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PubMed This is a summary of 18 peer-reviewed journal articles Updated
Ophthalmology

Surgical Treatment: MIGS, Trabeculectomy & Tubes

At a Glance

Surgery for open-angle glaucoma lowers eye pressure to protect remaining vision when drops or laser are not enough; it cannot restore lost sight. MIGS has faster recovery and modest pressure lowering, while trabeculectomy and tube shunts require more aftercare and can lower pressure further.

Surgery is often considered for open-angle glaucoma (OAG) when eye drops and laser treatments (SLT) are no longer enough to reach your target IOP, or when your disease continues to progress despite these treatments [1][2]. However, surgery is not always a last resort; if you have advanced damage, very high pressure, rapid progression, severe medication intolerance, or major barriers to using daily drops, your doctor may recommend surgery earlier in your treatment plan.

It is vital to understand that glaucoma surgery is a “protective” measure. Its goal is to preserve the vision you have left by lowering eye pressure; it cannot restore vision that has already been lost to nerve damage [3][4].

Minimally Invasive Glaucoma Surgery (MIGS)

MIGS refers to a broad group of newer procedures designed to lower eye pressure with less tissue disruption and a faster recovery than traditional surgery [5]. These are most often performed at the same time as cataract surgery for patients with mild-to-moderate glaucoma [6].

  • How they work: Devices like the iStent or Hydrus are tiny stents placed into the eye’s natural drainage canal to help fluid bypass the resistant meshwork [7][8]. Other techniques involve removing a small strip of the drainage tissue itself [9].
  • The Benefits: MIGS generally has a favorable safety profile compared to traditional surgery. The primary goal is often to reduce the number of daily eye drops a patient needs while providing a modest reduction in pressure [5][6].
  • The Risks: While generally safer, MIGS is not risk-free. Depending on the exact procedure, risks can include bleeding inside the eye (hyphema), post-operative pressure spikes, inflammation, device malposition, or a failure to reach the target pressure (requiring you to stay on drops or undergo further surgery) [10].

Traditional Filtering Surgery: Trabeculectomy & Tube Shunts

For patients who need a significant, powerful drop in eye pressure—especially in advanced or rapidly progressing disease—traditional surgeries remain powerful, established options [2].

  • Trabeculectomy: Your surgeon creates a tiny new “trapdoor” in the white of the eye (sclera). This allows fluid to bypass the natural drain and flow into a newly created reservoir called a filtering bleb [11]. The fluid in this clear “blister,” which is usually hidden under the upper eyelid, is naturally absorbed back into the body’s circulation [12].
  • Glaucoma Drainage Devices (Tube Shunts): If a trabeculectomy is not suitable or has failed previously, surgeons may implant a tiny silicone tube that shunts fluid to a small plate placed further back on the eye.
  • Success Rates: These procedures are highly effective at reaching lower target pressures, which is often necessary to stop progression in advanced cases [5][13].

Risks and Post-Operative Care

While powerful, traditional surgery requires a much longer and more “hands-on” recovery period than MIGS [14].

The Importance of the Bleb

A successful trabeculectomy depends entirely on how the bleb heals. To prevent the body from scarring the new drain closed, surgeons use anti-scarring medications like Mitomycin-C during the procedure [3]. Your doctor will monitor you closely, sometimes weekly in the first month, to ensure the bleb is forming correctly [12][15].

Potential Complications

  • Hypotony: If the eye pressure drops too low, the eye can become “soft,” leading to blurry vision or swelling in the back of the eye (hypotony maculopathy) [16][3].
  • Bleb Leaks and Infection: If the bleb develops a tiny leak, bacteria can enter the eye. This can lead to a serious infection called blebitis or endophthalmitis. Crucially, bleb leaks and infections can occur months or even years after the original surgery. You must inform any future eye-care clinicians that you have a filtering bleb [3][17].
  • Cataract Progression: Traditional glaucoma surgery can sometimes cause a pre-existing cataract to worsen more quickly [18].

Surgeon-Specific Aftercare

Your recovery timeline will be tailored to you. Expect to use frequent anti-inflammatory drops and follow strict rules regarding eye protection, physical exertion, and keeping water out of your eye. Always follow your surgeon’s specific individualized plan rather than general advice.

