An optical access apparatus for receiving an endoscope to permit visualization during passage through tissue includes an access member dimensioned for insertion through body tissue. The access member defines a longitudinal axis and has a longitudinal opening for receiving an endoscope. The access member has a closed penetrating end adapted to pass through tissue. The closed penetrating end is transparent to permit visualization of tissue with the endoscope. The optical access apparatus further includes a locking collet coaxially mounted relative to the longitudinal axis of the access member and a manual member mounted adjacent the locking collet and operatively engageable therewith. The locking collet has internal surfaces defining an internal passage to permit passage of the surgical instrument. The manual member is adapted for rotational movement about the longitudinal axis to reduce an internal dimension of the internal passage of the locking collet to cause the internal surfaces of the locking collet to securely engage the surgical instrument.