The case for standalone micro-invasive glaucoma surgery: rethinking the role of surgery in the glaucoma treatment paradigm

Abstract

Purpose of reviewTo highlight progress in glaucoma therapy challenging the traditional medication-first approach and present evidence supporting early standalone surgery in the era of micro-invasive glaucoma surgery (MIGS).Recent findingsMedical therapy is limited by well documented poor adherence that compromises the quality of intraocular pressure reduction. Results from modern clinical trials demonstrate advantages of selective laser trabeculoplasty and MIGS procedures in terms of both IOP control and progression risk.SummaryThe MIGS options for pseudophakic or precataractous patients are limited by regulatory rules that require the performance of some procedures only at the time of cataract surgery. These include the iStent/iStent Inject and the Hydrus implants. Nonbleb-forming procedures currently available for standalone use in eyes with mild–moderate primary open-angle glaucoma include gonioscopy-assisted transluminal trabeculotomy (which lowers IOP by 28-61% and medication use by 38–73% in various studies), trabecular ablation with the Trabectome (23–39% and 21–43%, respectively), excisional goniotomy with the Kahook Dual Blade (15–36% and 15–40%, respectively), ab interno canaloplasty (35% and 57%, respectively), and combined canaloplasty and trabeculotomy using the OMNI system (39–40% and 64–73%, respectively). For patients who would benefit from early standalone surgery, these procedures offer meaningful reductions in both IOP and medication burden.

Challenging the "Topical Medications-First” Approach to Glaucoma: A Treatment Paradigm in Evolution

“…Designed as safer and more physiologic alternatives to traditional trabeculectomy and tube-shunt procedures, these procedures collectively offer more modest IOP reductions for patients who would benefit from surgery but whose treatment goals may not justify the risk of traditional surgery [ 153 – 155 ]. Accordingly, the notion of employing surgery earlier in the treatment cascade, rather than saving it as a last resort, has been raised [ 156 , 157 ]. Given that the trabecular meshwork is the primary site of histopathological changes related to elevated IOP [ 158 ], targeting the meshwork early in the disease process is a logical approach, and several studies have suggested a beneficial disease-modifying effect of early intervention that may not be fully explained by IOP reduction alone [ 159 , 160 ].…”

“…Various MIGS procedures combined with cataract surgery have been shown to be cost-effective compared to cataract surgery alone [ 128 , 129 , 161 ], and also compared to topical medication therapy. Relatedly, there have been calls to unbundle some glaucoma procedures from the often-required concomitant cataract surgery and allow them as standalone procedures so patients who might benefit have more than a one-moment-in-time opportunity to receive them at the time of cataract surgery [ 156 ].…”

Alternatives to Topical Glaucoma Medication for Glaucoma Management

“… 132 , 133 Depending on country and clinical context, some procedures are performed as standalone therapy, while others are performed at the time of cataract surgery. 134 …”

“…Many pseudophakic patients would benefit from standalone MIGS surgery, and the options in this setting are limited. 134 …”

Ab Interno Canaloplasty and Trabeculotomy Outcomes for Mild, Moderate, and Advanced Open-Angle Glaucoma: A ROMEO Analysis

“… 1 However, MIGS usage has evolved with a more expansive role in the current treatment paradigm; the possibility for earlier surgical intervention is a common theme in discussions of MIGS. 2 , 3 Concomitant use with cataract surgery has made glaucoma surgery an accepted option for patients with very mild disease, while demonstrated effectiveness for some MIGS has also been shown for standalone use in refractory glaucoma. 4–6 But what about advanced glaucoma?…”