No, Floaters & sinusitis are less likely to be related unless the sinusitis is associated with any complications. Floaters are commonly associated with eye conditions like Myopia. It could be an orbital complication of sinusitis.
Next Steps
You might require a consultation of an Eye Specialist along with consultation of an ENT Surgeon like me.
Health Tips
You might definitely require a CT PNS with contrast s.o.s.