Is Glaucoma Surgery Dangerous?

When medications and laser surgery do not appropriately reduce eye pressure, doctors usually recommend an invasive surgery called filtering microsurgery.

In filtering microsurgery, a tiny hole is created in the sclera through a procedure called sclerostomy. This hole allows fluid to move out of the eye into a filtering bleb that forms below the conjunctiva resulting in decreased pressure in the eye. This decreases and even at times prevents widespread damage to the optic nerve.

Studies suggest diligent followup for at least a period of one year. In the elderly population, the filtering surgery is believed to have a success rate of about 80% in most of the cases for a minimum of a year.

Consequently, the hole created starts to close up and the pressure starts to increase again. This is due to the body’s attempt to heal the tiny hole created during surgery. The process is faster in young people due to strong immunity. Drugs that prevent wound healing like 5-FU and mitomycin C slow the healing rate of the hole. If necessary, it is possible to perform filtering surgery for glaucoma several times in an affected eye.

In some cases there are complications that can be mild, moderate or severe. They can occur in perfectly performed surgeries by the most experienced surgeons.

The most serious risk, as in any eye surgery, is the definitive loss of vision. This is uncommon but it is not impossible. In the particular case of glaucoma, this risk depends on the type of glaucoma and the stage of evolution in which it is found, in addition to the complications inherent to surgery. For example: All eye surgery has a shared risk: intraocular infection or infectious endophthalmitis. Many complications can be resolved either during surgery or with new surgeries and/or medication. A definitive deterioration of the vision may result as a consequence. No one can guarantee you a successful surgery.

This is a partial list with the most serious and/or the most frequent complications:

Failure of Drainage of Aqueous Humor (Uncontrolled Pressure): It may be due to internal obstruction of the pathway created in the surgery or by an excess of scarring that blocks the filtration blister created on the surface of eye (11 to 13% of operated patients). It may be necessary to complement the surgery by releasing the scar barrier and/or perform injections on the surface of eye or apply laser impacts. Certain cases require a new surgery.
Intraocular Hemorrhage: It can occur both in the anterior part of the eye – 5 to 10% – (hyphema) as in the posterior part (suprachoroidal hemorrhage). In general, they resolve spontaneously or with medication but certain cases may require a new surgery to drain the blood.
Acute Eye Pressure Increase: Certain postsurgical cases require a new surgery (“Malignant glaucoma”)
Very Low Ocular Pressure: Depending on the cause, it may be resolved with medication or eventually require a new surgery. It can generate a problem in the central part of the retina with a deterioration important vision (hypotonic maculopathy).
Infection Within The Eye (Infectious Endophthalmitis): A characteristic in glaucoma is that the infection can not only occur in the immediate postoperative period, but also several years after surgery.

Also among the complications are that the glaucoma reappears; since the possibility of the duct closing over time, there may also be ocular hypotonia, worsening of vision (cataracts could appear) and eye injuries.

Conclusion

Within a few days after surgery, the ophthalmologist will need to control eye pressure. The doctor will also look for signs of infection or increased inflammation, in some particular cases it will be necessary medication.

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Is Glaucoma Surgery Dangerous?