Preliminary antifibrotic and vasoconstrictor effects of adrenaline in Schlemm's canal and suprachoroidal minimally invasive glaucoma surgery in primary open-angle glaucoma.

PURPOSE: To investigate the antifibrotic and vasoconstrictor effects of adrenaline in Schlemm's canal and suprachoroidal minimally invasive glaucoma surgery (MIGS). METHODS: Human trabecular meshwork (TM) cells were treated with different concentrations of adrenaline (0%, 0.0005%, 0.01%), and we measured the effects on contractility, cell viability and the expression of key cell cycle and fibrosis genes. Adrenaline 0.05% was also injected intracamerally in five primary open-angle glaucoma patients undergoing iStent inject or MINIject surgery combined with phacoemulsification. All patients were assessed for ocular and systemic adverse reactions, including the effects on intraoperative pupil size, preoperative and postoperative visual acuity, intraocular pressure, and anterior segment OCT results. RESULTS: Adrenaline significantly reduced the contractility of TM cells in a dose-dependent manner (87.8%, 80.6%, 7.9% matrix contraction with adrenaline 0%, 0.0005%, 0.01%, respectively). Adrenaline did not exhibit any significant cytotoxicity even at high concentrations (P > 0.05). Adrenaline 0.01% significantly downregulated the expression of key cell cycle genes in the G2 and M phases, and also decreased the expression of MRTFB and ACTA2 genes (P < 0.05). Intracameral injections of adrenaline 0.05% in the five MIGS patients did not result in any ocular or systemic adverse effects. CONCLUSION: We recommend intracameral injections of adrenaline 0.05% as a cheap and safe drug to be used before MIGS insertion. Adrenaline decreases the risk of bleeding from the trabecular meshwork and also exhibits antifibrotic effects by arresting the cell cycle, thereby increasing the postoperative success rates in MIGS. KEY MESSAGE: What is known Fibrosis is the main cause of surgical failure in minimally invasive glaucoma surgery (MIGS). Mitomycin-C and 5-fluorouracil are too toxic to be used inside the eye. What is new Adrenaline reduced the contractility of trabecular meshwork cells and inhibited the expression of key cell cycle genes and fibrosis genes, without significant cytotoxicity. Intracameral injection of adrenaline 0.05% did not result in any ocular or systemic adverse reactions in MIGS patients.

Developing a synergistic rate-retarding polymeric implant for controlling monoclonal antibody delivery in minimally invasive glaucoma surgery.

Monoclonal antibodies (mAbs) have garnered substantial attention within the field of ophthalmology and can be used to suppress scar formation after minimally invasive glaucoma surgeries. Here, by controlling mAb passive diffusion, we developed a polymeric, rate-controlling membrane reservoir loaded with poly(lactic-co-glycolic acid) microspheres to deliver mAb for several weeks. Different parameters were tested to ensure that the microspheres achieved a good quality characteristic, and our results showed that 1 %W/V emulsifier with 5 %W/V NaCl achieved mAb-loaded microspheres with the highest stability, encapsulation efficiency and minimal burst release. Then, we fabricated and compared 10 types of microporous films based on polylactic acid (PLA), polycaprolactone (PCL), and polyethylene glycol (PEG). Our results revealed distinct pore characteristics and degradation patterns in different films due to varying polymer properties, and all the polymeric film formulations showed good biocompatibility in both human trabecular meshwork cells and human conjunctival fibroblasts. Finally, the optimized microspheres were loaded into the reservoir-type polymeric implant assembled by microporous membranes with different surface coating modifications. The implant formulation, which was fabricated by 60 PCL: 40 PEG (3 %W/V) polymer with 0.1 %W/V poly(lactic-co-glycolic acid) barrier, exerted the best drug release profile that can sustained release mAb (83.6 %) for 4 weeks.

Activation of GLP-1 receptor signalling by sacubitril/valsartan: Implications for patients with poor glycaemic control.

Sacubitril/valsartan is a first-in-class Angiotensin Receptor-Neprilysin inhibitor (ARNi) to be approved for the treatment of heart failure with reduced ejection fraction (HFrEF). The combination tablet has become a mainstay of treatment in the management of heart failure (HF) due to its composite inhibition of the neurohumoral system. There is growing support to show that sacubitril/valsartan may enhance glycaemic control through the augmentation of neprilysin substrates - in particular, glucagon-like peptide 1 (GLP-1). Given that HF and Diabetes Mellitus (DM) frequently coexist, with 44% of patients hospitalised with heart failure also having diabetes as a co-morbidity, it is plausible that sacubitril/valsartan may represent a novel way to address glucose intolerance in HF. However, the role of neprilysin in the degradation of GLP-1 raises important clinical considerations such as the risk of hypoglycaemia and potential drug-drug interactions in patients with and without concurrent DM. We review the current body of research addressing the effect of neprilysin inhibition on GLP-1 receptor signalling and discuss the implications for treatment of HF and DM.