A vitrectomy probe includes a hand-graspable body and an outer tube extending from the hand-graspable body. The outer tube includes a closed distal end and a first port sized to receive tissue. The vitrectomy probe also includes an inner tube within the outer tube with a second port that is selectively alignable with a portion of the first port to allow fluid flow and uniquely sized to increase fluid flow. The inner tube includes a distal tip with a cutting edge on each of the distal and proximal sides of the tip. The distal tip has a smaller diameter than that of the inner tube at a proximal side of the second port. The proximal side of the second port includes a guiding surface that slidably bears on an inner surface of the outer tube to prevent the distal tip from excessively protruding from the first port of the outer tube.一種玻璃體切除術探針包括一手可抓握的主體及自該手可抓握的主體延伸的一外管。該外管包括一封閉的遠端及經設定大小來接收組織的一第一端口。該玻璃體切除術探針亦包括在該外管內具有一第二端口的一內管，該第二端口可選擇性地與該第一端口之一部分對準以允許流體流動且經設定獨特大小以增加流體流動。該內管包括一遠端尖端，具有該尖端之該等遠側及近側中之每一者上之切割邊緣。該遠端尖端的直徑小於該內管在該第二端口之一近側處的直徑。該第二端口之該近側包括滑動承載在該外管之一內表面上以阻止該遠端尖端自該外管之該第一端口過度突出的一導向表面。
