(A) with a thin base connected to the conjunctiva (B). No leakage could be seen (C). Black arrow: thin base connected to the conjunctiva.

(A). The inner passage of the ff ltration bleb was patent (B). White arrow: partial free edge. Yellow arrow: inner passage of the ff ltration bleb. 

(A). The bleb was wellmaintained six months after surgery (B) without leakage (C). 

Large overhanging blebs are an uncommon complication of glaucoma filtration surgery. Though the pathogenesis is unknown, it may be related to the use of MMC. Its shape varies, especially after application of MMC ⁽¹⁾. In the current case, the occurrence of such bleb appeared to be related to cataract surgery instead, evidenced by the following two signs. First, foreign body sensation and uncomfortable feeling appeared after the cataract surgery. Second, for the two-side phacoemulsification on the right eye, the side incision was on the superior peripheral cornea near the ff ltration bleb, which might be interrelated.

It has been reported that the size of functioning filtration bleb decreased and IOP increased after phacoemulsiff cation ⁽²⁾. There has also been a report of an inadvertent bleb developing after phacoemulsification ⁽³⁾. However, the current case may be the ff rst report of a post-trabeculectomy overhanging filtration bleb related to cataract surgery. The possible mechanism may be related to microleakage of the surgical wound of the side incision after phacoemulsiff cation which initiated the healing and scarring process ⁽³⁾. Thus, the morphology of the bleb is similar to a conjunctival granuloma with a thin base connected to the bleb.

Excision and revision of overhanging blebs are indicated when they are symptomatic or leaking. However, complications such as bleb leakage or failure occurred occasionally ⁽⁴⁾. Use of indocyanine green during excision or bleb revision guided by anterior segment optical coherence tomography has been reported with good results ⁽⁵⁾. Anis et al. reported sutureless revision with the aid of corneal contact lenses in six cases of overhanging filtering blebs ⁽⁴⁾. Success was achieved in five, while one patient had bleb leak requiring suture repair ⁽⁴⁾. In the current case, preoperative UBM impressions were confirmed by leakage of aqueous from the incision intraoperatively. Therefore, suture revision with superior conjunctival flap was performed with satisfactory outcome.