Insertion of a Preserflo microshunt inside a non-valved glaucoma shunt to treat late-onset hypotony

We present a case of advanced glaucoma with previously failed trabeculectomy who underwent a Baerveldt tube (BVT) insertion, with initial success. However, 9 months post BVT insertion he developed profound clinically significant hypotony. Two attempts at controlling this with suture exchange led to episodes of significant ocular hypertension, followed by hypotony each time. We describe a technique of using a cut segment of the novel, polystyrene?block?isobutylene?block? styrene (SIBs) based Preserflo Microshunt (Santen Inc., Miami, FL) inserted into the tip of a BVT to control late onset hypotony with success. IOP at 6 weeks was 12mmHg on two drops with complete resolution of the choroidal maculopathy