Purpose: To report treatment with hyaluronidase of lower lid swelling lasting for 1 year after retrobulbar hyaluronic acid filler injection due to phthisis bulbi. Case summary: A 54-year-old female presented with right lower eyelid swelling lasting 1 year. There was no tenderness in the right lower eyelid but Tyndall effect was observed. Ultrasonographic findings showed soft tissue swelling in the right lower eyelid. The patient had 3 mm enophthalmos in the right eye on exophthalmometry due to phthisis bulbi resulting from trauma 10 years prior to presentation. Retrobulbar hyaluronic acid filler (Juvederm voluma; Allergan, Irvine, CA, USA) injections were performed to increase orbital volume; 2 mL of filler was injected in the retrobulbar space twice at 1-month interval. After injections, the patient experienced right lower lid swelling lasting 1 year. The patient was diagnosed with lower eyelid swelling due to anterior filler displacement. Hyaluronidase (H-lase inj 1,500 IU/A; Gunil, Seoul, Korea) was reconstituted in 10 mL of normal saline and 0.1 mL (15 IU) of reconstituted hyaluronidase was injected into the right lower eyelid subcutaneously at 5 different areas. At 5 weeks following injections, the lower eyelid swelling was rarely observed and she was satisfied with the result. Conclusions: Long-lasting lower lid swelling after retrobulbar hyaluronic acid filler injection can be quickly and effectively treated with hyaluronidase injections. J Korean Ophthalmol Soc 2015;56(12):1961-1964