Prognosis Of Hydrus Implantion In Open Angle Glaucoma After 3 Years Follow Up

Review of 3 year follow up of patients having undergone combined phaco-emulsification and Hydrus trabecular bypass microstent implantation between 2021 and 2022 with a focus on IOP outcomes and medication use post-operatively as well as the risk of needing further intervention 

The authors work in a General District Hospital with a large eye department serving a mainly Caucasian and elderly population in the North of England. We have carried out MIGS procedures since 2016 and started with Hydrus in 2021. All operations were carried out by one of the authors (JvdH). Data in clinical notes was provided by a variety of colleagues as well as the authors. Our previous presentations at ESCRS congresses in the past have focussed on short term follow up data

Glaucoma patients presenting with cataract were offered the option of Hydrus microstent implantation at the same time as cataract surgery. Patients were reviewed post-op at 1 month, 3 month and then 6 monthly. The IOP at listing for surgery was taken as the pre-op IOP value; IOP was measured with Goldman (GAT) or ORA. The patient's electronic case records were used to collect the data for this review. Patients with a pre-op IOP of less than 18 mmHg were excluded as previous scrutinity of the Hydrus data had shown that low IOPs respond less well to Hydrus. An IOP lowering of 20% or more with an IOP of less than 22 mmHg was classed as success, the need for further intervention as failure. Pre-op meds were generally continued post-op

Between 2021 and 2022 53 patient received a Hydrus, of these 39 had pre-op IOP in excess of 18 mmHg (mean age 79 range 65-92, 45% female, mean pre-op IOP 22.5 mmHg range 18-29 on 2 medications). Two failed within 6 months (5%), a further 8 did not complete the minimum 36 follow up (4 died, 4 lost to follow up, half classed as succes at final review). At 36 months or more (mean 1297 days) 20 patients with hydrus (69%) were classed as success (mean IOP 15.5 range 10-21 on 1.8 medications). This was similar at 24 months postop, but higher success rates were seen at 6 and 12m postop (90 and 79% respectively on 1.9 medications). Severe complications were not encountered (beyond early mild post-op hyphaema), no corneal complications were seen

Our data shows that Hydrus implantation remains a useful adjunct in the management of the elderly glaucoma patient presenting with cataract and relatively poor IOP control. Only 5% of patients went on to have further surgery . We saw a relatively consistent rate of success beyond 24 months in two thirds of patients without late complications. Patients generally remain on their pre-op glaucoma medication although in individual cases a modest reduction of topical meds may be possible. Occasionally a treatment naive patient may not require post-op glaucoma medication following a Hydrus implant. The technique is not difficult to master and requires only a few minutes of additional surgical time when combined with cataract surgery