Cataract Surgery and MIGS Combined May Not Be Enough to Stop Glaucomatous Damage

Combining cataract surgery with a glaucoma implant can reduce intraocular pressures (IOP) for patients with primary open-angle glaucoma (POAG) by a mean 12.1%, according to a review presented at the Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting held in New Orleans, April 23–27, 2023. However, previous research indicates that IOP needs to be reduced by 20% to stop optic nerve damage.

The presenter performed 2 literature searches regarding concurrent cataract and mild to moderate glaucoma; 1 for cataract surgery and POAG, the other for cataract, POAG, and minimally invasive glaucoma surgery (MIGS). Of the 67 studies initially examined, 11 met the following criteria: POAG subtype only, as well as no emphasis on a prior glaucoma surgery. Investigators analyzed the final 11 papers to discern the safety of techniques, changes to IOP, quantity of glaucoma prescriptions, and cost for procedures.

Specifically, an average IOP drop of 12.1% across 36 months was found with cataract surgery alone, and combined cataract surgery and MIGS  achieved an average IOP decrease of 11.5%.

Notably, one approach was successful in lowering pressure enough to stop optic nerve harm. Cataract surgery combined with ab interno canaloplasty accomplished sufficient decrease in pressure. Other than ab interno canaloplasty, most other paired cataract-MIGS surgeries only provided “minimal IOP reductions.”

“While cataract surgery can somewhat reduce the patient’s IOP, this review found that it is not a singularly effective treatment,” according to researcher Karen Allison, MD, MBA, associate professor of clinical ophthalmology, University of Rochester. The review agreed with earlier analyses showing cataract surgery can result in slightly lower IOP in early stage POAG.Databases searched in the review included the Cochrane Central Register of Controlled Trials, Embase, LILACS, MEDLINE, Scopus, and Web of Science^TM. The investigator noted that further studies on combined cataract surgery and MIGS are underway.