Patient guide · Glaucoma surgery
Deep sclerectomy — a non-penetrating operation for open-angle glaucoma.
A clinically reviewed guide to non-penetrating deep sclerectomy: how it lowers eye pressure by preserving the trabeculo-Descemet’s membrane, when it is preferred over trabeculectomy, and what the recovery really looks like.
6 min read · Last reviewed 2026-07-30 · Next review 2027-07-30
Why patients choose us
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A glaucoma-subspecialty ophthalmologist
Not a generalist and not a training list. A named consultant ophthalmologist with a fellowship interest in glaucoma surgery — and the caseload to match.
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The non-penetrating option, honestly discussed
Deep sclerectomy is not for every eye. We say when it beats trabeculectomy, when a MIGS device fits better, and when medical therapy still has room to run.
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Independent, and free
We are paid by no clinic, so the recommendation is impartial and costs you nothing.
The problem
The right surgeon, the right technique, at the right moment.
Glaucoma surgery is not a single decision — it is a sequence. When to move from drops to laser, laser to filtration, and which filtration. Deep sclerectomy has a real place, and a real ceiling; we help you see both.
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Not sure it is time?
A field test, an OCT and an honest gonioscopy usually settle it. We can convene the workup before you commit to surgery.
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Worried about hypotony?
Deep sclerectomy exists precisely to reduce that risk versus a classical trabeculectomy — the reason many surgeons prefer it in younger and myopic eyes.
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Want it done properly?
A named glaucoma-subspecialty ophthalmologist, a dedicated theatre, and the same surgeon for postoperative needling and YAG goniopuncture.
The journey
From workup to long-term monitoring — what happens, in order.
One surgeon from workup to twelve-month review — including any needling and, if needed, YAG goniopuncture in clinic.
Phase 1 · Before surgery
Workup and planning
Phase 2 · On the day
A morning in theatre
Phase 3 · After
Three-month intensive follow-up
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Before
You tell us about your glaucoma
A short, confidential form. Current drops, IOP history, any previous laser or surgery, and how the visual field is behaving.
- 02
Before
Workup with your surgeon
Visual field, OCT of the retinal nerve fibre layer, gonioscopy of the drainage angle, corneal thickness — the numbers that set the target IOP.
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Before
The plan is agreed
Deep sclerectomy alone, with a collagen or hyaluronic-acid implant, or converted to trabeculectomy if the anatomy demands. Anti-scarring agents are discussed.
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On the day
Surgery in a dedicated theatre
Usually under local anaesthetic with sedation. A superficial then a deep scleral flap, unroofing of Schlemm’s canal, and creation of a trabeculo-Descemet’s membrane window through which aqueous filters.
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On the day
Home the same day
A shield over the eye, written aftercare, and home within a few hours. Someone drives you back.
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After
Intensive three-month follow-up
Topical steroid and cycloplegic drops, tapered on a schedule. Needling with 5-fluorouracil is offered early if the bleb starts to scar down.
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After
Long-term IOP monitoring
Reviews at three, six and twelve months, then annually. If IOP creeps up, a YAG goniopuncture through the TDM window can restore filtration without a second theatre visit.
Typical end-to-end: workup within 2 weeks, then 12 months of structured follow-up.
When it helps
When deep sclerectomy is the right step.
The situations where a non-penetrating filtration procedure earns its place — plus the red flag that says move quickly.
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Open-angle glaucoma failing drops
Progression on maximal tolerated medical therapy — a signal that a filtration procedure is now the right step.
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Laser therapy no longer holding
When selective laser trabeculoplasty has been tried and IOP is still above the target set for your optic nerve.
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Younger patients and high myopes
Groups in whom classical trabeculectomy carries a higher hypotony risk — a non-penetrating option is often kinder.
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Selected uveitic glaucoma
For carefully chosen inflammatory eyes where a full-thickness bleb would misbehave, deep sclerectomy is sometimes preferred.
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Wish to avoid trabeculectomy risks
Lower rates of shallow anterior chamber, early hypotony and hypotony maculopathy than a classical trabeculectomy.
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Combined with cataract surgery
Where visually significant cataract coexists with uncontrolled glaucoma, phaco-deep-sclerectomy is a single-visit option.
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Bridging to further surgery
A first filtration procedure that keeps trabeculectomy, tube shunt or MIGS revision on the table for later.
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Red flag: rapid field loss
Aggressive visual-field progression despite treatment is not a wait-and-see finding — it is a reason to move quickly.
Options
Deep sclerectomy is not the only option.
What each glaucoma-surgery option on the table actually involves — and where deep sclerectomy sits among them.
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Deep sclerectomy alone
Superficial and deep scleral flaps, Schlemm’s canal unroofed, and a trabeculo-Descemet’s window created. No full-thickness opening.
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With a collagen implant
A small collagen or reticulated hyaluronic-acid implant holds the intrascleral cavity open — supporting long-term filtration.
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Combined phaco-deep-sclerectomy
Cataract removed and deep sclerectomy performed at the same visit for eyes with both problems.
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Converted to trabeculectomy
If the trabeculo-Descemet’s membrane perforates intra-operatively, the surgeon converts to a classical trabeculectomy — planned for, not improvised.
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MIGS alternatives
Minimally invasive glaucoma surgery (iStent, Hydrus, Xen, PreserFlo) can be a lower-risk first step for milder disease.
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Tube-shunt surgery
A Baerveldt or Ahmed drainage device is considered where filtration has already failed or the conjunctiva is too scarred.
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Anti-scarring adjuncts
Intra-operative mitomycin C or postoperative 5-fluorouracil are used selectively to keep the filtration pathway open.
