Cataract and glaucoma frequently occur together — both are diseases of ageing, and both are common in patients over 60. When they coexist, the surgical plan changes. Decisions are no longer just about restoring vision; they must also protect the optic nerve from further damage and, ideally, reduce the burden of glaucoma drops at the same time. At Suraj Eye Institute, every glaucoma patient considering cataract surgery is jointly assessed by our cataract and glaucoma teams to choose the right operation for that individual eye.

Why the Two Diseases Interact

Cataract and glaucoma influence each other in three important ways:

• Cataract obscures glaucoma assessment. A dense cataract can produce false visual field defects and degraded OCT scans, masking real glaucoma progression. After cataract surgery, fields and OCTs become reliable again.
• Cataract surgery itself lowers IOP. Removing the bulky natural lens deepens the anterior chamber and opens the drainage angle. The IOP-lowering effect is dramatic in narrow-angle eyes and modest but real in open-angle glaucoma.
• Glaucoma surgery can accelerate cataract. Trabeculectomy and tube surgery often hasten cataract formation. Combining the two operations avoids that problem.

The Three Surgical Options

1. Phacoemulsification Alone

Suitable when:

• Glaucoma is mild and well controlled on minimal medication
• Optic nerve damage is limited and visual fields are stable
• Angle closure or narrow angles are present (lens removal opens the angle and is often sufficient by itself)

The phaco itself is the same as a routine cataract surgery, but the surgeon takes extra care to keep IOP stable, protect the corneal endothelium and avoid intra-operative pressure spikes that could damage an already-compromised optic nerve.

2. Phaco + MIGS (GATT or KDB Goniotomy)

GATT (gonioscopy-assisted transluminal trabeculotomy) and KDB (Kahook Dual Blade) goniotomy are minimally invasive glaucoma procedures (MIGS) performed through the same corneal incision as the phaco. They reopen the eye’s natural drainage pathway by removing or cleaving the trabecular meshwork.

Suitable when:

• Mild-to-moderate open-angle glaucoma — primary, pseudoexfoliative or pigmentary
• Patient on 1–3 glaucoma drops who would benefit from drop reduction
• Eye not yet at target IOP on current treatment

MIGS adds only a few minutes to phaco, has minimal added risk, and typically reduces IOP and the number of glaucoma drops without creating a filtering bleb.

3. Phaco + Trabeculectomy

A combined “filtering” operation — phaco for the cataract, trabeculectomy for the glaucoma. Trabeculectomy creates a controlled drainage channel under the conjunctiva, lowering IOP into the low-teens. It remains the most effective IOP-lowering operation available.

Suitable when:

• Moderate-to-advanced glaucoma with significant optic nerve and field damage
• IOP not reachable to target with maximum medical therapy or MIGS
• Pseudoexfoliation, neovascular or other aggressive glaucomas
• Patient unable to comply with multiple drops

The combined operation is longer and recovery slower than phaco alone or phaco-MIGS, but it offers the strongest pressure reduction and the highest chance of being drop-free afterwards.

Pre-operative Assessment

Before any combined operation we ensure:

• Anterion biometry for accurate IOL power calculation — particularly important in eyes with shallow anterior chambers or pseudoexfoliation
• Macular OCT to rule out macular disease that would limit visual recovery
• RNFL / GCL OCT and visual fields to document the current stage of glaucoma damage
• Gonioscopy to determine the angle status and confirm suitability for MIGS
• Endothelial cell count in eyes with previous angle-closure attacks or pseudoexfoliation

IOL Choice in Glaucoma Patients

Premium IOLs (multifocal, trifocal, EDOF) require a healthy retina and intact contrast sensitivity. Glaucoma damages both. As a rule:

• Mild glaucoma, no field damage: EDOF or trifocal IOL is reasonable if patient highly motivated
• Moderate glaucoma: high-quality monofocal IOL preferred; EDOF in selected motivated patients
• Advanced glaucoma: monofocal IOL almost always — split-light optics will compromise an already-compromised visual field
• Toric monofocal IOL: a good option for glaucoma patients with astigmatism — it gives spectacle-free distance vision without the contrast cost of multifocal optics

Recovery and Post-operative Care

Post-op care after a combined operation is more involved than after phaco alone:

• More frequent visits in the first 4–6 weeks to titrate IOP, manage filtering blebs (after trabeculectomy) and adjust drops
• Steroid drops are tapered carefully; in some glaucoma patients steroids cause IOP rise themselves
• Fields and OCT are repeated 2–3 months after surgery to establish a new clean baseline
• Long-term follow-up with the glaucoma team continues — combined surgery treats the disease but does not cure it

Frequently Asked Questions