Introduction
The OMNI Surgical System (Sight Sciences) provides the opportunity for clinicians to perform a MIGS procedure that combines three mechanisms—ab-interno canaloplasty, distal outflow dilation, and trabeculotomy—into a single surgery. It can address and alleviate the three sources of outflow resistance in the conventional outflow pathway, which, from proximal to distal, include the trabecular meshwork, Schlemm’s canal, and collector channels. The procedure leaves no implant behind.
The OMNI procedure is versatile. The trabeculotomy and canaloplasty procedures can be performed sequentially in a single surgery, allowing the treatment of up to 360º of Schlemm’s canal. Alternatively, canaloplasty can be performed on its own. OMNI can also be performed in combination with cataract surgery or as a standalone procedure.
The handheld instrument (Figure) includes a cannula, a microcatheter for viscodilation and cutting tissue, an internal reservoir for OVD, and a finger wheel for advancing the microcatheter into the Schlemm’s canal. Most surgeons report a short learning curve with the device.
Figure. The OMNI Surgical System.
The following dialogue from three surgeons who have amassed significant early experience with the OMNI Surgical System helps substantiate the value of the implant-free procedure in everyday clinical practice. Each panelist also provides a case study to illustrate the different ways in which the OMNI can be used.
How long have you been using the OMNI Surgical System in your practice?
Dan Lindfield, BM, PGCME, FRCOphth: I was fortunate enough to be one of the first surgeons in the United Kingdom to use OMNI. I now have 2 years of experience with the procedure, and at the time of the interview performed just shy of 100 cases. Most of these cases were for patients with mild to moderate open-angle glaucoma. I have performed OMNI both as a combined procedure with phacoemulsification and as a standalone procedure. Most often, I combine it with cataract surgery. The results patients have had thus far have exceeded what I can achieve with other devices that treat only the trabecular meshwork with a similar safety profile.
Andrew Tatham, MD, MBA, FRCOphth, FEBO, CertLRS: I’ve been using the OMNI Surgical System for about 18 months. Before then, I used a range of Schlemm’s canal–based MIGS procedures to remove trabecular meshwork and increase aqueous humor outflow into the aqueous veins. What attracted me to OMNI, however, is that it’s an implant-free option with three mechanisms of action (ab-interno canaloplasty, distal outflow dilation, and trabeculotomy). I like that it addresses the three sources of outflow resistance in the conventional outflow pathway and that I can complete two IOP-lowering procedures in one surgery.
Francesco Stringa, MD, MCOphth, FEBOS-GL: Viscocanaloplasty and trabeculotomy are two well-established procedures for the treatment of open-angle glaucoma. They are part of the MIGS universe. I like that OMNI combines both into a single implant-free procedure. I started using OMNI in the beginning of 2022. I appreciate that I can treat different degrees of the trabecular meshwork and that I can combine two different procedures into one surgery.
What do you see as the key benefits of the OMNI system?
Dr. Lindfield: For me, the key benefit is that I see and feel when I’m in the right place in Schlemm’s canal. This gives me the confidence that, as the microcatheter slides into the canal, I am treating the target tissue that I want to treat. I think this differentiates OMNI from other devices that don’t provide physical or visual feedback. Furthermore, I like that the device allows me to adjust the extent of the treatment that I can achieve with one device by treating either 180º or 360º of Schlemm’s canal and that I can either spare or cut the trabecular meshwork. I regularly treat 360º of Schlemm’s canal and trabecular meshwork, and the beauty of the OMNI Surgical System is it does so without leaving a device behind in the eye.
Dr. Tatham: Compared to other MIGS procedures, there are several advantages with OMNI. The first is that no device is left in the eye. Second, it can be performed as a standalone treatment or combined with cataract surgery, and it is customizable to the patient. Third, I like that I can choose how many degrees to treat with canaloplasty alone or combined with trabeculotomy, and I can do so depending on the patient’s needs.
Dr. Stringa: I agree with Drs. Lindfield and Tatham that a main advantage is that I can choose how many degrees of treatment I want to perform. It’s also extremely beneficial that two different types of procedures can be performed with the same device. I can plan whether I want to treat 360º of Schlemm’s canal, perform a viscocanaloplasty alone, or plan a combined viscocanaloplasty/trabeculotomy procedure.
How would you describe the ease of use of OMNI?
