Glaucoma Surgery and Lasers in Toulon: SLT, Iridotomy, Trabeculectomy and MIGS

Glaucoma surgery and lasers have a single goal: to lower intraocular pressure in order to preserve the optic nerve and vision. Glaucoma is a progressive, irreversible degeneration of the optic nerve, most often caused by excessive eye pressure. The second leading cause of blindness worldwide, it causes loss of the visual field and then of vision. No treatment cures glaucoma, but a complete therapeutic arsenal — eye drops, lasers (SLT, YAG iridotomy, diode laser) and surgery (trabeculectomy, sclerectomy, MIGS, drainage valves) — can stabilise or slow its progression. The strategy follows a stepwise escalation: eye drops first, then in-office laser if insufficient, and finally surgery in the operating room for the most severe cases.

Expert insight

“Glaucoma lasers and surgery are really treatments for eye pressure. They are not there to improve vision, but to prevent its loss! The earlier glaucoma is managed, the better the prognosis. Because the optic nerve cannot regenerate, whatever is lost stays lost: it is therefore crucial to act before the damage becomes too great.”

Dr Hugo Bourdon

Why operate on glaucoma? Goal and principle

Glaucoma progressively destroys the fibres of the optic nerve under the effect of an intraocular pressure that is too high. This destruction is irreversible: lost fibres do not regenerate and lost visual field is not recovered. The goal of all treatments — eye drops, lasers or surgery — is therefore the same: to lower the intraocular pressure to slow or stop the progression of the disease.

To achieve this, two mechanisms are possible:

• Increase the drainage of aqueous humour — the principle of most treatments: SLT trabeculoplasty, iridotomy, trabeculectomy, sclerectomy, MIGS and valves.
• Reduce the secretion of aqueous humour — the principle of the diode laser (cyclophotocoagulation) and of some eye drops (beta-blockers, carbonic anhydrase inhibitors).

How does the treatment escalation work?

Glaucoma treatment follows a logic of gradual escalation, adapted to the severity of the disease and the patient’s response. At each step the goal stays the same: to reach a “target” eye pressure low enough to stabilise the disease.

Step 1: hypotensive eye drops (medical treatment)

Eye drops are the first-line treatment for glaucoma. Several classes can be used alone or in combination:

• Prostaglandin analogues (latanoprost, bimatoprost, travoprost) — increase the drainage of aqueous humour. The most prescribed, as they work with a single daily drop.
• Beta-blockers (timolol, betaxolol) — reduce the production of aqueous humour. Contraindicated in asthma or heart conditions.
• Carbonic anhydrase inhibitors (dorzolamide, brinzolamide) — also reduce production.
• Alpha-agonists (brimonidine) — dual action: reduce production and increase drainage.
• Fixed combinations — combine two active ingredients in one bottle to simplify treatment and improve adherence.

Eye drops are effective in most patients but require a daily drop for life. Their main drawback is the risk of poor adherence, dry eye and long-term skin allergies. This is why laser may be offered as a complement, or even as first-line treatment.

Step 2: in-office laser treatments

Glaucoma lasers are performed in the office in a few minutes, under local drop anaesthesia. They may be offered first-line (to avoid drops) or as a complement to drops (to reinforce their effect and avoid surgery).

Step 3: surgery in the operating room

When drops and laser are not enough to control eye pressure, or the glaucoma keeps progressing despite treatment, surgery in the operating room is needed. These procedures are more effective but carry more risk and require close follow-up.

Selective laser trabeculoplasty (SLT) — open-angle glaucoma

Selective laser trabeculoplasty (SLT) is the reference laser for open-angle glaucoma, the most common form of the disease.

• Principle — the laser selectively stimulates the pigmented cells of the trabecular meshwork (the eye’s drainage filter) without destroying them, improving the drainage of aqueous humour.
• Indications — primary open-angle glaucoma, pigmentary glaucoma, pseudoexfoliative glaucoma. Can be offered first-line (before drops) or as a complement.
• Procedure — in the office, seated at a slit lamp. A lens is placed on the eye, then about 50 painless laser spots are applied to the trabecular meshwork. Duration: 5 to 10 minutes.
• Effectiveness — lowers eye pressure by about 20%, comparable to a drop. The effect can last 2 to 5 years.
• Advantages — painless, non-destructive, repeatable if needed. Sometimes lets you reduce or stop drops.
• Aftercare — anti-inflammatory drops for 1 week. Immediate return to activities.
• Dr Bourdon’s fee — €125 (Social Security) + €40 fee supplement (insurance).

Peripheral YAG laser iridotomy — closed-angle glaucoma

Peripheral iridotomy is the reference laser treatment for closed-angle glaucoma (acute or chronic) and its prevention.

• Principle — the laser creates a tiny opening (almost invisible to the naked eye) in the periphery of the iris, restoring the flow of aqueous humour between the posterior and anterior chambers. The drainage angle reopens and the pressure falls.
• Indications — acute closed-angle glaucoma (emergency), chronic angle-closure glaucoma, prevention in patients with a narrow angle. Also offered in pigmentary glaucoma.
• Procedure — in the office, seated. A few laser spots are applied to the periphery of the iris after a drop of pilocarpine (which constricts the pupil). Duration: a few minutes.
• Effectiveness — very effective at preventing and treating angle closure. May not be enough alone: cataract surgery or trabeculectomy is sometimes needed to stabilise the pressure for good.
• Aftercare — dim vision for 24h (pilocarpine effect). Anti-inflammatory drops for 1 week.
• Dr Bourdon’s fee — €83 (Social Security) + €40 fee supplement (insurance).

