The Outcome Of An Innovative Surgical Technique Connecting Preserflo Microshunt With Baerveldt Tube-350 In Patients With Refractory Glaucoma

This case series of four patients aims to evaluate the efficacy of a novel surgical technique combining a Preserflo MicroShunt (PMS) with a Baerveldt tube (BVT) in patients with refractory glaucoma to control the intraocular pressure within a targeted range.

East Lancashire Hospitals NHS Trust (a university teaching hospital) in the United Kingdom

A prospective observational case series of four patients with a combined PMS and a BVT procedure was performed. The primary outcome measurements were visual acuity (VA), intraocular pressure (IOP) and post-operation glaucoma medications. These outcomes were evaluated after the operation on the first day, first week, first month and three months. 

Three out of four patients were Asians, and one was of Caucasian descent. All of the patients were pseudophakic. Three had pre-existing PMS implants and one patient with pre-existing BVT implants. Patients had previous glaucoma procedures, including one with failed trabeculectomy and two with previous bleb revisions. The mean pre-operation IOP was 22mmHg with Diamox and two glaucoma mediations. Following combined PMS and BVT, the post-operation IOP were 10mmHg, 9mmHg, 12mmHg and 12mmHg on the first day, first week, first month and three months respectively. Three out of four patients were not on any glaucoma medications post-operation; only one was on Dorzolamide with Timolol eye drops starting in the third month.

This innovative surgical approach combines the advantages of both devices to control the IOP in patients with refractory glaucoma adequately. The small calibre of the Preserflo MicroShunt prevents excessive drainage of aqueous fluid and prevents corneal decompensation, whereas the Baerveldt plate provides a good reservoir to drain aqueous fluid out of the anterior chamber. This case series contributed new evidence that the combination of PMS and BVT is successful in maintaining a low IOP within a targeted range. A continuous long-term follow-up of these patients is needed to establish the safety and effectiveness of the combined devices.