BackgroundGiant bleb formation after glaucoma tube shunt surgery is a rare condition and consensus regarding its management has not been established.Case presentationA 66-year-old Japanese man with primary open-angle glaucoma underwent implantation of an Ahmed glaucoma valve to reduce the intraocular pressure in his left eye. At 4 weeks postoperatively, he presented with a foreign body sensation in his left eye. A slit-lamp examination revealed a giant conjunctival cyst at the superotemporal quadrant and dellen formation at the corneal limbus/conjunctiva adjacent to the anterior border of the giant cyst. Ocular pain was due to a giant bleb that bulged anteriorly from the Ahmed glaucoma valve plate. Eight days after the referral, he underwent surgery to reduce the bleb volume in his left eye. To recess the bleb, the anterior edge of the dissected bleb capsule was sutured using two interrupted 10–0 absorbable sutures back to the sclera to the anterior edge of the Ahmed glaucoma valve plate. Three months postoperatively, there was no bleb around the corneal limbus, but the bleb was present around the plate.ConclusionsThe surgical technique reported here can be an option to relieve dellen-associated ocular pain due to a bleb formed after tube shunt surgery.