FDA Approval of the Hydrus Microstent

Introduction

The Hydrus® Microstent is an implantable, flexible, metal (nitinol) tube with windows (open-back stent) pre-loaded onto a hand-held delivery system. The Hydrus® Microstent is intended to be used during cataract surgery for the reduction of intraocular pressure (IOP) in adult patients with mild to moderate POAG.The Hydrus® Microstent acts as a support structure in one part of the natural drainage pathway of the eye (Schlemm’s canal). POAG is a type of glaucoma where there is no other associated eye disease causing increased eye pressure and where the eye pressure usually rises slowly. This gradual increase in eye pressure can be associated with damage to the optic nerve. The device is designed to reduce eye pressure by re-establishing flow through Schlemm’s canal. It creates a bypass through the trabecular meshwork, and dilates and scaffolds the canal to augment outflow.

Khanna Institute Of Lasik
Khanna Institute Of Lasik

Approval Research Study

The approval of the MIGS device, the Hydrus Microstent was based upon the results of the HORIZON trial, which included 556 mild to moderate glaucoma patients who underwent cataract surgery. The patients were randomly assigned to receive either cataract surgery plus the Hydrus microstent or cataract surgery alone.

According to the trial results, more than 77% of patients who received the microstent experienced a statistically significant decrease in unmedicated IOP at 24 months postoperatively compared with 57.8% of patients who underwent cataract surgery alone. The device also reached its secondary effectiveness endpoint, with Hydrus patients achieving a mean IOP reduction of 7.5 mm Hg, which was a 2.3 mm Hg difference compared with the control group.

Intacs Patient

Comparison with iStent (First & Second Generation)

With the Hydrus Microstent, glaucoma-anterior segment surgeons now have a third microinvasive glaucoma surgery (MIGS) device option for indwelling canal trabecular micro-bypass as the Hydrus joins the first and second generation iStents (Glaukos) in this rapidly growing segment. The Hydrus is novel in several ways. First, it is comprised of nitinol, which has a long track record in human use. It has an 8-mm length, which when deployed extends nearly 3 full clock hours of the angle. This essentially eliminates the need for “intelligent placement,” in that the Hydrus spans the entire inferonasal quadrant and the rich supply of collector channels typically found in this region. Moreover, the Hydrus not only “stents” the canal providing a direct inlet from the anterior chamber to the canal, but also “tensions” the trabecular meshwork and inner wall. Outflow studies have confirmed that this tensioning further enhances outflow. The safety data, as with iStent, were also very favourable, not statistically different from the cataract surgery alone control arm.

Some surgeons may be intimidated by the 8-mm design, compared to the 1 mm length of the first generation iStent and the even smaller second generation iStent. However, they may be comforted by the fact that in the U.S. Pre-market approval (PMA) trial, 97% of patients randomized to Hydrus had successful implantation, 86% on the first attempt. Time will tell whether it is better to involve a larger portion of the canal as with Hydrus, or if the very focal and stealth iStent approach is better. The Hydrus, with its more expansive coverage can boast terrific efficacy data at 2 years. Meanwhile, those favoring the more stealth approach might argue that less manipulation may lead to less scarring long term. For now, based on the data from the FDA trials, both approaches are meaningful and a welcome addition to the MIGS portfolio.

Comparison Research Study

To compare the efficacy of different MIGS devices for reducing intraocular pressure (IOP) and medications in open-angle glaucoma (OAG), a research study was conducted.

Study participants included 152 eyes from 152 patients aged 45-84 years with OAG, Shaffer angle grade III-IV, Best-corrected visual acuity (BCVA) 20/30 or better, and IOP 23-39 mmHg after wash out of all hypotensive medications. Eyes with secondary glaucoma other than pseudo-exfoliative or pigmentary glaucoma, angle closure, previous incisional glaucoma surgery, or any significant ocular pathology other than glaucoma were excluded.

