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Dr Chelvin Sng's guide to after-glaucoma surgery (2024)

Undergoing glaucoma surgery in Singapore can be a daunting process, but thanks to new advances in ophthalmology medicine and technology, it isn’t as intimidating anymore – including the recovery process.

Can you lead a normal life after glaucoma surgery? Will surgery improve your vision? Will your eye pressure go back up?

For this article, I will talk about the three most commonly performed types of glaucoma surgeries - trabeculectomy, tube implant surgery, and minimally invasive glaucoma surgery (MIGS).

How is glaucoma surgery done in Singapore?

If glaucoma laser treatment and medications haven’t lowered your eye pressure sufficiently, or if you’re experiencing side effects from the medications, your doctor may recommend surgery instead1.

There are a few types of glaucoma surgeries that can lower the pressure in your eyes, including:

Type of surgeryHow it worksWhat does it treats
TrabeculectomyThe surgeon creates a tiny opening in the top part of your eye, under your eyelid. The opening enables fluid in your eye to drain away, reducing the eye pressure.Open angle glaucoma Angle closure glaucoma
Tube implant surgeryThe surgeon implants a tube into your eye. The tube helps to drain excess fluid from your eye. There are a few types of tube implants. I am part of a team which helped to develop the Paul Glaucoma Implant (PGI), a novel tube implant. Study results suggest that the PGI is associated with a lower rate of complications compared with previous tube implants, with higher efficacy compared with some of the previous tube implants.Open angle glaucoma Angle closure glaucoma Congenital glaucoma Secondary glaucoma, including uveitic glaucoma, traumatic glaucoma and neovascular glaucoma
Minimally invasive glaucoma surgery (MIGS)Microscopic implants are inserted into the eye with small incisions. The safety profile of MIGS is higher compared with conventional glaucoma surgery, and it effectively lowers the eye pressure in appropriately selected glaucoma patients.Mild to moderate glaucoma

It is important to note that there is no cure for glaucoma – even with surgery. The damage inflicted on the eye nerve by glaucoma is irreversible. Glaucoma surgery aims to lower eye pressure and prevent further vision loss2.

Do and don’ts after glaucoma surgery in Singapore

Type of surgeryPost-operation protocolSide effects and period
Trabeculectomy1. Wear an eye shield when sleeping for up to 3-4 weeks after surgery.
2. Do not rub or press on your eye after surgery, to avoid infection or injury to the eye.
3. Use antibiotic and steroid eye drops as prescribed by your doctor after the surgery. Antibiotic eyedrops are generally required for about a month. Steroid eyedrops are to be instilled 6-8 times a day initially, and the frequency will be gradually reduced. Steroid eyedrops may be required for several months after surgery.
4. Do not bend over and avoid strenuous activities such as weightlifting until your doctor says that it is safe to do so.
5. Do not use eye make-up for at least 3 weeks after surgery.
6. Avoid contact lens wear until your doctor says that it is safe to do so.
7. Do not swim for at least a month. Swimming can cause serious infections after surgery. Some patients who have undergone trabeculectomy would need to avoid swimming permanently,
Discomfort and blurry vision may last for up to a few weeks after the surgery.  Some patients experience permanent eye discomfort or dryness after trabeculectomy, and they may also have a life-long risk of sight-threatening eye infection.
Tube implant surgerySame as Trabeculectomy, except it is unlikely that patients with tube implants would need to avoid swimming permanentlyDiscomfort and blurry vision may last for up to a few weeks after the surgery.  Permanent eye discomfort or dryness after tube implant surgery is unlikely. Patients with tube implants also usually do not have a life-long risk of sight-threatening infection.
 MIGSSame as trabeculectomy, except a shorter duration of steroid eyedrops is required (often just 1-2 months). It is also unlikely that patients who have undergone MIGS would need to avoid swimming permanently.Compared to trabeculectomy and tube implant surgery, MIGS is a lot less invasive, hence recovery is a lot faster, often with good vision within a week.   Permanent eye discomfort or dryness after MIGS is unlikely. Patients with MIGS also usually do not have a life-long risk of sight-threatening infection.  

Can I lead a normal life after glaucoma surgery in Singapore?

Ultimately, the aim of glaucoma surgery is to preserve your vision by lowering your eye pressure.  MIGS patients often experience a fast recovery and most patients can return to normal activities soon after surgery. Patients with tube implants also often resume their normal activities 1-2 months after surgery, and usually do not need to make long-term changes to their lifestyle.

Unfortunately, many trabeculectomy patients are unable to swim for life, as they have a life-long risk of sight-threatening infection. With that said, recovery and quality of life after surgery vary amongst patients depending on how you respond to the surgery.

It is important to note that surgery is unable to reverse your vision loss from glaucoma – regardless of the type of surgery.

Surgery aims to prevent further vision loss and further damage to the eye nerve. This allows you to continue to be independent in your daily activities. Depending on the severity of your glaucoma, you may still require glaucoma medications after surgery. However, glaucoma surgery also often reduces the number of glaucoma medications required, hence improving your quality of life by reducing the side effects from these medications3.

To achieve the best outcomes after glaucoma surgery, I emphasize the importance of using the post-operative eyedrops as prescribed, and the need for regular review after surgery so that your doctor can monitor the eye pressure and alter the medications accordingly.

Eye check, glaucoma, glaucoma surgery,  Minimally Invasive Glaucoma Surgery

What are the risks of glaucoma surgery?

As with all surgeries, glaucoma surgery are associated with some risks. To date, Minimally Invasive Glaucoma Surgery (MIGS) has the highest4 safety profile.

