Lisa,
Yes we do perform asian or double eyelid surgery. The procedure is usually performed in the office under local anesthesia with some oral medications to relax the patient. Some patients prefer to have a deeper level of anesthesia at our surgery center, which can be arranged. 18 is certainly old enough to have the procedure. There is a limit as to how young someone can be, but it is variable based upon individual maturity levels. We would be happy to see you in consultation and discuss this further.
Ed Buckingham