Sight Sciences, Inc. announced new data published in the American Journal of Ophthalmology International from a large-scale, comparative, real-world clinical outcomes study using three minimally-invasive glaucoma surgery (MIGS) devices and systems.
Among these technologies: the company’s OMNI Surgical System.
What are the other two technologies?
Referred to as the “most commonly used FDA-approved/cleared ab interno MIGS devices in the U.S.,” these technologies include:
- Hydrus Microstent (Alcon, Inc)
- FDA approved in 2018
- Implantable, flexible, and aqueous device designed to be implanted (ab-interno), bypassing the trabecular meshwork and providing a scaffold for Schlemm’s canal in open-angle glaucoma (OAG).
- iStent inject (Glaukos Corporation)
- FDA approved in 2018
- Indicated for use in conjunction with cataract surgery for intraocular pressure (IOP) reduction in patients with mild-to-moderate primary open-angle glaucoma (POAG).
Note: Both devices have been proven clinically effective in lowering intraocular pressure (IOP).
Hold up a moment. What does ab interno vs. ab externo mean?
Great question!
Ab interno MIGS procedures (i.e. OMNI Surgical System, iStent inject, Hydrus Microstent) are performed through a small corneal incision, allowing access to the angle of the eye from inside the eye.
Meanwhile, ab externo MIGS procedures (i.e. XEN Gel Stent) involve an external incision to access the angle structures from outside the eye.
Gotcha. Now give me a rundown on the OMNI Surgical System.
FDA-cleared in 2021, this system is the first—and still currently only—implant-free, single-use therapeutic glaucoma device indicated for canaloplasty followed by trabeculotomy.Its purpose: to potentially reduce intraocular pressure (IOP) in adults with primary open-angle glaucoma (POAG).
How it works: by opening and potentially restoring flow through the three points of known resistance within the conventional outflow pathway (trabecular meshwork, Schlemm’s canal, and collector channels) of the eye via a single, clear corneal microincision.
Didn’t we just hear clinical news on this?
Indeed! At the 2024 American Society of Cataract and Refractive Surgery (ASCRS) annual meeting earlier this month, the company reported new long-term data from an extension study of the 12-month GEMINI study (NCT03861169).
The study confirmed prior data on the effectiveness of OMNI (with canaloplasty and trabeculotomy) combined with cataract surgery for lowering IOP and medication adherence in OAG patients.
Read our coverage here.
Gotcha. Now talk about this comparative study.
Investigators of this retrospective, observational study used the the American Academy of Ophthalmology’s Intelligent Research in Sight (IRIS) Registry to evaluate long-term, 2-year post-surgical outcomes of POAG patients treated with three different MIGS devices (see above) combined with cataract surgery and with cataract surgery alone.
The study period: 24 months (July 1, 2016 – June 30, 2020)
I need more patient details.
A total of 77,391 OAG patients (109,745 eyes) were included in the study cohorts.
Of that, 6,632 patients (9,000 eyes) underwent MIGS in combo with cataract surgery; the remaining 70,759 patients (91%) received cataract surgery alone.
Note: Similar baseline characteristics in IOP and mean number of IOP-lowering medications were noted among these patients, who were separated into four cohorts (one per each MIGS device and one for cataract surgery alone).
So there were four cohorts in total?
Yup! These included:
- OMNI cohort
- n = 428 (541 eyes)
- Hydrus Microstent cohort
- n = 1,435 (1,901 eyes)
- iStent inject cohort
- n = 4,769 (6,558 eyes)
- Cataract surgery cohort
- n = 70,759 (100,745 eyes)
Then (not to make this any more confusing), the total participant population was divided into two subgroups based on their baseline (pre-surgical) IOP):
- Subgroup 1: >18 mmHg
- Subgroup 2: ≤ 18 mmHg
And what was measured?
Primary outcomes included change in IOP and the number of IOP-lowering medication classes used over time (from baseline to 24 months post-op).
Outcome stratification was based on baseline IOP measurements (high baseline: >18 mmHg or low baseline: ≤18 mmHg) and disease severity (mild, moderate, or severe).
Now the findings.
Starting with the OMNI cohort, high-baseline IOP patients at 24 months presented with the greatest numerical reduction in IOP (-6.64 mmHg [30%]) and medication use (-1.34).
For low-baseline IOP patients, they also presented with the greatest numerical reduction in IOP (-0.47 mmHg; 3%) as well as a statistically significantly greater mean medication use reduction (-1.42) vs all other treatment groups.
And the other cohort findings?
- Hydrus Microstent cohort
- High-baseline IOP patients presented with a -5.71 mmHg (25%) IOP reduction and a medication use reduction of -1.20.
- Low-baseline IOP patients presented with no IOP reduction (+0.03 mmHg [0%]) and a medication use reduction of -1.18.
- iStent inject cohort
- High-baseline IOP patients presented with a -4.96 mmHg (22%) IOP reduction and a medication use reduction of -0.86.
- Low-baseline IOP patients presented with a -0.17 mmHg (1%) IOP reduction and a medication use reduction of -0.95.
- Cataract-surgery alone cohort
- High-baseline IOP patients presented with a -5.55 mmHg (24%) IOP reduction and a medication use reduction of -0.67.
- Low-baseline IOP patients presented with a -0.07 mmHg (0%) IOP reduction and a medication use reduction of -0.65.
So what does all this mean?
Based on the data, the study authors noted that a sustained and significant IOP reduction was evident across all four cohorts over the 24-month observational period.
However, “the largest numerical reduction (was) found for patients in the OMNI cohort,” they wrote.
Go on…
More generally—based on stratification according to baseline IOP—participants with higher baseline IOP were found to demonstrate “numerically greater reductions in IOP over 24 months, most notably for patients who were treated with OMNI,” the authors stated.
These results are also similar to prior data on the OMNI Surgical System, they noted.