Pseudotendons after extraocular muscle surgery.

Following recession of a rectus muscle, a band of connective tissue designated as a pseudotendon may form between the recessed muscle tendon and the former insertion. The cut edges of the episclera at the former insertion and the sheath of the recessed muscle seem to be the primary sources of this vascularized connective tissue which replaces the avascular episclera which normally underlies the muscles. Repeated operations, excessive inflammatory reaction, injury to the sheath and intermingling of the conjunctiva and deeper wounds are predisposing factors. Pseudotendon formation does not reduce the effectiveness of a recession, because simple excision has little effect on the alignment of the eyes. Sometimes a well-formed pseudotendon can be used as a tendon to achieve additional recession of a previously recessed insertion.