While the recovery can be demanding, successful surgery is one of the best tools available to protect your sight for the long term.

Common questions in this guide

When is surgery recommended for open-angle glaucoma?
Surgery may be recommended when eye drops and selective laser trabeculoplasty (SLT) do not lower eye pressure to the target level or glaucoma continues to worsen. It may be considered earlier when damage is advanced, pressure is very high, disease is progressing quickly, medicines are not tolerated, or daily drops are difficult to use.
What is the difference between MIGS, trabeculectomy, and tube shunt surgery?
MIGS uses small devices or limited tissue removal to improve fluid drainage, usually with cataract surgery, and generally offers faster recovery and a modest pressure reduction. Trabeculectomy creates a new drainage route, while a tube shunt directs fluid to a plate; these traditional procedures can lower pressure more but require longer, closer aftercare.
Can glaucoma surgery restore vision that I have already lost?
No. Glaucoma surgery lowers eye pressure to protect remaining vision, but it cannot reverse optic-nerve damage or restore vision already lost from glaucoma.
Will MIGS allow me to stop using glaucoma eye drops?
MIGS may reduce the number of daily drops, but stopping all medication is not guaranteed. If eye pressure remains above target, you may still need drops or additional treatment, including another surgery.
What complications can happen after glaucoma surgery?
Risks vary by procedure. MIGS can cause bleeding, inflammation, pressure spikes, device problems, or pressure that remains too high; traditional surgery can cause pressure that is too low, a leaking or infected filtering bleb, or faster cataract progression.
What is recovery like after a trabeculectomy or tube shunt?
Recovery usually involves frequent anti-inflammatory drops, eye protection, limits on physical activity and water exposure, and close visits that may be weekly during the first month. A filtering-bleb leak or infection can occur months or years later, so contact your eye-care team promptly if you are concerned and tell future eye-care clinicians that you have a bleb.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on my current stage of glaucoma, why is surgery being recommended over continuing with medications or laser?
  2. 2.If we choose a MIGS procedure, what is the realistic chance I will be able to stop all my glaucoma eye drops?
  3. 3.What is your specific plan for monitoring me after a trabeculectomy or tube shunt, and how often will I need to be seen in the first month?
  4. 4.What signs of infection or 'bleb leakage' should I watch for, and how quickly would I need to reach you if they occur?
  5. 5.If the surgery fails to reach my target pressure, what are the next steps?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (18)
  1. 1

    The PreserFlo MicroShunt in the Context of Minimally Invasive Glaucoma Surgery: A Narrative Review.

    Saeed E, Gołaszewska K, Dmuchowska DA, et al.

    International journal of environmental research and public health 2023; (20(4)) doi:10.3390/ijerph20042904.

    PMID: 36833599
  2. 2

    Ab-Externo MicroShunt versus Trabeculectomy in Primary Open-Angle Glaucoma: Two-Year Results from a Randomized, Multicenter Study.

    Panarelli JF, Moster MR, Garcia-Feijoo J, et al.

    Ophthalmology 2024; (131(3)):266-276 doi:10.1016/j.ophtha.2023.09.023.

    PMID: 37769852
  3. 3

    Wound Healing and Glaucoma Surgery: Modulating the Scarring Process with Conventional Antimetabolites and New Molecules.

    Holló G

    Developments in ophthalmology 2017; (59()):80-89 doi:10.1159/000458488.

    PMID: 28442689
  4. 4

    Early postoperative visual acuity changes after trabeculectomy and factors affecting visual acuity.

    Sato N, Kasahara M, Kono Y, et al.

    Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie 2023; (261(9)):2611-2623 doi:10.1007/s00417-023-06076-3.

    PMID: 37103621
  5. 5

    Glaucoma Surgery: From the Tried and True to the Novel and New.

    Gedde SJ, Herndon LW

    Ophthalmology. Glaucoma 2025; (8(5S)):S49-S57 doi:10.1016/j.ogla.2025.06.009.

    PMID: 40742348
  6. 6

    Should Schlemm Canal-Based MIGS Be Combined with Cataract Surgery in Patients Receiving Topical Glaucoma Therapy? A Cataract Surgeon-Oriented Review.