Dr. Lindfield: My learning curve with OMNI was similar to other MIGS procedures I have experience with. Additionally, there are translatable skills. I think for those who have used a trabecular microbypass device, OMNI would be a perfect fit for their practice. The handpiece is nicely designed, and I find that it slides into Schlemm’s canal neatly and nicely. I tilt the handpiece upward about 30º, as a flat position can lead to the device diving down toward the iris. The tactile and visual feedback that OMNI provides helps me know I’m treating the right area. I don’t always feel that with other devices.
Once inserted in Schlemm’s canal, it only takes a few cases to get used to how to advance the OMNI device smoothly and carefully. If the catheter meets resistance momentarily, I retract the wheel slightly. It should then slide into Schlemm’s canal easily without resistance.
Dr. Tatham: I position the handpiece similarly to Dr. Lindfield. I angle the device at about 20º, and I aim for the roof of Schlemm’s canal so that the microcatheter brushes across the roof and passes through the canal without resistance. It took some practice for me to balance movement of the device’s wheel to retract the microcatheter in a controlled manner during trabeculectomy. I learned that shortening the catheter slightly and pausing between movements ensures successful completion of the maneuver.
Overall, I find the OMNI Surgical System fairly easy to use. The length of the learning curve depends on the clinician’s previous exposure to Schlemm’s canal–based MIGS procedures. As with any MIGS procedure, it’s important to have a good grasp of intraoperative gonioscopy to ensure good visualization.
The ideal position for the patient’s head is to be turned away from the surgeon about 30º to 40º. The microscope should be positioned toward the surgeon by a similar number of degrees. Consider practicing these positions in patients who may not even need a MIGS procedure. Once these basics have been grasped, I think performing OMNI is just like performing other canal-based MIGS procedures.
Dr. Stringa: The OMNI procedure requires approximately 10 to 20 initial cases to become confident and efficient with the device. I agree with what Drs. Lindfield and Tatham have shared. Positioning of both the patient and microscope and being comfortable with intraoperative gonioscopy are extremely important for the procedure, as is having a clear view of the trabecular meshwork. In fact, placing the catheter correctly in Schlemm’s canal as soon as the trabecular meshwork is engaged by the cannula tip is the key for a successful procedure. With these things mastered, the safety profile with OMNI is comparable to other ab-interno MIGS devices.
In your opinion, what patient groups make good candidates for OMNI?
Dr. Lindfield: The ideal candidate for OMNI is someone with mild to moderate open-angle glaucoma. Consider starting with patients who present with pigmented angles because it is easier to identify landmarks than in eyes with pale angles. Additionally, look to perform OMNI first as a combined procedure with phacoemulsification or in pseudophakic patients to reduce concerns about touching the crystalline lens.
Dr. Tatham: Because OMNI can be used as a standalone procedure or combined with cataract surgery, it can be a good option for a broad range of scenarios (Editor’s note: the sidebars by Drs. Lindfield, Tatham, and Stringa include examples of scenarios for which they chose the OMNI Surgical System). Personally, I think the procedure is a good option for patients with concomitant cataract and glaucoma who wish to potentially reduce the medication burden. These patients often also have ocular surface disease. Compliance is a problem for patients on multiple medications, and their quality of life improves drastically after OMNI surgery when the medication burden is reduced. Another scenario in which I find OMNI useful is in phakic patients who have suboptimal IOP control. In these patients, I often perform OMNI as a standalone procedure.
In my early experience with OMNI, I selected cases that I knew I would have a good view of the angle. This helped me learn how to place the microcatheter in the correct location and move it along the correct path. The bright blue color of the microcatheter helps with tracking its course, especially over the first 60º to 70º.
Dr. Stringa: As mentioned previously, the views of the angle and trabecular meshwork is important. Therefore, ideal candidates for the OMNI procedure are those with open angles and, particularly for the first cases, those with a well-defined angle anatomy. In terms of glaucoma stage, good candidates are those with early to moderate glaucoma and a target IOP in the mid to low teens.
IMPORTANT PRODUCT INFORMATION:
INDICATIONS FOR USE: The OMNI® Surgical System is indicated for the catheterization and transluminal viscodilation of Schlemm’s canal and the cutting of trabecular meshwork to reduce intraocular pressure in adult patients with open-angle glaucoma. For important safety information including contraindications, warnings, precautions and adverse events, please visit omnisurgical.com
Surgeons are paid consultants of Sight Sciences
This information is intended solely for the use of ophthalmic clinicians - Patients should contact their eyecare professional.
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© 2023 Sight Sciences, Inc 6/23 OM-2915-OUS.v1 CE2797
