relapse-free clinical course within the observational period (P = 0.025). CONCLUSION: Different morphologic patterns in uvCME may represent different stages in uvCME progression, and initial morphologic appearance can be linked to the clinical prognosis after the treatment.

One-year outcomes of the da Vinci Study of VEGF Trap-Eye in eyes with diabetic macular edema.

PURPOSE: To compare different doses and dosing regimens of Vascular Endothelial Growth Factor (VEGF) Trap-Eye with laser photocoagulation in eyes with diabetic macular edema (DME). DESIGN: Randomized, double-masked, multicenter, phase 2 clinical trial. PARTICIPANTS: Diabetic patients (n = 221) with center-involved DME. METHODS: Participants were assigned randomly to 1 of 5 treatment regimens: VEGF Trap-Eye 0.5 mg every 4 weeks (0.5q4); 2 mg every 4 weeks (2q4); 2 mg every 8 weeks after 3 initial monthly doses (2q8); or 2 mg dosing as needed after 3 initial monthly doses (2PRN), or macular laser photocoagulation. MAIN OUTCOME MEASURES: The change in best-corrected visual acuity (BCVA) at 24 weeks (the primary end point) and at 52 weeks, proportion of eyes that gained 15 letters or more in Early Treatment of Diabetic Retinopathy Study (ETDRS) BCVA, and mean changes in central retinal thickness (CRT) from baseline. RESULTS: As previously reported, mean improvements in BCVA in the VEGF Trap-Eye groups at week 24 were 8.6, 11.4, 8.5, and 10.3 letters for 0.5q4, 2q4, 2q8, and 2PRN regimens, respectively, versus 2.5 letters for the laser group (P ≤ 0.0085 versus laser). Mean improvements in BCVA in the VEGF Trap-Eye groups at week 52 were 11.0, 13.1, 9.7, and 12.0 letters for 0.5q4, 2q4, 2q8, and 2PRN regimens, respectively, versus -1.3 letters for the laser group (P ≤ 0.0001 versus laser). Proportions of eyes with gains in BCVA of 15 or more ETDRS letters at week 52 in the VEGF Trap-Eye groups were 40.9%, 45.5%, 23.8%, and 42.2% versus 11.4% for laser (P = 0.0031, P = 0.0007, P = 0.1608, and P = 0.0016, respectively, versus laser). Mean reductions in CRT in the VEGF Trap-Eye groups at week 52 were -165.4 µm, -227.4 µm, -187.8 µm, and -180.3 µm versus -58.4 µm for laser (P < 0.0001 versus laser). Vascular Endothelial Growth Factor Trap-Eye generally was well tolerated. The most frequent ocular adverse events with VEGF Trap-Eye were conjunctival hemorrhage, eye pain, ocular hyperemia, and increased intraocular pressure, whereas common systemic adverse events included hypertension, nausea, and congestive heart failure. CONCLUSIONS: Significant gains in BCVA from baseline achieved at week 24 were maintained or improved at week 52 in all VEGF Trap-Eye groups. Vascular Endothelial Growth Factor Trap-Eye warrants further investigation for the treatment of DME.

The DA VINCI Study: phase 2 primary results of VEGF Trap-Eye in patients with diabetic macular edema.

