Vitreous humor proteome: unraveling the molecular mechanisms underlying proliferative and neovascular vitreoretinal diseases.

Proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR), and neovascular age-related macular degeneration (nAMD) are among the leading causes of blindness. Due to the multifactorial nature of these vitreoretinal diseases, omics approaches are essential for a deeper understanding of the pathophysiologic processes underlying the evolution to a proliferative or neovascular etiology, in which patients suffer from an abrupt loss of vision. For many years, it was thought that the function of the vitreous was merely structural, supporting and protecting the surrounding ocular tissues. Proteomics studies proved that vitreous is more complex and biologically active than initially thought, and its changes reflect the physiological and pathological state of the eye. The vitreous is the scenario of a complex interplay between inflammation, fibrosis, oxidative stress, neurodegeneration, and extracellular matrix remodeling. Vitreous proteome not only reflects the pathological events that occur in the retina, but the changes in the vitreous itself play a central role in the onset and progression of vitreoretinal diseases. Therefore, this review offers an overview of the studies on the vitreous proteome that could help to elucidate some of the pathological mechanisms underlying proliferative and/or neovascular vitreoretinal diseases and to find new potential pharmaceutical targets.

ILUVIEN® in diabetic macular edema that persists or recurs despite treatment: Results from the Retina.pt® RIVER audit.

PURPOSE: Persistent diabetic macular edema (DME) remains a problem in clinical practice, with many patients having a suboptimal response to the standard of care (SOC). Evidence supports the long-term efficacy of intravitreal fluocinolone acetonide (FAc) implant (ILUVIEN®) in patients that have responded sub-optimally, although there is still scarce data from real-world Portuguese practices. We aimed to monitor the current SOC in selected Portuguese practices prior to FAc implantation and then assess the long-term effectiveness and safety of the FAc implant. SETTINGS: The study included patient data from five Portuguese public hospitals. DESIGN: This was a non-interventional, multicenter audit of data collected from Retina.pt registry from patients with persistent or recurrent DME despite treatment. METHODS: Outcome measures included changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP). Results were compared at regular times over 36 months. RESULTS: This study included 222 eyes from 152 patients. A significant decrease in BCVA (P < 0.001) and a significant increase in CMT (P = 0.013) were observed prior to FAc. A significant increase in BCVA was registered at 6 months after FAc implant administration (P < 0.001), which was maintained during follow-up. No relevant changes in IOP were observed. Treatment burden was reduced as a result of treatment with FAc (P < 0.001 for anti-VEGF, corticosteroids, or both treatments) in the full population. CONCLUSIONS: In Portuguese practice, data showed that pre-FAc implantation, some patients did not respond to SOC treatment and/or they were undertreated. Following FAc implant administration, there were rapid, sustained, long-term visual and anatomical improvements, and a marked reduction in treatment burden.

Proteomics profiling of vitreous humor reveals complement and coagulation components, adhesion factors, and neurodegeneration markers as discriminatory biomarkers of vitreoretinal eye diseases.

Introduction: Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are leading causes of visual impairment and blindness in people aged 50 years or older in middle-income and industrialized countries. Anti-VEGF therapies have improved the management of neovascular AMD (nAMD) and proliferative DR (PDR), no treatment options exist for the highly prevalent dry form of AMD. Methods: To unravel the biological processes underlying these pathologies and to find new potential biomarkers, a label-free quantitative (LFQ) method was applied to analyze the vitreous proteome in PDR (n=4), AMD (n=4) compared to idiopathic epiretinal membranes (ERM) (n=4). Results and discussion: Post-hoc tests revealed 96 proteins capable of differentiating among the different groups, whereas 118 proteins were found differentially regulated in PDR compared to ERM and 95 proteins in PDR compared to dry AMD. Pathway analysis indicates that mediators of complement, coagulation cascades and acute phase responses are enriched in PDR vitreous, whilst proteins highly correlated to the extracellular matrix (ECM) organization, platelet degranulation, lysosomal degradation, cell adhesion, and central nervous system development were found underexpressed. According to these results, 35 proteins were selected and monitored by MRM (multiple reaction monitoring) in a larger cohort of patients with ERM (n=21), DR/PDR (n=20), AMD (n=11), and retinal detachment (n=13). Of these, 26 proteins could differentiate between these vitreoretinal diseases. Based on Partial least squares discriminant and multivariate exploratory receiver operating characteristic (ROC) analyses, a panel of 15 discriminatory biomarkers was defined, which includes complement and coagulation components (complement C2 and prothrombin), acute-phase mediators (alpha-1-antichymotrypsin), adhesion molecules (e.g., myocilin, galectin-3-binding protein), ECM components (opticin), and neurodegeneration biomarkers (beta-amyloid, amyloid-like protein 2).