Can you tell me what is and which is the price for an trabeculectomy surgery?

Lower eye pressure. There's couple of types, but both are surgical treatments to lower your eye pressure. Cost is usually covered by your insurance. However, if your are self pay, then it can vary whether you have it done at a hospital or an ambulatory surgery center. They can range $4k-$10k if you are a cashing paying patient.
Eye "Filter" ~$10k. A trabeculectomy or "trab" is a controlled leak, of sorts, or a filter. It involves making a drainage route of fluid from inside to outside the eye. The outside of the eye being a bleb or bump of elevated conjunctiva usually seen above the iris after the surgery. In this way, the pressure inside the is lowere. The total cost of the surgery without surgery is likely around $10, 000.