Glaucoma is a chronic disease defined by characteristic optic nerve damage. It is a multi-factorial disease and affects over 40 million people worldwide. Glaucoma is a slowly progressive and irreversible disease and in most cases, causes a painless loss of eyesight. It is, in short, “the silent thief of sight.”

The damage to the optic nerve is commonly caused by a fluid imbalance, or pressure, in the eye, as well as possible alterations in the blood flow to the optic nerve. It is well established that lowering the intraocular pressure can slow the process of the optic nerve damage. The degree of pressure lowering necessary to prevent optic nerve damage is individualized for each person and each optic nerve. The greater the optic nerve damage, the lower the intraocular pressure is needed to achieve stability and prevent further optic nerve damage and further visual field loss.

Previously, topical medications were used as a first-line treatment for glaucoma. In many cases, multiple medications were tried to achieve the desired pressure level. These eye drops can have side effects, causing redness, ocular irritation, and, in some cases, iris darkening. However, recent research, including a significant study known as the LIGHT study, suggests a more effective first-line treatment option: Selective Laser Trabeculoplasty (SLT).

The LIGHT study compared the effectiveness of SLT to that of eye drops as the initial treatment for glaucoma. The results showed that SLT can lower eye pressure as effectively as eye drops. Over time, SLT patients had comparable or even better outcomes than those who started with eye drops. Many patients who begin treatment with SLT either require fewer or no eye drops afterward, leading to fewer daily medications, potentially fewer side effects, and cost savings for patients. SLT can be repeated, and the effects of this procedure typically last 3-5 years.

When glaucoma is well controlled, routine pressure checks every 6 months (and at least twice a year) along with regular optic nerve examinations are essential to monitoring control. Examinations are commonly aided by testing of the nerve fiber layer thickness of the optic nerve, optic nerve photos, and visual field testing. This testing can be done yearly or more frequently based on the level of glaucoma progression.

Unfortunately, there can be difficulties with compliance, cost, and side effects with many of these medications, and laser therapy is commonly substituted as a first-line therapy. Recently, there have been further technological advances for better control of intraocular pressure. Minimally invasive glaucoma surgical procedures, so-called MIGS, involve alterations of the drainage area that are performed inside the eye.

Recent MIGS Advances

iStent and iStent Infinite

The iStent was one of the first MIGS devices to be approved and has paved the way for many advancements in glaucoma treatment. It is a tiny, titanium implant inserted into the eye’s trabecular meshwork to improve the outflow of aqueous humor, thereby lowering intraocular pressure (IOP). The more recent iStent Infinite takes this technology further by utilizing three stents to enhance fluid drainage even more effectively, making it suitable for patients with more advanced glaucoma or those who require significant IOP reduction.

  • iStent: Typically used during cataract surgery for patients with mild to moderate glaucoma.

  • iStent Infinite: Designed for standalone use in more complex glaucoma cases, providing greater IOP reduction through its triple-stent system.

iDose TR

The iDose TR is another groundbreaking MIGS innovation, featuring a sustained-release intraocular implant. This implant continuously delivers travoprost, a common glaucoma medication, directly to the eye over an extended period, reducing the burden of daily eye drops. The iDose TR offers:

  • Consistent Drug Delivery: Ensures steady medication levels, reducing IOP fluctuations.

  • Improved Patient Compliance: Minimizes the need for daily eye drop regimens.

  • Minimally Invasive Implantation: Inserted through a simple, outpatient procedure with minimal recovery time.

OMNI Surgical System

The OMNI Surgical System is another innovative MIGS device that combines two procedures—goniotomy and viscodilation—to enhance aqueous humor outflow. It is designed to address both the trabecular meshwork and the Schlemm’s canal, which are common sites of resistance in glaucomatous eyes.

  • Goniotomy: Involves creating an opening in the trabecular meshwork to improve drainage.

  • Viscodilation: Uses a viscoelastic material to dilate Schlemm’s canal and collector channels, facilitating better fluid outflow.

  • Comprehensive Approach: The OMNI system provides a dual mechanism of action, addressing multiple points of outflow resistance to lower IOP effectively. The procedure can be either done with cataract surgery or as a standalone procedure

Hydrus Microstent by Alcon

The Hydrus Microstent by Alcon is another innovative MIGS device designed to enhance aqueous humor outflow by addressing Schlemm’s canal.

  • Schlemm’s Canal Implantation: The Hydrus Microstent is a tiny, flexible device inserted into Schlemm’s canal to improve fluid drainage and reduce intraocular pressure.

  • Mechanism: It acts as a scaffold, keeping the canal open to allow continuous aqueous outflow.

  • Minimally Invasive: This procedure can be performed during cataract surgery or as a standalone intervention, offering a less invasive option compared to traditional glaucoma surgeries.

  • Long-Term Control: The Hydrus Microstent provides sustained IOP reduction, making it a valuable option for patients with mild to moderate glaucoma.

Advantages of MIGS

  • Minimally Invasive: Reduced risk of complications compared to traditional glaucoma surgeries.

  • Faster Recovery: Shorter recovery times, allowing patients to return to their normal activities quickly.

  • Targeted Treatment: Specific focus on the eye’s natural drainage pathways to enhance outflow and reduce IOP.

Conclusion

MIGS procedures like the iStent, iDose TR, OMNI System, and Hydrus Microstent offer promising advancements in the management of glaucoma. Dr. Angelique Pillar, MD offers all of these MIGS procedures to her patients based on their pressure goals and specific anatomic needs. These technologies provide effective IOP reduction with fewer complications, improved patient compliance, and quicker recovery times compared to traditional surgical methods. As the field of glaucoma treatment continues to evolve, MIGS procedures are likely to play an increasingly central role in achieving better outcomes for patients.

 

This article was originally written on 6/20/2022 by Angelique Pillar, MD and updated on 01/12/2025