Early Real World Data Of Two New Glaucoma Stents

To evaluate the early (3-6 month) outcomes of two newer glaucoma stent procedures and compare these to older more established procedures. Hydrus implantation was commenced at this hospital in May 2021, Preserflo implantation in December 2020. 

UK NHS district Hospital setting in an area with a large elderly predominantly Caucasian population. The department of ophthalmology has gained considerable experience over the years with MIGS procedures, initially Xen (now largely abandoned) and later with iStent implantation. The newer Hydrus trabecular implant and the Preserflo sub-conjunctival shunt device were introduced in the department in the last 12 months, each of the procedures aimed at a different subset of patients

 

34 Caucasian patients (mean age 78 range 56-92) received a Hydrus Shunt device as part of their phaco-emulsification for cataract. All patients had mild to moderate open angle glaucoma with a mean IOP of 21.7 on 2.6 medications. The preserflo group consisted of 19 patients (mean age 76, range 50-85) with more advanced glaucoma (neuro-retinal rim erosion, visual field loss), mean IOP 22 on 2.3 medications. All procedures were stand-alone augmented with Mitomcyin C applied topically in the sub-conjunctival space. The preserflo group consisted of both phakic and pseudo-phakic patients. with one having had a previous (failed) Xen implant.

63% in the Hydrus group had reached 3 month follow up with a mean IOP of 14.6 and no reduction in topical medication compared to pre-op (94% IOP below 18, 58% 15 mmHg or below). One failure occurred who went on to have Preserflo, no significant complications or visual loss occurred. 75% of the Preserflo group reached 3 month follow-up with a mean IOP of 10.3 mmHg on no topical medication. All patients had an IOP of less than 15 mmHg. Early numeric hypotony was common without AC shallowing, but was not persistent. Bleb leak occurred in three patients, one requiring re-suturing. No significant visual loss occurred in this group.

Although numbers are small and follow up limited the Hydrus implant compares favourably with the iStent trabecular implant carried out at this hospital(previous presented data: IOP drop from mean 23.7 to 16.9 on continued topical medication, n=96, 82% <18, 32% =<15 at 3 months) with a slightly larger IOP drop albeit from a higher base-line. Likewise the Preserflo data can be compared favourably to trabeculectomies audited between 2017 and 2019 (IOP drop from 26.1 to 14.7 mmHg on no medication at three months, n=29). The technical aspects and unwanted outcome profile of the newer procedures were not inferior to the more established operations. The higher incidence of bleb-leaks required careful attention to suturing technique