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Postoperative goniopuncture
A quick YAG laser puncture of the TDM window in clinic can rescue an eye whose IOP has drifted upward months later.
Our vetted London network
A small panel of glaucoma surgeons, we picked them.
Consultant ophthalmologists with a glaucoma-fellowship background across central, north, west and south London. Not listed publicly — introductions are made privately, once we understand your case.
Selection criteria
How we choose every glaucoma surgeon in our network.
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Consultant ophthalmologists with a glaucoma fellowship, not generalists
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A meaningful annual caseload of non-penetrating filtration surgery
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Access to intra-operative implants and anti-scarring agents
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Same surgeon available for postoperative needling and YAG goniopuncture
Risks and red flags
What can go wrong — honestly.
Deep sclerectomy has a lower profile of early hypotony than trabeculectomy, but it is still intraocular surgery. These are the complications a good consent conversation covers.
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Intra-operative TDM perforation
The thinnest step of the operation. If the trabeculo-Descemet’s membrane gives way, the surgeon converts to a classical trabeculectomy in the same sitting.
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Delayed hypotony
Less common than after trabeculectomy but still possible — eye pressure that falls too low needs prompt review.
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Hypotony maculopathy
Sustained low pressure can distort the macula and blur central vision. Managed by lifting the pressure back up.
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Sustained shallow anterior chamber
A flat or shallow front chamber in the early days is a reason to be seen the same day, not to wait for the next scheduled visit.
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Scarring and needling failure
The bleb can scar down over weeks to months. Needling with 5-FU is offered early; some eyes still need a second procedure.
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Cataract progression
Any intraocular surgery can accelerate cataract. If it becomes visually significant, cataract surgery is a straightforward next step.
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Choroidal effusion
A collection of fluid behind the retina in the early postoperative period — usually self-limiting but occasionally needs drainage.
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Hyphaema and uveitic flare
A small amount of blood in the front chamber, or a flare of inflammation in a uveitic eye, are recognised early complications.
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Endophthalmitis — rare
Intraocular infection is uncommon but sight-threatening. Sudden pain, redness or vision loss after surgery is an emergency, day or night.
Reading your operation note
Your operation note in four parts. Read the last one first.
Whether the surgery ran as a pure deep sclerectomy, went in with an implant, or converted to trabeculectomy, the note the surgeon sends you keeps to the same shape.
A quiet reminder
Surgical language is precise and can read coldly — we translate it for you.
If you would like us to talk you through the note before your review, just ask.
- 01 Header
Diagnosis and target IOP
The type of glaucoma, the eye operated on, and the target intra-ocular pressure the surgeon was aiming for.
- 02 Technique
Flaps, implant and anti-scarring
Whether an implant was placed, whether mitomycin C was used, and whether the case was converted to trabeculectomy at any point.
- 03 Findings
TDM window and Schlemm’s canal
Notes on how the trabeculo-Descemet’s membrane behaved, how well aqueous percolated through it, and any incidental findings.
- 04 Impression
Drop schedule, review dates, goniopuncture plan
Read this first: the steroid and cycloplegic taper, when to be seen, and whether a YAG goniopuncture is planned if IOP drifts up.
Frequently asked
Everything we get asked about deep sclerectomy.
Quick answers on how it differs from trabeculectomy, what happens if the membrane perforates, and whether you will still need drops.
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What is deep sclerectomy, and how does it differ from trabeculectomy?
Deep sclerectomy is a non-penetrating filtration operation for open-angle glaucoma. Unlike trabeculectomy, it does not create a full-thickness hole into the eye — the trabeculo-Descemet’s membrane is left intact so aqueous filters through it. That preserved membrane is what gives deep sclerectomy its lower rate of early hypotony and shallow anterior chamber.
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Who is a good candidate for deep sclerectomy?
Adults with open-angle glaucoma whose intra-ocular pressure is no longer controlled on maximal tolerated drops or after laser therapy. It is often preferred in younger patients, high myopes and selected uveitic eyes, where a classical trabeculectomy would carry a higher risk of hypotony.
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What happens if the membrane perforates during surgery?
The surgeon converts to a classical trabeculectomy in the same sitting. This is a planned-for possibility, not a failure — the visual outcome is typically similar, but the postoperative regimen becomes that of a trabeculectomy.
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What is a goniopuncture, and will I need one?
If pressure drifts up months after surgery, a YAG laser goniopuncture through the trabeculo-Descemet’s window can restore filtration in clinic, without returning to theatre. Around a third of eyes benefit from it at some point.
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How does recovery compare with trabeculectomy?
Recovery is usually quicker and calmer. Fewer eyes develop very low pressures or a shallow front chamber, and the visual dip in the first weeks tends to be less pronounced. The intensive follow-up schedule — drops, reviews, occasional needling — is still similar.
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Will I still need glaucoma drops afterwards?
Many patients reduce their drop burden significantly, and some come off drops entirely, but that is not guaranteed. The aim of surgery is a safer, lower pressure — reducing drops is a welcome bonus rather than the primary goal.
Sources
Where this guide comes from.
- European Glaucoma Society. Terminology and guidelines for glaucoma.
- The Royal College of Ophthalmologists. Glaucoma surgical guidance.
- American Academy of Ophthalmology. Deep sclerectomy — clinical resource.
- World Glaucoma Association. Consensus on angle surgery and non-penetrating filtration.
Last reviewed 2026-07-30. Next review 2027-07-30. This guide is educational and does not replace advice from the ophthalmologist looking after your eyes.
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