The differences were measured within-group and between-group differences in IOP and medications at 12 months and complete surgical success rates, defined as freedom from repeat glaucoma surgery, IOP 18 mmHg or less, and no glaucoma medications. Safety measures included the frequency of surgical complications, changes in visual acuity, slit lamp findings, and adverse event rates.

The Study groups were well matched for baseline demographics, glaucoma status, medication use and baseline IOP. Twelve months follow up was completed in 148/152 randomized subjects (97.3%). At 12 months, the Hydrus had a greater rate of complete surgical success (p<0.001) and reduced medication use (difference = -0.6 medications, p=0.004). More Hydrus subjects were medication free at 12 months (difference = 22.6% p=0.0057). Secondary glaucoma surgery was performed in 2 eyes in the 2 iStents group (3.9%) and in none of the Hydrus eyes. Two eyes in the Hydrus group and 1 in the 2 iStent group had BCVA loss of 2 lines.

Conclusions of the study were that standalone MIGS in open angle glaucoma with the Hydrus resulted in a higher surgical success rate and fewer medications compared to the 2 iStent procedures. The two MIGS devices have similar safety profiles.

Contraindications

The Hydrus® Microstent should not be used in patients who have any of the following conditions:

• When the colored part of the eye (iris) is pushed up against the drainage pathway or when other material blocks the drainage pathway (angle closure glaucoma);

• Traumatic glaucoma, malignant glaucoma, or inflammation of the eye tissue (uvea);

• Glaucoma associated with the growth of abnormal blood vessels in the eye (neovascular); or

• Noticeable birth irregularities of the anterior chamber (AC) angle.

Adverse Reactions

Common adverse events noted included device obstruction, worsening of visual field mean deviation by 2 dB or more, and BCVA loss of more than 2 ETDRS lines.

Generated

FDA Approval of the Hydrus Microstent

Introduction
The Hydrus ® Microstent is an implantable, versatile, steel (made up of nitinol) tube with windows (open-back stent) pre-loaded onto a hand-held delivery system for implantation into the eye. The Hydrus ® Microstent is intended to be made use of in cataract surgical treatment for the reduction of intraocular pressure (IOP) in grown-up patients with mild to modest POAG. The Hydrus ® Microstent acts as a support structure in one part of the all-natural drain path of the eye (Schlemm’s canal). POAG is a kind of glaucoma where there is no other connected eye illness creating increased eye pressure as well as where the eye stress normally increases slowly. This progressive boost in eye pressure can be related to damage to the optic nerve. The device is developed to lower eye stress by re-establishing circulation through Schlemm’s canal. It creates a bypass via the trabecular meshwork, and also dilates as well as scaffolds the canal to boost discharge.

Approval Research Study
The approval of the MIGS tool, the Hydrus Microstent was based upon the outcomes of the HORIZON test, which included 556 light to moderate glaucoma people who went through cataract surgical treatment. The individuals were arbitrarily selected to get either cataract surgery plus the Hydrus microstent or cataract surgical treatment alone.
According to the test results, more than 77% of people who received the microstent experienced a statistically considerable decline in unmedicated IOP at 24 months postoperatively compared with 57.8% of clients that went through cataract surgery alone. The device additionally reached its second efficiency endpoint, with Hydrus clients accomplishing a mean IOP decrease of 7.5 mm Hg, which was a 2.3 mm Hg difference compared with the control group.