Trabeculectomy — the reference filtering surgery

Trabeculectomy is the most commonly performed glaucoma operation in the world when drops and laser are no longer enough.

• Principle — the surgeon creates a new drainage route for the aqueous humour by making an opening through the trabecular meshwork, covered by a scleral flap. The fluid drains under the conjunctiva where it forms a “filtering bleb”, creating a permanent shunt that lowers the eye pressure.
• Indications — open- or closed-angle glaucoma not controlled by drops and laser. Severe or rapidly progressing glaucoma requiring a large pressure reduction.
• Stay — day case, in the operating room. Local anaesthesia with sedation, or general.
• Effectiveness — the most powerful surgery: pressure reduction of 30 to 40%. It often lets you reduce or stop drops.
• Follow-up — very close in the first weeks. Healing of the filtering bleb must be watched carefully. Adjustments are sometimes needed: laser removal of adjustable sutures, or needling if the bleb heals too much.
• Risks — ocular hypotony (pressure too low), inflammation, bleb infection (blebitis), excessive scarring requiring re-operation, transient drop in vision.

Non-penetrating deep sclerectomy (NPDS)

Non-penetrating deep sclerectomy is an alternative to trabeculectomy, developed to offer filtering surgery with less risk of post-operative hypotony.

• Principle — the surgeon thins the trabecular meshwork without perforating it (hence “non-penetrating”), letting the aqueous humour seep through this thin residual membrane. A collagen implant can be placed to keep the filtration space open.
• Indications — open-angle glaucoma. Chosen especially when the risk of hypotony is high or a gentler surgery is wanted.
• Advantages — less risk of hypotony and of immediate post-operative complications than trabeculectomy.
• Limits — slightly less effective than trabeculectomy. Sometimes needs a laser “goniopuncture” afterwards to perforate the thin remaining membrane and increase filtration.

MIGS — minimally invasive glaucoma surgery

MIGS (Micro-Invasive Glaucoma Surgery) is a set of innovative, minimally invasive surgical techniques developed to offer an alternative to classic filtering surgery.

• Principle — depending on the device, MIGS ease the drainage of aqueous humour through Schlemm’s canal (trabecular stents such as the iStent), through the subconjunctival space (XEN Gel Stent, PreserFlo), or via the suprachoroidal route.
• Indications — mild to moderate glaucoma. Often performed together with cataract surgery for a double benefit in a single procedure.
• Advantages — less invasive than trabeculectomy, faster recovery, less demanding follow-up.
• Limits — pressure reduction generally lower than trabeculectomy. Long-term data are still limited for some devices, several of which have been withdrawn from the market after a few years. Caution remains warranted.

Drainage valves (Ahmed, Baerveldt implants)

Drainage valves are implantable devices of last resort, reserved for complex or refractory glaucoma.

• Principle — a thin tube is inserted into the anterior chamber of the eye and connected to a plate placed under the conjunctiva, behind. The aqueous humour drains through the tube to the plate, creating permanent drainage.
• Indications — refractory glaucoma after failed filtering surgery, neovascular glaucoma, post-traumatic glaucoma, uveitic glaucoma.
• Models — the Ahmed valve (with a regulating mechanism) and the Baerveldt implant (no valve) are the two most used.
• Risks — hypotony, conjunctival erosion, tube obstruction, corneal contact.

Diode laser — cyclophotocoagulation for refractory glaucoma

The diode laser treats refractory glaucoma, that is glaucoma not controlled despite classic medical, laser and surgical treatments.

• Principle — unlike the other techniques that increase drainage, the diode laser works by reducing the production of aqueous humour. It partly “cauterises” the ciliary bodies (the structures that secrete aqueous humour) through the sclera.
• Two techniques — the thermal (continuous) mode is the most powerful but can cause more complications. The micropulse (fractionated) mode is gentler, less painful, and carries less risk of hypotony.
• Indications — refractory glaucoma, neovascular glaucoma, post-traumatic glaucoma, or a frail patient who cannot undergo filtering surgery.
• Risks — ocular hypotony, inflammation, post-operative pain (thermal mode), need for re-treatment.

Comparison of glaucoma surgery and lasers

Cataract surgery and glaucoma: a double benefit

In patients with both glaucoma and a cataract, cataract surgery can bring a double benefit: improved vision by replacing the clouded lens, and lower eye pressure by opening the iridocorneal angle. This is especially true in closed-angle glaucoma, where the bulky lens contributes to angle closure. An additional pressure-lowering step can also be performed at the end of the operation: placing a drain (iStent-type MIGS), treating both conditions in a single operation.

Which treatment for which type of glaucoma?

In summary

Glaucoma is a chronic disease that needs lifelong follow-up. While no treatment cures it, today’s therapeutic arsenal — eye drops, lasers and surgery — preserves vision effectively in the vast majority of cases, provided care is early and follow-up is regular with a specialist ophthalmologist. The choice of treatment depends on the type of glaucoma, its severity, and the individual response. Do not hesitate to come in for an assessment of your situation and to define the most suitable strategy.

Frequently asked questions about glaucoma surgery

Sources and references

• NHS — Glaucoma treatment
• EyeWiki — Selective Laser Trabeculoplasty
• EyeWiki — Trabeculectomy
• American Academy of Ophthalmology — Glaucoma Treatment
• QualiDoc — Glaucoma treatments

Article written and reviewed by Dr Hugo Bourdon, ophthalmic surgeon at the Clinique Saint-Michel ELSAN and the Centre Iris – Institut Toulonnais d’Ophtalmologie (281 rue Jean Jaurès, Toulon). Last updated: 16 April 2026.