Cataract Surgery as a Glaucoma Treatment
Removing the eye's natural lens does more than clear a cataract — in many patients, it meaningfully widens the drainage angle and lowers eye pressure on its own.
How Cataract Surgery Helps Glaucoma
The eye's natural lens gradually thickens with age, crowding the space in front of it and, in many people, narrowing the drainage angle. Removing that lens during standard cataract surgery (phacoemulsification) and replacing it with a much thinner artificial lens implant creates more room in the front of the eye, widening and deepening the drainage angle. This anatomic change can produce a real reduction in eye pressure, entirely apart from any glaucoma device added during the same surgery.
Especially Important for Narrow Angles & Angle Closure
This effect is most pronounced, and most clinically important, in eyes with narrow angles or angle-closure glaucoma, where lens thickness is often a central part of the underlying problem. The EAGLE trial, a randomized controlled trial published in The Lancet in 2016, found that early clear lens extraction produced better long-term eye pressure control and was more cost-effective than laser peripheral iridotomy in patients with primary angle-closure glaucoma and elevated eye pressure.1 For the right patients, this has shifted cataract or clear lens surgery from an incidental afterthought to a genuine, evidence-based primary treatment option.
Benefit in Open-Angle Glaucoma
In open-angle glaucoma, cataract surgery alone tends to produce a smaller, though still real, reduction in eye pressure, likely through a modest widening of the angle and improved outflow dynamics. It is not typically relied upon as a stand-alone glaucoma treatment in open-angle disease the way it can be in angle-closure glaucoma, but it is a meaningful and welcome side benefit whenever cataract surgery is otherwise needed.
Combining With MIGS
Because cataract surgery already involves a small corneal incision, it is an ideal opportunity to add a MIGS device — such as iStent, Hydrus, or ab-interno canaloplasty — in the same operation, for very little additional time or risk. This combined approach often achieves meaningfully better pressure control and medication reduction than cataract surgery alone. See our MIGS Surgery page for details on each device.
Risks & Considerations
Cataract surgery carries its own standard set of risks (infection, inflammation, retinal detachment, and others), which your surgeon will review in detail as part of routine cataract surgery counseling, separate from any glaucoma-specific risk. In glaucomatous eyes, we also pay close attention to the health of the corneal endothelium and the stability of the drainage angle when planning surgical technique.
References
- Azuara-Blanco A, Burr J, Ramsay C, et al. Effectiveness of early lens extraction for the treatment of primary angle-closure glaucoma (EAGLE): a randomised controlled trial. Lancet. 2016;388(10052):1389-1397.
Frequently Asked Questions
Can cataract surgery treat my glaucoma even without a MIGS device?
Yes, to a degree. Cataract surgery alone widens and deepens the drainage angle by removing the natural lens, which is thicker than the artificial lens implant that replaces it, and this can produce a real, though usually modest, reduction in eye pressure — more pronounced in narrow-angle and angle-closure glaucoma than in open-angle glaucoma.
Should I have cataract surgery before or instead of laser iridotomy?
For patients with narrow angles and a visually significant cataract, the EAGLE trial found that early lens extraction outperformed laser iridotomy for pressure control and was more cost-effective, which we factor into this conversation for the right candidates.
Can a MIGS device be added at the same time?
Yes, and it's extremely common. Adding a MIGS device such as iStent, Hydrus, or ab-interno canaloplasty during cataract surgery adds relatively little time or risk while further improving pressure control beyond what lens removal alone provides.
Will cataract surgery cure my glaucoma?
No. Cataract surgery can meaningfully help with eye pressure, especially in narrow-angle and angle-closure glaucoma, but it doesn't reverse existing optic nerve damage and typically isn't a complete glaucoma treatment on its own for most patients.
See a glaucoma specialist. Dr. Robert Gunzenhauser is Harvard-educated and UCLA fellowship-trained in glaucoma, providing expert diagnosis and treatment for Cataract Surgery for Glaucoma at Inland Glaucoma Center in Upland, CA.