[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Ophthalmology](https://durgical.com/en/ophthalmology/) › [Eye surgery and procedures](https://durgical.com/en/ophthalmology/areas/surgery/) › Glaucoma lasers and surgery: from iridotomy to tube shunts # Glaucoma lasers and surgery: from iridotomy to tube shunts - Topic When drops are not enough, laser or surgery lowers eye pressure. After glaucoma surgery, a red, sticky eye can mean bleb infection: refer the same day. Updated Nov 13, 2026 **See it in 3D:** [Drainage angle](https://durgical.com/en/anatomy/iridocorneal-angle/) · [Iris](https://durgical.com/en/anatomy/iris/) · [Ciliary body](https://durgical.com/en/anatomy/ciliary-body/) ## Key points - Iridotomy = angle closure, both eyes. - Laser trabeculoplasty = open angle, can be first-line. - Trabeculectomy = bleb + mitomycin C. - Red sticky eye with a bleb = infection until proven otherwise. - Cyclodestruction for refractory or blind painful eyes. ## What it is Every glaucoma treatment lowers intraocular pressure. Laser peripheral iridotomy opens a small hole in the peripheral iris so aqueous bypasses the pupil, treating and preventing angle closure. Selective laser trabeculoplasty improves outflow through the trabecular meshwork in open-angle glaucoma. Trabeculectomy creates a guarded channel that drains aqueous under the conjunctiva into a bleb; tube shunts carry aqueous to a plate behind the eye; minimally invasive glaucoma surgery (MIGS) uses tiny devices or incisions; cyclodestruction reduces aqueous production. ## Key facts - Iridotomy: after an acute angle-closure attack (once the pressure is lowered), in the fellow eye, and in narrow angles at risk of closing. - Selective laser trabeculoplasty: open-angle glaucoma and ocular hypertension; a valid first-line alternative to drops; the effect fades over years and it can be repeated. - Trabeculectomy: antifibrotic agents (mitomycin C or fluorouracil) are applied to stop scarring; the bleb sits under the upper lid. - Tube shunts: after failed trabeculectomy, and in neovascular, uveitic or complex glaucoma; risks include tube exposure and loss of corneal endothelium. - MIGS: often combined with cataract surgery in mild to moderate glaucoma; safer but with a smaller pressure drop. - Cyclodestruction (diode laser to the ciliary body): refractory glaucoma or blind, painful eyes; risks are inflammation and very low pressure (hypotony). ## In clinical practice - A bleb can become infected months or years after surgery: red eye, discharge, a milky white bleb, pain and blurred vision; it can progress to endophthalmitis within hours. - Pressure that is too low after surgery (hypotony) blurs vision through choroidal folds, effusions or macular folds. - Rubbing the eye and wearing contact lenses over a bleb raise the risk of infection and leakage. - A 'conjunctivitis' in an eye with a bleb or tube is never treated as routine pink eye. ## Next step / Initial management - Red eye, discharge or pain in an eye with a trabeculectomy bleb or a tube: same-day ophthalmology (bleb infection or endophthalmitis). - Acute angle closure: lower the pressure first, then ophthalmology performs iridotomy in both eyes. - Glaucoma that progresses on drops, or a patient who cannot use or tolerate drops: refer to discuss laser or surgery. - After surgery, follow the drop plan given by ophthalmology; glaucoma drops in the operated eye are often stopped, those in the other eye are not. - Sudden loss of vision or severe pain after glaucoma surgery: same-day review. ## Test yourself Think of the answer, then tap the question to see it. ## What does laser peripheral iridotomy do, and when is it used? It opens a hole in the peripheral iris so aqueous bypasses pupillary block; it is used in angle closure, in the fellow eye and in narrow angles at risk. ## Which drug is applied during trabeculectomy to reduce scarring of the bleb? Mitomycin C (or fluorouracil). ## Years after a trabeculectomy, a patient has a red, discharging eye with a milky bleb. What is it and what is the next step? A bleb-related infection that can progress to endophthalmitis; same-day ophthalmology. ## Which glaucoma procedure lowers pressure by reducing aqueous production rather than improving outflow? Cyclodestruction of the ciliary body, usually with a diode laser. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/ophthalmology/glaucoma-lasers-and-surgery-from-iridotomy-to-tube-shunts/) ## Connections ## See it in 3D 3 The structures of Durgical's 3D anatomy where it is found. - [Drainage angle](https://durgical.com/en/anatomy/iridocorneal-angle/) - [Iris](https://durgical.com/en/anatomy/iris/) - [Ciliary body](https://durgical.com/en/anatomy/ciliary-body/) ## Related 5 - [Tonometry: measuring intraocular pressure](https://durgical.com/en/ophthalmology/tonometry-measuring-intraocular-pressure/) - [The anterior chamber and the drainage angle](https://durgical.com/en/ophthalmology/the-anterior-chamber-and-the-drainage-angle/) - [Gonioscopy: looking into the drainage angle](https://durgical.com/en/ophthalmology/gonioscopy-looking-into-the-drainage-angle/) - [Acute angle closure: what to do before the ophthalmologist](https://durgical.com/en/ophthalmology/acute-angle-closure-what-to-do-before-the-ophthalmologist/) - [Eye drops and ointments: how they are given and absorbed](https://durgical.com/en/ophthalmology/eye-drops-and-ointments-how-they-are-given-and-absorbed/) ## Related conditions 4 - [Open-angle glaucoma](https://durgical.com/en/conditions/open-angle-glaucoma/) - [Acute angle-closure glaucoma](https://durgical.com/en/conditions/acute-angle-closure-glaucoma/) - [Neovascular glaucoma](https://durgical.com/en/conditions/neovascular-glaucoma/) - [Endophthalmitis](https://durgical.com/en/conditions/endophthalmitis/) ## In Pharmacology 3 - [Mitomycin](https://durgical.com/en/pharmacology/mitomycin/) - [Fluorouracil](https://durgical.com/en/pharmacology/fluorouracil/) - [Antiglaucoma agents](https://durgical.com/en/pharmacology/classes/antiglaucoma-agents/) [← All of ophthalmology](https://durgical.com/en/ophthalmology/) Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once. Sources: [Laser Trabeculoplasty](https://www.ncbi.nlm.nih.gov/books/NBK578175/) (StatPearls Publishing (NCBI Bookshelf), 2023); [Minimally Invasive Glaucoma Surgery](https://www.ncbi.nlm.nih.gov/books/NBK582156/) (StatPearls Publishing (NCBI Bookshelf), 2023); [Cyclodiode Laser Glaucoma Therapy](https://www.ncbi.nlm.nih.gov/books/NBK574570/) (StatPearls Publishing (NCBI Bookshelf), 2022); [Trabeculectomy](https://eyewiki.org/Trabeculectomy) (EyeWiki (American Academy of Ophthalmology), 2025); [Laser Peripheral Iridotomy](https://eyewiki.org/Laser_Peripheral_Iridotomy) (EyeWiki (American Academy of Ophthalmology), 2025); [Glaucoma Drainage Devices](https://eyewiki.org/Glaucoma_Drainage_Devices) (EyeWiki (American Academy of Ophthalmology), 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/ophthalmology/glaucoma-lasers-and-surgery-from-iridotomy-to-tube-shunts/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/ophthalmology/glaucoma-lasers-and-surgery-from-iridotomy-to-tube-shunts/