In the past, eye doctors did not often recommend glaucoma surgery as initial treatment, but this has changed somewhat. The general principle of glaucoma surgery is to let aqueous humor leak out of the eye through a hole created at the junction of the colored and white part (where the iris meets the sclera) under the covering layer called the conjunctiva. The chief reason to avoid surgery was pretty obvious and often expressed in plain English by patients: “you can’t go blind from eye drops, but you can with surgery”. As surgery complications decreased over the years, and as we recognized that patients preferred the idea of eye drops, but didn’t take them at an ideal rate, some argued that surgery first had a strong argument in its favor.

A large controlled study (the Collaborative Initial Glaucoma Treatment Study: CIGTS) then randomly assigned volunteer, new open angle glaucoma patients to take either eye drops or have trabeculectomy glaucoma surgery, which is the gold standard procedure (see section Operations for glaucoma). Ten years into the study, both groups were doing well, and those who got surgery in both eyes were, if anything doing slightly better at preserving their visual field test results. Indeed, as shown in other studies, one can get the eye pressure to fall really low with trabeculectomy. But, 20% of operations had failed within the first year. And as with drops and laser, a small percentage of early successes lose pressure control every year that we follow the patient.

The risks of surgery can be generally grouped into the bothersome and the dangerous. Among the former, patients who have the surgery have minor to modest feelings on the eye that are like a gritty sensation or a feeling as if something is in the eye off and on. Most often, these get better quickly. For 1-2% of patients, the feeling in the surgical area is too troublesome and revision surgery is done to relieve it. More serious problems include developing so low an eye pressure that vision is poor, requiring revision surgery to raise pressure in about 3% of operations. Infections happen early after surgery in one per thousand eyes, and over time, there is a continued chance that the area of surgery makes the eye more susceptible to later infection requiring intensive treatment, revision surgery, and rarely, severe vision loss. Cataract (hazy lens) occurs more often after glaucoma surgery. In fact, there is evidence that all of the glaucoma treatments speed up the development of cataract. While this is undesirable, cataract is surgically removable.

At present, more patients choose eye drops than laser or surgery as their first glaucoma treatment. Yet, the CIGTS study found that those with serious glaucoma damage did as well or better with first surgery than the comparison group who took eye drops first. Patients who find laser or surgery to be a good first choice are people who can tolerate a bit higher risk, as well as those who feel that they are generally not good at remembering to take medication. Surgery is a good option, then, for those who would like to have the treatment that most allows them to “forget about” their glaucoma.