Một số vết rạch bên ngoài của mi mắt dưới để truy cập vành dưới ổ mắt và tầng quỹ đạo đã được mô tả. Sự khác biệt chính giữa chúng là mức độ mà tại đó vết rạch được đặt trong da của mí mắt và mức độ mà cơ thansected để lộ vách ngăn quỹ đạo / vỏ xương. Mỗi vết rạch có những lợi thế và bất lợi. | TECHNIQUE Several external incisions of the lower eyelid to gain access to the infraorbital rim and orbital floor have been described. The major difference between them is the level at which the incision is placed in the skin of the eyelid and the level at which the muscle is thansected to expose the orbital septum periosteum. Each incision has advantages and disadvantages. The approach shown here however is a standard approach that encompasses all of the techniques used in the others. It is most commonly called subciliary incision but is also known as infraciliary or blefharoplasty incision. This incision is merely a lower lid incision at a higher level that in the lower lid incision made just below the eyelashes. The main advantage of this incision is the imperceptible scar that it creates. Further it can be extended laterally for additional exposure of the entire lateral orbital rim. Once the skin is incised the surgeon has three options. The first is to dissect between the skin and the muscle until the orbital rim is reached at which point another incision through muscle and periosteum is made to the bone. The second option is to incise through muscle at the same level as the skin incision and dissect down just anterior to the orbital septum to the orbital rim. The third option is a combination of these in which subcutaneous dissection toward the rim proceeds for a few millimeters followed by incision through the muscle at a lower level producing a step-incision then following the orbital septum to the rim. Although all three options are advocated by several surgeons each has advantages and disadvantages. The first option in which a subcutaneous dissection to the level of the infraorbital rim is made leaves an extremely thin skin flap. This flap is technically difficult to elevate and accidental buttonhole dehiscence can occur. A further problem that may occasionally be seen is a slight darkening of the skin in this area after healing. Presumably the skin flap
