Anti-complement drugs for the treatment of geographic atrophy and the release of silicone oil

Intravitreal injections are a common procedure in ophthalmology, often using syringes coated with silicone to aid piston movement and needles coated with silicone oil to facilitate penetration of the sclera. Pegcetacoplan and avacincaptad pegol, recently approved for clinical use by the US Food and Drug Administration, have higher viscosity and seem more susceptible to entrap air bubbles compared to anti-VEGF drugs.It is plausible that both anti-complement drugs could be associated with a higher likelihood of introducing silicone oil in the vitreous because of higher viscosity, with potentially higher friction at the inner surface of syringe barrel, in the vicinity of silicone oil. In addition to this, undesirable agitation might be inadvertently promoted by some retina specialists to remove air bubbles from the drug solution.In conclusion, recent reports of silicone oil droplets in the vitreous of patients receiving pegcetacoplan injection might be related to both its viscosity and to agitation of the syringe to remove air bubbles. Since avacincaptad pegol also is viscous, though with different pH, syringe and filter needle, we might expect similar reports for this agent soon. We also recommend further studies be carried not only to clarify the current matter but also the potential association between the combination of agitation, silicone oil and inflammation or any immune response.