SURGERY - Questions and Answers with Drs. Bindlish, Kherani, and You

I need glaucoma surgery, what are my options?

There are a few types of glaucoma surgeries:

Minimal Invasive Glaucoma Surgery (MIGS), such as iStent, Hydrus, Kahook Dual Blade, goniotomy, and iTrack advance, is typically reserved for milder disease and has a synergistic effect when combined with cataract surgery. MIGS tends to have a less strong pressure-lowering effect but is generally considered to be safer than the options below.

Minimal Invasive Bleb-forming Surgery (MIBS), such as Xen gel and Preserflo, are subconjunctival drainage devices known for their moderate to high efficacy and lower risk profile compared to trabeculectomy.

Tube shunts, such as the Ahmed Glaucoma Valve, Baerveldt Glaucoma Implant, Ahmed ClearPath Shunt, and trabeculectomies, are recommended for advanced disease with poorly controlled intraocular pressure or refractory conditions despite surgery. Trabeculectomy is generally considered the most effective surgery for lowering intraocular pressure, but it also has a lower safety profile compared to other surgical options.

Your doctor will evaluate your specific condition alongside the risks and benefits of different surgical options before deciding with you on the appropriate procedure.

My father was diagnosed with glaucoma more than 5 years ago and has been treated with eye drops. What are the benefits of having surgery rather than continuing with eye drops?

There are many types of glaucoma surgeries available with variable efficacy and safety profiles. Generally speaking, benefits of surgery are lower eye pressure, less eye pressure variability and possible discontinuation of eye drops. Risks include bleeding, loss of vision, infection and failure over time.

If your father is tolerating his eye drops well and his disease is stable, we generally recommend continuing with the medical drops or lasers. If his eye pressure becomes poorly controlled or he requires eye surgery for another condition (e.g., cataract), then glaucoma surgery can be considered at that time.

How long does the eye take to properly heal after Trabeculectomy surgery?

The recovery process for a trabeculectomy is about eight to ten weeks. (There really is no “healing” process involved as “healing” would indicate that the operation has stopped working and wasn’t a success.)

Is there anything I should do after eye surgery?

After laser treatment, make sure you understand and follow your doctor’s instructions for using eye drops. Depending on the type of surgery you underwent, recovery time can be up to six to eight weeks or longer. During recovery, you should avoid any bending, heavy lifting, or strenuous physical activity. Also avoid swimming until your doctor advises that you can.

Does the healing process differ depending on the age of the patient?

Age can affect recovery. Younger patients tend to recover faster than older patients. Other issues such as previous eye medication use, quantity of medications and duration of use, and smoking can also affect recovery rates.

If further surgeries are required within a short period of time what concerns should the patient be aware of?

After surgery, your doctor may perform additional in-office procedures to care for the surgical site and maintain its function. For instance, your ophthalmologist may need to cut a stitch, inject medications, or “needle” the surgery site. Requiring a secondary surgery is rare.

I was diagnosed with glaucoma and had trabeculectomy surgery two weeks ago. I have been told that I might need another surgery, is this common?

It is uncommon to need a second surgery so quickly after a trabeculectomy which lowers eye pressure by making a window on the eye to bypass the eye’s internal drain. After surgery this window may be “too open” or “too closed” resulting in very low or very high eye pressure. If this persists, another surgery may be required to correct this.

How successful is a trabeculectomy and how long does it take to determine if the surgery was a success?

The rate of success for a trabeculectomy is 80% at 5 years. Anytime during the post-operative period, the surgery may stop working. Post-op care, with frequent visits to the surgeon, is critical for success.

The rate of complications is less than 2%. Common complications include bleeding, infection, or loss of vision. Long term complications include failure – elevated eye pressure, too low eye pressure, or infection.

How long does it take for vision to return after a trabeculectomy? If it doesn’t totally return, can the lens be replaced as with cataract surgery?

It is not uncommon for vision to be blurry for 8 to 10 weeks after surgery, especially if you are still taking steroid eye drops such as prednisolone or Maxidex.

Also if your eye pressure is a little on the low side that can cause the blurry vision.

Once the lens of the eye is replaced after cataract surgery, it is rarely ever replaced again. Later on you may benefit from a YAG Capsulotomy laser to polish the lens.

What should the normal eye pressure be a year after surgery for glaucoma?

There is no such thing as normal pressure.

To treat glaucoma, doctors set individualized targets where they hope no further glaucoma damage to the optic nerve or visual field will occur. The more glaucoma damage, the lower the target.

Will a trabeculectomy work if one has sleep apnea?

Sleep apnea has no effect on a trabeculectomy. A potential issue might be that the pressure of the sleep apnea mask on the face could put undue pressure on the eye and cause damage.

Studies have been inconclusive and contradictory about an association of sleep apnea with glaucoma progression.

My father had glaucoma surgery one month ago, but his eye pressure is still not controlled. What should I do?

Unfortunately glaucoma surgery does not always work the first time or in some people. Sometimes though, over time, the pressure may continue to lower so I would not be too concerned yet. Further treatment may include restarting eye drops, revising the existing surgery or doing more surgery.

In spite of treatment, my condition has progressively deteriorated. Because of persistent high IOP in my right eye (5% central tunnel vision), my doctor has recommended a trabeculectomy. Would it be better to continue applying eye drops rather than risk losing my residual vision from surgery?