Comparison with iStent (First & Secondly Generation).
With the Hydrus Microstent, glaucoma-anterior segment doctors now have a third microinvasive glaucoma surgical procedure (MIGS) tool choice for indwelling canal trabecular micro-bypass as the Hydrus joins the first and 2nd generation iStents (Glaukos) in this swiftly expanding sector. The Hydrus is unique in numerous ways. Initially, it is made up of nitinol, which has a long record in human usage. It has an 8-mm length, which when deployed extends virtually 3 complete clock hrs of the angle. This essentially eliminates the need for “smart positioning,” in that the Hydrus covers the entire inferonasal quadrant as well as the abundant supply of collector channels commonly located in this area. Moreover, the Hydrus not only “stents” the canal providing a straight inlet from the anterior chamber to the canal, however also “tensions” the trabecular meshwork and also internal wall. Discharge studies have confirmed that this tensioning additionally improves discharge and therefore reduces IOP. The safety data, just like that of the iStent, were likewise extremely good, not statistically different from the cataract surgical procedure alone control group.
Some doctors might be intimidated by the 8-mm design, compared to the 1 mm length of the first generation iStent and also the also smaller sized second generation iStent. Nonetheless, they might be comforted by the fact that in the U.S. Pre-market approval (PMA) trial, 97% of clients randomized to Hydrus had successful implantation, 86% on the very first attempt. Time will certainly tell whether it is much better to entail a bigger portion of the canal similar to Hydrus, or if the very focal and stealth iStent strategy is much better. The Hydrus, with its even more extensive expansion coverage can boast fantastic effectiveness data at 2 years. On the other hand, those favoring the more stealth approach might say that much less manipulation might lead to much less scarring long term. For now, based on the data from the FDA tests, both strategies are meaningful as well as a welcome addition to the MIGS portfolio.

Comparison Research Study.
To contrast the efficiency of various MIGS gadgets for lowering intraocular stress (IOP) and also medication in open-angle glaucoma (OAG), a research study was carried out.
Research study participants consisted of 152 eyes from 152 clients aged 45-84 years with OAG, Shaffer angle quality III-IV, Best-corrected visual acuity (BCVA) 20/30 or better, as well as IOP 23-39 mmHg after wash out of all hypotensive drugs. Among the exclusions were eyes with secondary glaucoma aside from pseudo-exfoliative or pigmentary glaucoma, angle closure, eyes that had previous incisional glaucoma surgical procedure done, or eyes with any type of considerable eye pathology aside from glaucoma.
The distinctions were gauged within-group as well as between-group differences in IOP as well as medications at 12 months and complete medical success rates, specified as flexibility from repeat glaucoma surgical treatment, IOP 18 mmHg or much less, as well as no glaucoma medicines. Precaution included the regularity of surgical issues, adjustments in visual acuity, slit lamp findings, and also adverse event rates.
The Study groups were well matched for standard demographics, glaucoma status, drug use and also baseline IOP. Twelve months follow up was completed in 148/152 randomized subjects (97.3%). At 12 months, the Hydrus had a higher rate of full surgical success (p< 0.001) as well as decreased medicine usage (difference = -0.6 medications, p= 0.004). More Hydrus subjects were medication free at twelve months (difference = 22.6% p= 0.0057). Second glaucoma surgical procedure was done in 2 eyes in the 2 iStents team (3.9%) and also in none of the Hydrus eyes. 2 eyes in the Hydrus team as well as 1 in the 2 iStent group had BCVA loss of 2 lines.

Conclusions of the research study were that standalone MIGS in open angle glaucoma with the Hydrus caused a higher surgical success rate and also less medicines compared to the 2 iStent procedures. The two MIGS gadgets have similar safety profiles.

Contraindications.
The Hydrus ® Microstent must not be utilized in clients who have any one of the below listed problems:.
– When the coloured part of the eye (iris) is pushed up versus the drainage pathway or when other material blocks the drainage path (angle closure glaucoma);
– Traumatic glaucoma, malignant glaucoma, or inflammation of the eye tissue (uvea);
– Glaucoma connected with the growth of irregular capillary in the eye (neovascular); or
– Recognizable birth irregularities of the former chamber (AC) angle.

Adverse Reactions.
Usual adverse events included device blockage, worsening of visual field mean deviation by 2 dB or more, as well as BCVA loss of more than 2 Early Treatment Diabetic Retinopathy Study (ETDRS) lines, all of which are no major concern for usage of this device.