Type of surgeryAssociated Risks
Trabeculectomy- Loss of vision
- Cataract
- Sight-threatening eye infection (risk can be life-long)
- Bleeding in the eye
- Droopy eyelids
- Persistent eye discomfort
- Eye pressure that is too low
- Failure of surgery with raised eye pressure and glaucoma progression
Glaucoma implant surgery- Loss of vision
- Cataract Infection (unlikely to have life-long risk)
- Bleeding in the eye.
- Droopy eyelids (risk lower than trabeculectomy)
- Eye pressure that is too low
- Failure of surgery with raised eye pressure and glaucoma progression
Minimally invasive glaucoma surgery (MIGS)- Infection (unlikely to have life-long risk)
- Bleeding in the eye
- Droopy eyelids (risk lower than trabeculectomy)
- Failure of surgery with raised eye pressure and glaucoma progression

What are the success rates for glaucoma surgery in Singapore?

Trabeculectomy, glaucoma


  • Risk factors for trabeculectomy failure include pigmented races, the use of multiple glaucoma eyedrops and previous eye surgery

Tube implant surgery

  • Success rates are higher than trabeculectomy in patients with previous incisional surgery[7]
  • While the Baerveldt Glaucoma Implant (BGI) has a higher success rate compared to the Ahmed Glaucoma Valve (AGV), it is associated with a significantly higher risk of hypotony (eye pressure being too low) [8]. Early studies show that the Paul Glaucoma Implant (PGI) has a 93.2%[9] success rate  — similar efficacy to the Baerveldt but with a lower risk of complications.


  • Success rate is dependent on the type of procedure carried out
  • Patients with mild to moderate glaucoma on 1-2 glaucoma medications can achieve at least 20% eye pressure reduction without the need for medication for 24 months [10]
  • However, long term outcomes of MIGS have yet to be ascertained

Regardless of the type of glaucoma surgery performed, regular eye examinations are vital to monitor your eye pressure and glaucoma.

While glaucoma surgery cannot cure glaucoma, it is often successful in reducing your eye pressure and preventing vision loss. Early detection and treatment of glaucoma can preserve your vision, hence I would encourage everyone to go for regular eye screenings as early glaucoma often has no symptoms.

If you have any questions regarding glaucoma or need a second opinion for your diagnosis, please feel free to drop me a message and I am more than happy to help.


  1. National Eye Institute. (2022, January 3). Glaucoma Surgery. National Eye Institute. Retrieved May 5, 2022, from
  2. Schuster, A. K., Erb, C., Hoffmann, E. M., Dietlein, T., & Pfeiffer, N. (2020). The Diagnosis and Treatment of Glaucoma. Deutsches Arzteblatt international, 117(13), 225–234.
  3. Klink, T., Sauer, J., Körber, N. J., Grehn, F., Much, M. M., Thederan, L., Matlach, J., & Salgado, J. P. (2014). Quality of life following glaucoma surgery: canaloplasty versus trabeculectomy. Clinical ophthalmology (Auckland, N.Z.), 9, 7–16.
  4. Otárola, F., & Pooley, F. (2021). Minimally invasive glaucoma surgery (MIGS) devices: risks, benefits and suitability. Community eye health, 34(112), 59–60.
  5. Al-Hazmi, A., Awad, A., Zwaan, J., Al-Mesfer, S. A., Al-Jadaan, I., & Al-Mohammed, A. (2005). Correlation between surgical success rate and severity of congenital glaucoma. The British journal of ophthalmology, 89(4), 449–453.
  6. Cillino, S., Casuccio, A., Di Pace, F., Cagini, C., Ferraro, L. L., & Cillino, G. (2016). Biodegradable collagen matrix implant versus mitomycin-C in trabeculectomy: five-year follow-up. BMC ophthalmology16, 24.
  7. Gedde, S. J., Schiffman, J. C., Feuer, W. J., Herndon, L. W., Brandt, J. D., Budenz, D. L., & Tube versus Trabeculectomy Study Group (2012). Treatment outcomes in the Tube Versus Trabeculectomy (TVT) study after five years of follow-up. American journal of ophthalmology153(5), 789–803.e2.
  8. Christakis, P. G., Kalenak, J. W., Tsai, J. C., Zurakowski, D., Kammer, J. A., Harasymowycz, P. J., Mura, J. J., Cantor, L. B., & Ahmed, I. I. (2016). The Ahmed Versus Baerveldt Study: Five-Year Treatment Outcomes. Ophthalmology123(10), 2093–2102.
  9. Koh, V., Chew, P., Triolo, G., Lim, K. S., Barton, K., & PAUL Glaucoma Implant Study Group (2020). Treatment Outcomes Using the PAUL Glaucoma Implant to Control Intraocular Pressure in Eyes with Refractory Glaucoma. Ophthalmology. Glaucoma3(5), 350–359.
  10. Asia-Pacific journal of ophthalmology (Philadelphia, Pa.)8(6), 436–440.[1] 

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    Dr Chelvin Sng of Chelvin Sng eye center

    Dr Chelvin Sng

    Adjunct Associate Professor
    Senior Consultant Ophthalmologist
    ✓ 4 Gold Medals (Specialist Accreditation Examination)
    ✓ "Top 50 Rising Stars” (2017), “Top 100 Female Ophthalmologists” (2021), "Top 100 Ophthalmologists" (2022) "Top 100 Ophthalmologists" (2023) and "Top 100 Ophthalmologists" (2024)
    ⋆ Global Ophthalmologist Power List (voted by peers worldwide)
    ✓ Cambridge University Graduate with Triple First Class Honours and Distinctions


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