Dehiscence of levator aponeurosis in ptosis after sub-Tenon injection of triamcinolone acetonide

Objective: To report the incidence, intraoperative findings, and surgical outcome of secondary ptosis that developed after a sub-Tenon injection of triamcinolone acetonide (TA). Study Design: Retrospective, cross-sectional study. Participants: One hundred forty-seven cases with a total of 286 sub-Tenon TA injections. Methods: The medical records of 163 eyes of 147 cases treated with a sub-Tenon injection of 10 mg or 20 mg TA were reviewed. The incidence of secondary ptosis (palpebral fissure >2 mm narrower than that of the fellow eye) after a sub-Tenon TA injection was determined. The preoperative levator function and margin reflex distance (MRD) of the affected eyes, and the intraoperative findings in eyes that underwent reconstructive surgery, were evaluated. Results: Eight eyes (5%) developed secondary ptosis after the injection and 6 eyes were treated by reconstructive surgery. The preoperative levator function of the affected eyes did not differ from that of the fellow eyes. Intraoperatively, no septal disruption or fat herniation was noted, but an aponeurotic disinsertion was identified and repaired with an advancement of the leading edge to the anterior tarsal plate. The surgery led to satisfactory results, with improvement of the MRD from -1.3 (SD 1.5) mm preoperatively to 2.3 (SD 0.5) mm postoperatively (p = 0.027). Additional sub-Tenon TA injections were required in 2 eyes after eyelid surgery but the ptosis did not worsen. Conclusions: A sub-Tenon TA injection can occasionally cause ptosis by inducing a disinsertion of the levator aponeurosis. However, surgical reconstruction can lead to successful resolution of the ptosis.