PURPOSE: To determine whether different doses and dosing regimens of intravitreal vascular endothelial growth factor (VEGF) Trap-Eye are superior to focal/grid photocoagulation in eyes with diabetic macular edema (DME). DESIGN: Multicenter, randomized, double-masked, phase 2 clinical trial. PARTICIPANTS: A total of 221 diabetic patients with clinically significant macular edema involving the central macula. METHODS: Patients were assigned to 1 of 5 treatment regimens: 0.5 mg VEGF Trap-Eye every 4 weeks; 2 mg VEGF Trap-Eye every 4 weeks; 2 mg VEGF Trap-Eye for 3 initial monthly doses and then every 8 weeks; 2 mg VEGF Trap-Eye for 3 initial monthly doses and then on an as-needed (PRN) basis; or macular laser photocoagulation. Assessments were completed at baseline and every 4 weeks thereafter. MAIN OUTCOME MEASURES: Mean change in visual acuity and central retinal thickness (CRT) at 24 weeks. RESULTS: Patients in the 4 VEGF Trap-Eye groups experienced mean visual acuity benefits ranging from +8.5 to +11.4 Early Treatment of Diabetic Retinopathy Study (ETDRS) letters versus only +2.5 letters in the laser group (P ≤ 0.0085 for each VEGF Trap-Eye group vs. laser). Gains from baseline of 0+, 10+, and 15+ letters were seen in up to 93%, 64%, and 34% of VEGF Trap-Eye groups versus up to 68%, 32%, and 21% in the laser group, respectively. Mean reductions in CRT in the 4 VEGF Trap-Eye groups ranged from -127.3 to -194.5 µm compared with only -67.9 µm in the laser group (P = 0.0066 for each VEGF Trap-Eye group vs. laser). VEGF Trap-Eye was generally well tolerated. Ocular adverse events in patients treated with VEGF Trap-Eye were generally consistent with those seen with other intravitreal anti-VEGF agents. CONCLUSIONS: Intravitreal VEGF Trap-Eye produced a statistically significant and clinically relevant improvement in visual acuity when compared with macular laser photocoagulation in patients with DME.

Interleukin-15 stimulates macrophages to activate CD4+ T cells: a role in the pathogenesis of rheumatoid arthritis?

Interleukin-15 (IL-15) is a proinflammatory cytokine that is overexpressed in rheumatoid arthritis (RA), a disease characterized by activation of monocytes/macrophages (MPhi), and by expansion of autoreactive CD4(+) T cells. We hypothesized that IL-15 plays a major role for this expansion of CD4(+) T cells and modulates the phenotype of monocytes/MPhi and their interaction with CD4(+) T cells. Here, we show that IL-15 enhances the proliferation of CD4(+) T cells from patients with RA in peripheral blood mononuclear cell cocultures. To further dissect the underlying mechanisms, we employed MPhi from IL-15(-/-) or IL-15 transgenic mice. These were induced to differentiate or were stimulated with IL-15. Here we show that addition of IL-15 during differentiation of MPhi (into 'IL-15MPhi') and overexpression of IL-15 by MPhi from IL-15(tg) mice leads to increased levels of major histocompatibility complex class II expression. This resulted in enhanced stimulation of antigen-specific CD4(+) T cells in vitro and was accompanied by reduced messenger RNA expression in MPhi for immunosuppressive SOCS3. The proliferation rates of IL-15MPhi and IL-15(tg)MPhi were high, which was reflected by increased p27(Kip1) and reduced p21(Waf1) levels. In view of high serum and synovial levels of IL-15 in patients with RA, our data suggest the possibility that this excess IL-15 in RA may stimulate monocytes/MPhi to activate the characteristic autoreactive CD4(+) T cells in RA.

Interleukin-21: a new modulator of immunity, infection, and cancer.

Interleukin-21 is the most recently discovered member of the type-I cytokine family. Structurally, IL-21 shows homology to IL-2, IL-4, and IL-15 proteins. IL-21 shares the common gamma-chain with the other three cytokines but, in addition, binds to a unique IL-21Ralpha chain, and activates the JAK/STAT pathway. IL-21 is mainly produced by activated T-cells but targets a broad range of lymphoid and myeloid cells of the immune system and therefore is able to regulate innate and acquired immune responses. This review intends to give the reader an overview of the recent findings concerning the biology of IL-21 and its physiological role in immunity, infection, and cancer.

Soluble Interleukin IL-15Ralpha is generated by alternative splicing or proteolytic cleavage and forms functional complexes with IL-15.

