Cataract glaucoma surgery sits at a practical crossroads: one procedure can clear the lens while another aims to reduce intraocular pressure or medication burden. The idea sounds efficient, like pairing sharper sports eyewear with better tracking equipment, but the evidence is more conditional than simple. Outcomes vary by glaucoma type, baseline pressure, cataract severity, prior procedures, and whether the surgeon chooses a combined or staged plan.
The clearest message from recent studies is not that one approach wins for every eye. Instead, combined surgery can reduce visits and anesthesia exposure, while staged surgery or standalone glaucoma surgery may reach lower pressure targets in selected uncontrolled cases. For athletes, coaches, and performance staff who think in systems, the analogy is familiar: a new visor or sensor helps only if it fits the player, the field conditions, and the tactical goal.
Cataract Glaucoma Surgery Evidence By Procedure Type
Cataract Glaucoma Surgery In Mild To Moderate POAG
The 36-month GEMINI extension is one of the cleaner longer-term data points for mild-to-moderate primary open-angle glaucoma with cataract. In that prospective U.S. study across 11 practices, OMNI canaloplasty and trabeculotomy were combined with phacoemulsification. Unmedicated mean diurnal IOP was about 23.1 mmHg at baseline and measured about 16.3 to 16.7 mmHg during months 24 through 36; medications dropped from 1.7 to about 0.3 to 0.4, and roughly 74% of eyes were medication-free at 36 months, according to the GEMINI 36-month report.
That evidence supports the use of canal-based combined procedures in a defined population, not in every patient with advanced disease. A canal-based operation depends on outflow pathway function, and its pressure-lowering ceiling may not match the needs of eyes requiring very low target pressures. This is where case selection becomes the real technology: imaging, angle assessment, optic nerve status, and pressure history matter as much as the surgical device.
Filtering And Tube Procedures In Higher-Risk Eyes
For more advanced or uncontrolled glaucoma, older filtering strategies still shape decision-making. A February 2026 retrospective cohort of 249 eyes compared phaco-trabeculectomy with phaco plus Ahmed glaucoma valve over follow-up extending up to 6 years. Surgical success, defined as IOP 6 to 21 mmHg with or without medications, was 59.9% in the phaco-trabeculectomy group versus 40.1% in the phaco-Ahmed group. Both groups improved visual acuity, while phaco-trabeculectomy needed fewer long-term glaucoma medications and had fewer complications in that cohort.
Those numbers do not prove that phaco-trabeculectomy is universally preferable. Retrospective designs can reflect selection patterns: surgeons may choose a tube for eyes with different risks than eyes selected for trabeculectomy. Still, the finding is clinically useful because it shows how combined cataract and glaucoma procedures can diverge once disease severity and surgical risk rise.
Why Combined Surgery Can Help And Where It Falls Short
Pressure Reduction Is Not The Only Endpoint
The appeal of cataract glaucoma surgery is partly logistical. One operating-room event may address clouded vision and reduce IOP or medication dependence. In primary angle-closure glaucoma with cataract, a multicenter prospective study of phacoemulsification plus goniosynechialysis reported mean IOP reduction from 22.9 ± 10.2 to 14.0 ± 3.1 mmHg at 12 months among eyes with follow-up data. Medications fell from 2.08 ± 1.23 to 0.14 ± 0.52; complete success was 80.6%, qualified success was 88.3%, complications occurred in 17%, and 2.1% required later glaucoma surgery.
This is meaningful because angle-closure eyes can gain both optical and anatomic benefit from cataract extraction, yet the study still reported complications and a small need for further surgery. That pattern fits the broader evidence: synergy is real in selected eyes, but it is not a guarantee of surgical finality.
Medication Burden And Device Selection
Registry and meta-analytic findings show a more modest but relevant effect for MIGS combined with cataract surgery in open-angle glaucoma. In a large IRIS Registry observational analysis from 2017 to 2022, eyes with baseline IOP above 18 mmHg had IOP reductions of about 4.96 to 6.64 mmHg at 24 months depending on the device, with medication reductions of about 0.86 to 1.34 classes. Eyes starting at 18 mmHg or lower showed significant medication reduction without IOP worsening.
