With a favorable safety profile and ability to be easily incorporated into practices, minimally invasive glaucoma surgery (MIGS) has been welcomed by ophthalmologists. However, MIGS procedures currently are approved by the US Food and Drug Administration (FDA) to be performed only in conjunction with cataract surgery. Studies that can substantiate the benefits of MIGS as a stand-alone procedure may help MIGS gain wider approval.
Thankfully, the recently published ROMEO study has arrived at such findings. Investigators behind this multicenter, retrospective study assessed the intraocular pressure (IOP) lowering effect of canaloplasty and trabeculotomy with the OMNI System (Sight Sciences, Inc, Menlo Park, California) in 48 pseudophakic patients with open-angle glaucoma. Patients were stratified in equal numbers into two groups based on their baseline IOP (> 18 mm Hg or ≤ 18 mm Hg). Primary success was defined as IOP ≤ 18 mm Hg and ≥ 6 mm Hg or a 20% reduction from preoperative IOP with same or fewer number of ocular hypotensive medications and no additional IOP-lowering surgery or laser.
At 12 months, the overall success rate in both groups was 70.8%. The median percentage change from preoperative IOP was approximately 26%. Almost 50% of patients in both groups were able to reduce their medication usage by one drop. The adverse effects were mild and not visually significant. Five patients (10.4%) required another surgical or laser intervention, which occurred at a mean of 252 days.
Though this study drew from a small cohort, it nonetheless provides evidence of the clinically important outcomes that MIGS can produce.
I have had the opportunity of offering stand-alone MIGS procedures to patients, including to those who are pseudophakic. In many cases, by doing so I was able to postpone or avoid more-invasive surgery, as well as achieve considerable reductions in IOP and reduced medication burden.
Often, a patient is on maximally tolerated medications and still needs a slightly lower IOP. If the only available options are a glaucoma drainage device or trabeculectomy, an ophthalmologist may opt to observe the patient for slightly longer on current treatment due to the higher risk of adverse events with these procedures. This is often detrimental to the patient, as the glaucoma continues to progress, until finally the ophthalmologist is compelled to perform a trabeculectomy or tube shunt. In such cases, MIGS may help achieve the IOP-lowering goal sooner with less complications and avoid any further vision loss.
Conversely, a patient who is on minimal medications and has well-controlled IOP may have difficulty with compliance or intolerance to drops. MIGS is also a more appealing option because it produces fewer complications.
The ROMEO study's finding that OMNI as a stand-alone procedure is efficacious in decreasing IOP and reducing medication use may indeed make it more widely applicable to many patients. We eagerly await the results of the other ongoing trials assessing OMNI as a stand-alone procedure.
Several new MIGS procedures have been made available in the past decade. We need to establish how to define the success of any one procedure, and to compare it not only with cataract surgery alone but also with other MIGS. Once more stand-alone studies and comparative MIGS studies are conducted, it will help establish the place of such devices as OMNI in the treatment paradigm. We hope MIGS will also gain FDA approval for broader use so even more patients will be able to benefit from this surgery.
Shuchi B. Patel, MD, is director of glaucoma services in the department of ophthalmology at West Palm Beach VA Medical Center in Florida. She explores the ever-changing glaucoma space for Medscape, including advances in diagnostics and treatments.
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Cite this: Shuchi B. Patel. The Case for Stand-alone MIGS Gets Stronger - Medscape - Mar 09, 2021.