Interleukin 15 (IL-15) is a pleiotropic cytokine that is hardly detectable in biological fluids. Here, we show that IL-15 forms functional heterocomplexes with soluble high affinity IL-15 receptor alpha (IL-15Ralpha) chain in mouse serum and cell-conditioned medium, which prevents IL-15 detection by ELISA. We also demonstrate that two soluble IL-15Ralpha (sIL-15Ralpha) sushi domain isoforms are generated through a novel alternative splicing mechanism within the IL-15Ralpha gene. These isoforms potentiate IL-15 action by promoting the IL-15-mediated proliferation of the CTLL cell line and interferon gamma production by murine NK cells, which suggests a role in IL-15 transpresentation. Conversely, a full-length sIL-15Ralpha ectodomain released by tumor necrosis factor-alpha-converting enzyme (TACE)-dependent proteolysis inhibits IL-15 activity. Thus, a dual mechanism of sIL-15Ralpha generation exists in mice, giving rise to polypeptides with distinct properties, which regulate IL-15 function.

Dendritic cell-derived IL-15 controls the induction of CD8 T cell immune responses.

The development and the differentiation of CD8(+) T cells are dependent on IL-15. Here, we have studied the source and mechanism of how IL-15 modulates CD8(+) T cell-mediated Th1 immune responses by employing two delayed-type hypersensitivity (DTH) models. IL-15-deficient (IL-15(-/-)) mice or mice treated with soluble IL-15Ralpha as an IL-15 antagonist showed significantly reduced CD8(+) T cell-dependent DTH responses, while activation of CD4(+) T cell and B cell functions remained unaffected. Injection of antigen-labeled dendritic cells (DC) from IL-15(+/+), IL-15(-/-) or IL-15Ralpha(-/-) mice revealed that DC-derived IL-15 is an absolute requirement for the initiation of DTH response. The re-establishment of the interaction of IL-15 with the IL-15Ralpha by incubating IL-15(-/-) DC with IL-15 completely restored the capacity to prime T cells for DTH induction in vivo. Moreover, IL-15 also enhanced secretion of pro-inflammatory cytokines by DC and triggered in vitro CD8(+) T cell proliferation and IL-2 release. Taken together, the data suggest that an autocrine IL-15/IL-15Ralpha signaling loop in DC is essential for inducing CD8(+)-dependent Th1 immune responses in mice. Therefore, targeted manipulation of this loop promises to be an effective, novel strategy for therapeutic modulation of clinically relevant DTH reactions.

Interleukin-21 inhibits dendritic cell activation and maturation.

Interleukin 21 (IL-21) is a newly described cytokine with homology to IL-4 and IL-15. They belong to a cytokine family that uses the common gamma chain for signaling but also have their private high-affinity receptors. Since it is well known that IL-4 modulates differentiation and activation of dendritic cells (DCs), we analyzed effects of IL-21 compared with IL-15 on DC differentiation, maturation, and function. Here we show that DCs generated with granulocyte-macrophage colony-stimulating factor (GMCSF) in the presence of IL-21 (IL-21DCs) differentiated into phenotypically and functionally altered DCs characterized by reduced major histocompatibility complex class II (MHCII) expression, high antigen uptake, and low stimulatory capacity for T-cell activation in vitro. Additionally, IL-21DCs completely failed to induce antigen (Ag)-specific T-cell mediated contact hypersensitivity. Furthermore, IL-21 blocked lipopolysaccharide (LPS)-induced activation and maturation of DCs, which was not mediated by release of the anti-inflammatory cytokine IL-10. In contrast, when supplementing GMCSF with IL-15, DCs differentiated into mature antigen-presenting cells (APCs) with low antigen uptake and highly significant increased capacities to stimulate T cells in vitro and in vivo. Taken together, these results identify a dichotomous action of these structurally related cytokines on DCs, establishing IL-21 as inhibitory cytokine on DC activation and IL-15 as potent stimulator of DC function, making both cytokines interesting targets for therapeutic manipulation of DC-induced immune reactions.