A meta-analysis of seven studies through November 2024 found that MIGS plus cataract surgery reduced IOP by about 1.58 mmHg more than cataract surgery alone and reduced medications by about 0.79 classes. Heterogeneity was high, so the average effect should not be treated as a fixed expectation for an individual patient. Readers tracking outflow-based strategies can compare this cautious evidence framing with uveoscleral outflow evidence, where mechanism and patient selection also shape interpretation.
Staged Versus Combined Decisions In Complex Eyes

Staging May Reach Lower Final Pressure
Combined procedures are efficient, but staged surgery may be stronger in some uncontrolled cases. A single-center observational study with 72 eyes and 4-year follow-up compared phacoemulsification first followed by trabeculectomy at least 6 months later against combined phacotrabeculectomy. The staged group reached a significantly lower final IOP: 10.9 ± 3.6 mmHg versus 14.8 ± 6.2 mmHg. It also had higher long-term success rates by multiple criteria, fewer medications, and fewer postoperative interventions.
That result matches a common surgical principle: separating the lens operation from the filtering operation may reduce competing wound-healing or inflammation variables. Yet staging can require two surgical episodes, two recovery periods, and more patient burden. For a working adult or athlete managing training, travel, and visual demands, that tradeoff is not trivial.
Cataract Risk And Surveillance After Glaucoma Surgery
A 2026 UK Biobank cross-sectional observational study reported that glaucoma was associated with higher odds of cataract, with an adjusted odds ratio of 3.09, and glaucoma surgery had the highest odds for co-existing cataract, with an odds ratio of 12.0, as reported in the UK Biobank analysis. Association does not prove that glaucoma or its treatment directly caused the cataract in every case, but the signal supports careful lens surveillance in patients who have glaucoma surgery.
This matters for timing. If cataract is mild but glaucoma is severe, the eye may need glaucoma-first surgery. If the cataract is visually limiting and pressure is controlled, cataract surgery alone or cataract plus a lower-risk glaucoma procedure may be considered. Guidelines summarized in the research record also emphasize that combined filtering plus phacoemulsification can lower pressure more than phacoemulsification alone, yet filtering surgery alone may have higher success than combined filtering surgery in some settings.
Implications For Cataract Glaucoma Surgery In Practice
Matching The Tool To The Target Pressure
The practical implication is that cataract glaucoma surgery should be judged against a specific target, not against a generic promise. Mild-to-moderate open-angle glaucoma with medication burden may fit canal-based MIGS plus cataract extraction. Angle-closure disease with synechiae may fit lens extraction plus goniosynechialysis in selected anatomy. Advanced glaucoma needing very low IOP may still require trabeculectomy, tube surgery, or a staged plan.
Pseudoexfoliation glaucoma shows why caution is needed. In a study comparing cataract surgery alone with phacotrabeculectomy over at least 3 years, both groups had about 27% to 40% IOP reduction, complete success rates were not statistically different, and visual acuity gains were similar. Complications were slightly higher with combined surgery. For some eyes, adding a glaucoma procedure may not add enough benefit to justify the extra risk.
Evidence, Equipment, And Patient-Specific Planning
Good sports equipment works when the specifications fit the athlete. Eye surgery is less forgiving. A pressure target, medication tolerance, angle status, optic nerve damage, cataract density, and follow-up capacity all influence the plan. Readers who compare health-device evidence with other applied-science sectors may recognize the same caution used by Illinois Energy: performance claims need context, scale, and limits to be properly evaluated.
For complex cases, the evidence supports shared planning between the patient and ophthalmologist rather than a one-size procedure. Combined surgery can be efficient and effective, especially in selected open-angle and angle-closure eyes. Staged surgery can be preferable where lower pressure is needed or where the glaucoma operation should be isolated from cataract-surgery variables. Standalone cataract surgery may be enough in some pseudoexfoliation or controlled glaucoma cases, but that decision depends on measured risk rather than convenience alone.
The best reading of the evidence is restrained: cataract glaucoma surgery is a useful strategy, not a universal upgrade. Its value is highest when the chosen procedure matches disease mechanism, target pressure, and tolerance for risk.


















