Glaucoma is a disease that affects the optic nerve of the eye, causes the patient’s vision to be gradually lost and if it is not detected in time, it will continue its progressive evolution until causing irreversible blindness. This condition can affect anyone, however, it increases the risk in adults over 45 years of age, people with diabetes, patients who suffer from migraine headaches and those who have relatives with glaucoma.

Surgical intervention is suggested when the patient is intolerant to medical treatment for glaucoma or it is insufficient to prevent the progression of glaucoma.

To surgically treat this ocular pathology, there are different techniques and it is up to the ophthalmologist to recommend the most appropriate for each case.

How is Treatment for Glaucoma surgery?

All glaucoma surgery techniques are normally performed under local anesthesia, that is, applying anesthesia to the eyeball. Thus, the patient is awake and conscious at all times, but does not experience any pain during glaucoma surgery. The anesthetist also provides sedative drugs to keep the patient calm.

Types of treatment for Glaucoma surgeries

Filtering glaucoma surgery

This is the most widely used surgical technique, and it is so called because it is trying to create a drain or fistula that allows the intraocular fluid or aqueous humor to escape unhindered into the subconjunctival space.

Commonly the most applied is Trabeculectomy. As well as the least invasive that is the deep non-perforating sclerectomy (EpNp).

Trabeculectomy is performed a small opening at the level of the anterior part of the eye, producing a direct communication of the intraocular space with the subconjunctival.

While non-perforating deep sclerectomy (EpNp) consists of the extraction of a portion of ocular tissue, leaving the deepest part intact, that is, a penetrating procedure is not performed inside the eye. This part, barely a few microns thick, acts as a filter; allowing the intraocular fluid to escape in a more controlled and progressive manner.

Each patient, depending on the characteristics of their glaucoma and the anatomical aspects of their eyeball, will need one type of glaucoma filtering surgery or another.

The Express Implant

This is an intermediate procedure. It is a thin tube that is inserted in the anterior part of the eye and allows the drainage of HA (aqueous humor) from the interior of the eye into the subconjunctival space.

Aqueous humor drainage devices

These devices are reserved for more advanced cases of glaucoma, in which a previous filtration technique has failed, or if this is not possible due to the characteristics of the eye.

They consist of a tube that is inserted into the anterior part of the eye, where the aqueous humor (HA) is drained. The intraocular fluid drains into the body of the device and is lodged under the upper eyelid, so it is not visible from the outside.

Types of aqueous humor drainage devices

There are two types of drainage devices: valve and non-valve.

Valved devices have a valve system that limits, to some extent, the output of HA when a certain level of intraocular pressure is reached. Therefore, they are easier to use since they start working immediately.

The non-valved ones do not have this mechanism, therefore, being an “open tube”, they need to be occluded during the first weeks to avoid a sudden “drainage” of the eye. However, they have been shown to be more effective in different comparative studies. These types of devices produce a greater and more sustained decrease in intraocular pressure, although they require more maneuvers to avoid ocular hypotonia.

Diode laser transscleral cyclophotocoagulation

This procedure is performed in cases of advanced treatment for glaucoma in which the rest of the surgeries have failed. No surgical intervention is performed as such, as no incision is made in the eye tissues.

It consists of the application of a laser probe on the entire circumference of the eye on the outside, in order to coagulate the ocular structures responsible for the production of the internal fluid of the eye and reduce intraocular pressure.

MIGS techniques (Minimally Invasive Glaucoma Surgery)

These are a type of techniques that have been appearing in recent years. They consist of the intraocular introduction of implants that are much smaller than those used in other types of glaucoma surgery.

Given the small size of these implants, this surgery is characterized by being minimally invasive inside the eye and by its high safety profile. They are surgeries that are performed in less time than the conventional ones and the complications that they can cause are, in general, of a mild nature. This makes them lose a bit of effectiveness when compared with the traditional surgical techniques described in the previous paragraphs.

However, there are different types of MIGS implants, and some of them, used in appropriate cases, produce a decrease in intraocular pressure that is very comparable to filtering techniques.

Furthermore, as we have already seen, the medical treatment of glaucoma is not without complications. Therefore, this surgery is more convenient for the patient, especially because it is very efficient to combine it with cataract surgery, since it causes very little postoperative inflammation, and allows a faster visual recovery.

Care after glaucoma operation

After glaucoma surgery, it is important to rest for about a week. If the patient has undergone MIGS surgery, she will be able to perform more activities earlier than with the other techniques.

The patient should use anti-inflammatory eye drops and antibiotics during the first 2 to 3 months after surgery for glaucoma. The ophthalmologist will modulate the type of treatment for glaucoma depending on the evolution of each patient.

After Glaucoma Surgery

• A small lump can be seen that corresponds to the filtration blister made during surgery and is completely normal.
• It is important not to make sudden movements with the head, to make efforts and to limit the movements.
• It is recommended not to do sports activities during the first postoperative month.
• It is normal for the eye to be red, sore or watery, blurred vision and a change in the graduation.
• It is recommended not to fatigue the eye trying to read during the first postoperative days.

It is also possible that, after a glaucoma intervention, a cataract progressively develops. This will happen with greater probability the more invasive the technique used has been.