Lowering the IOP is the best way to slow the course of glaucoma. Because of the advanced nature of your right eye, the lower the pressure, the better.

If drops or laser treatment haven’t lowered the pressure to a target IOP, the next best option is surgery. Losing the remaining 5% due to a post-operative pressure elevation is a rare complication.

If you continue with the drops only, you may eventually lose the remaining 5% due to the high eye pressure.

My mother has had glaucoma for more than 20 years. She has lost one eye, a great deal of her peripheral vision, and has not responded to laser treatment. Her doctor has recommended an Ahmed Valve implant. What is this?

An Ahmed Valve, or glaucoma drainage valve, is a device that is used to help lower intraocular pressure when maximum medical therapy with eye drops and laser treatment is not enough.

A tube is surgically inserted into the front part of the eye allowing the aqueous fluid from inside the eye to slowly drain through the tube and into the reservoir which is placed on the outside of the eye under the conjunctiva. The fluid is then naturally absorbed by the surrounding tissue.

The slow drainage of fluid decreases the internal eye pressure.

I have glaucoma and need cataract surgery but am worried about the risk of infection.

The overall risk of infection after cataract surgery is less than 1%. Having glaucoma does not increase that risk. Managing dry eyes, blepharitis, and ocular surface disease pre-op may lower your overall risk of infection. Talk to your surgeon about this.

The greatest risk of infection after glaucoma surgery is with a trabeculectomy due to bleb formation.

Minimal invasive glaucoma surgery (MIGS) such as iStent is minimally invasive – usually through the cataract incision – and does not increase the risk for infection. Because there is no bleb formation, there is no increased risk afterward.

I had glaucoma surgery after which my doctor prescribed atropine. Two months later, I was diagnosed with posterior synechiae with large pupil and I cannot read. Is it common to have pain and pressure three months after surgery?

Prolonged inflammation can happen after any surgery and can be a reason for pain.

Dry eyes can also cause pain, so consider lubricating your eyes with artificial tear drops.

The difficulty reading is due to the dilated pupil and peripheral synechiae. It may take some time for the effect of the atropine to wear off, so you may want to try using reading glasses. If the condition persists, your doctor may refer you to an anterior segment surgery to decrease the size of your pupil.

I have glaucoma in one eye that required surgery. Post-surgery, I’ve had difficulty seeing close-up and far away. This was confirmed on the visual field test. This problem was not present before the surgery. Is this normal?

It appears that the glaucoma is advanced in the operative eye and likely the eye pressure was deemed too high hence the need for surgery. It would be important to rule out other ocular conditions such as macular degeneration but vision loss can occur with glaucoma surgery or continue despite surgery.

Are there any specialists in southwestern Ontario experienced in performing trabectome surgery?

There is currently no one in southern Ontario who does trabectome surgery. Other surgical options, including iStent and Xen implants, may be available in London and Kitchener.

What is an iStent? How does it work?

An iStent is a small titanium device that can be implanted in the eye’s internal drain to help it drain more. Some glaucoma patients may be candidates for iStents during cataract surgery.

iStents are indicated for early, mild to moderate, open angle glaucoma. They may eliminate one or more glaucoma drugs. Their main limitation is cost, as not all hospitals can afford this device.

TV news reported on a new technique – placing a small stent in the eye to relieve pressure build-up. How do I go about getting my mother evaluated for this new treatment by a surgeon experienced in this procedure?

Talk to your mother’s doctor for a referral to a surgeon doing iStents. Your mother needs to be evaluated to see if she is a candidate for the surgery. It is indicated for early, mild to moderate glaucoma and may eliminate one or more glaucoma medications. The evaluation will examine the status of the internal eye drain, whether it is open or closed, and the amount of glaucoma present – mild, moderate, severe.

It is best to combine iStent insertion with cataract surgery. The biggest issue is the cost of $600 per stent and over $1,000 for a package of three stents. Currently, the Ontario Health Insurance Program does not cover this cost, so it may not be available in some hospitals. Different Canadian provinces and countries may have alternative coverage and tariffs. You can explore them with your eye specialist.

I have moderate to advanced glaucoma. My doctor is recommending surgery. Is it harmful to smoke marijuana? Will it help eye pressure control or affect future surgery?

Avoid smoking marijuana. It lowers eye pressure but only for a short period of time. You would have to constantly smoke in order to keep your eye pressure low and then the health risks, especially of lung cancer, are great. Smoking marijuana post surgery can jeopardize the surgical outcome — you may be at higher risk of failure due to scarring.

Do you know why an eye will not freeze?

It is uncommon for freezing (topical anaesthesia) not to fully take. However, in some patients topical anaesthetics don’t work that well. This may be because the eye is hypersensitized from medications or previous surgeries. Also eyes that tear excessively may wash out the anaesthetic drops.

An injection around the eye is sometimes necessary to control any discomfort, and for surgery, a general anaesthetic may be better.

Should I have LASIK surgery if there is glaucoma in my extended family or will this make treatment of glaucoma more difficult if needed in the future?

Glaucoma runs in families with highest risk when parents or siblings have it. If it’s in the extended family, the overall risk of getting glaucoma is low. It can skip generations.

LASIK thins the cornea. Your doctor may underestimate eye pressure in a thinner cornea and miss a glaucoma diagnosis. To get a specific correction factor for eye pressure for the future, get a series of eye pressures measured over the course of the day before and after LASIK.