SYNERGETIC SURGICAL APPROACH COMBINING PRESERFLO® MICROSHUNT AND BAERVELDT® GLAUCOMA IMPLANT FOR REFRACTORY GLAUCOMA: A NOVEL TECHNIQUE TO OPTIMIZE IOP CONTROL AND MINIMIZE COMPLICATIONS

To introduce a novel, integrative surgical technique that merges the PreserFlo® microshunt (PFMS) with the Baerveldt® glaucoma implant (BGI) to treat complex glaucoma cases.

Ophthalmology Department, Medical School Hannover, Hannover, Germany

This case series describes 4 eyes of 4 patients with complex primary open angle glaucoma who had previously undergone treatment with PFMS and exhibited postoperative scarring. During re-operation, the PFMS was left intracamerally. The filtering bleb was revised, and the PFMS was connected to the tube of a BGI which was implanted with a tuto patch covering both tubes. Number of prior surgeries, preoperative and postoperative number of medications, visual field (VF), global retinal nerve fiber layer (RNFL) thickness in Optical Coherence Tomography (OCT), intraocular pressure (IOP), corneal endothelial density (CED), postoperative complications, and re-operations were examined.

All patients were pseudophakic, had more than 2 cyclophotocoagulations, had PFMS with more than 2 bleb revisions each and 2 of 4 patients had previous trabeculectomy.

Preoperatively patients took on average 3,5±0,5 (n=4) glaucoma medications and systemic acetazolamide >500mg per day. Preoperatively the IOP was 31,5±10,07mmHg (n=4), the CED was 2022,43±40,8/mm², the mean deviation in VF was 18,53±5,96 dB (n=4), the global RNFL thickness in OCT was 60,5±17,8μm (n=4).

IOP was 10,0±5,72mmHg (n=4) 1 week postoperatively. One patient needed removal of both PFMS and BGI and implantation of Paul® Glaucoma Drainage Implant at the opposite quadrant.

After 1month IOP was 18,67±13,65mmHg (n=4) with 1 patient showing IOP at 38mmHg and nonfunctioning connected tubes, so that both PFMS and BGI had to be exchanged with new ones in the same position.

In the 3rd month after operation the IOP was 10±2,83mmHg (n=3) under no medication. VF was 18,6±4,95 dB (n=2), the global RNFL thickness in OCT was 44,5±0,71μm (n=2) and CED was 2006±5,66/mm² (n=2).

The combination of the BGI with an existing PFMS offers a promising surgical innovation for managing refractory glaucoma, particularly in patients with extensive surgical histories. This approach eliminated the need for another intraocular surgery. By using the PFMS as an internal stent, this method appears to reduce postoperative complications such as early hypertony and later corneal decompensation and hypotony, providing more predictable IOP control.