    Nakagawa S, Kaburaki T, Ishii K

    Journal of clinical medicine 2026; (15(14)) doi:10.3390/jcm15145503.

    PMID: 42513417
  7. 7

    A Prospective Randomized Trial Comparing Hydrus and iStent Microinvasive Glaucoma Surgery Implants for Standalone Treatment of Open-Angle Glaucoma: The COMPARE Study.

    Ahmed IIK, Fea A, Au L, et al.

    Ophthalmology 2020; (127(1)):52-61 doi:10.1016/j.ophtha.2019.04.034.

    PMID: 31034856
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    Minimally Invasive Glaucoma Surgical Techniques for Open-Angle Glaucoma: An Overview of Cochrane Systematic Reviews and Network Meta-analysis.

    Bicket AK, Le JT, Azuara-Blanco A, et al.

    JAMA ophthalmology 2021; (139(9)):983-989 doi:10.1001/jamaophthalmol.2021.2351.

    PMID: 34264292
  9. 9

    Excisional goniotomy vs trabecular microbypass stent implantation: a prospective randomized clinical trial in eyes with mild to moderate open-angle glaucoma.

    Falkenberry S, Singh IP, Crane CJ, et al.

    Journal of cataract and refractive surgery 2020; (46(8)):1165-1171 doi:10.1097/j.jcrs.0000000000000229.

    PMID: 32358417
  10. 10

    Systematic Literature Review of Clinical and Economic Outcomes of Micro-Invasive Glaucoma Surgery (MIGS) in Primary Open-Angle Glaucoma.

    Agrawal P, Bradshaw SE

    Ophthalmology and therapy 2018; (7(1)):49-73 doi:10.1007/s40123-018-0131-0.

    PMID: 29725860
  11. 11

    Functional, structural, and molecular identification of lymphatic outflow from subconjunctival blebs.

    Akiyama G, Saraswathy S, Bogarin T, et al.

    Experimental eye research 2020; (196()):108049 doi:10.1016/j.exer.2020.108049.

    PMID: 32387381
  12. 12

    Bleb Morphology After Mitomycin-C Augmented Trabeculectomy: Comparison Between Clinical Evaluation and Anterior Segment Optical Coherence Tomography.

    Waibel S, Spoerl E, Furashova O, et al.

    Journal of glaucoma 2019; (28(5)):447-451 doi:10.1097/IJG.0000000000001206.

    PMID: 30720575
  13. 13

    Efficacy and Safety Outcomes of XEN Implantation and Gonioscopy-assisted Transluminal Trabeculotomy for the Management of Advanced Open-angle Glaucoma.

    Ruparelia S, Sharif M, Shoham-Hazon N

    Journal of current glaucoma practice 2023; (17(2)):63-67 doi:10.5005/jp-journals-10078-1394.

    PMID: 37485457
  14. 14

    Clinical practice preferences for glaucoma surgery in Japan: a survey of Japan Glaucoma Society specialists.

    Iwasaki K, Arimura S, Takamura Y, Inatani M

    Japanese journal of ophthalmology 2020; (64(4)):385-391 doi:10.1007/s10384-020-00749-w.

    PMID: 32474840
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    Anterior-Segment Optical Coherence Tomography for Predicting Postoperative Outcomes After Trabeculectomy.

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    Current eye research 2018; (43(6)):762-770 doi:10.1080/02713683.2018.1446535.

    PMID: 29513109
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    Incidence of short-term complications and associated factors after primary trabeculectomy in Chiang Mai University Hospital.

    Leeungurasatien T, Khunsongkiet P, Pathanapitoon K, Wiwatwongwana D

    Indian journal of ophthalmology 2016; (64(10)):737-742 doi:10.4103/0301-4738.195011.

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    ENDOPHTHALMITIS CAUSED BY PSEUDOMONAS AERUGINOSA: Clinical Features, Antibiotic Susceptibilities, and Treatment Outcomes.

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    Postoperative Complications in the Primary Tube Versus Trabeculectomy Study During 5 Years of Follow-up.

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    PMID: 35835336

This page is for informational purposes only and does not constitute medical advice. Your ophthalmologist should help you choose a procedure and provide individualized instructions for recovery and follow-up.

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