Glaucoma is a degeneration of the optic nerve, which is the main nerve that connects the eye to the brain. The degeneration is related to the pressure in the eye, which may be elevated. The eye constantly produces aqueous, the clear fluid that fills the anterior or front chamber of the eye. The aqueous flows out of the anterior chamber through a complex drainage system. The delicate balance between the production and drainage of aqueous determines the eye’s intraocular pressure. In patients with glaucoma, the outflow of fluid may become restricted, causing the pressure inside the eye to rise. However, some forms of glaucoma have no pressure elevation. If left untreated, glaucoma can damage the optic nerve. Damage to the optic nerve is permanent and will lead to blindness. Lowering eye pressure is the only known effective treatment.

Medical Treatments
Prescribing eye drops is usually the first step in lowering the eye pressure. Some medications reduce the eye pressure by decreasing the production of aqueous. However, because the aqueous supplies nourishment to the front of the eye, the body has a built-in mechanism that limits the extent the eye’s pressure can be lowered with medication. Other medications work by improving the outflow of fluid from the eye. For the maximum benefit, these two types of drugs are often used together. When medications no longer control the eye pressure adequately or cannot be tolerated, surgery may be needed.

Argon Laser Trabeculoplasty (ALT)
ALT is a surgical approach that uses laser to lower eye pressure by increasing the outflow of aqueous. ALT has been performed since the early 1980’s on millions of patients. This relatively painless procedure is performed in the office and requires no surgical incision. There is no risk of infection. This procedure takes 15-20 minutes and does not permanently affect vision. The full effect of ALT takes approximately 3-4 weeks. Recent long-term studies have shown initial success rates to be 75-85% at one year, 50% at 5 years, and 32% at ten years; therefore there is some loss of effect after many years. Residual scarring after this procedure is very rare, with the newer techniques utilized at Clarus. Some types of glaucoma respond to ALT better than others. This may be repeated if necessary. Selective laser trabeculoplasty (SLT) is a similar laser procedure used to lower eye pressure. Current studies indicate success rates comparable to ALT. If laser treatment is not successful, other surgical or medical therapies remain available.

Visocanalostomy
Recent advancements in surgical technique have led to the development of a procedure called viscocanalostomy. This surgery involves accessing an internal canal and injecting a thick visco-elastic fluid in the eye to expand the drainage canal.

This technique allows the aqueous fluid to flow from the front of the eye at a much more controlled rate than with other glaucoma surgeries. Because of this, the eye pressure is much more likely to fall in the desired range after the operation, significantly reducing the risk of an extremely low pressure (hypotony). Another advantage of viscocanalostomy is that it stimulates the body’s healing mechanism less than trabeculectomy, so there is a reduced tendency for scar tissue to form and the eye pressure to rise.

Although viscocanalostomy takes longer for the doctor to perform and requires more skill, it is much simpler for the patient. This procedure can be performed alone or along with cataract surgery. Most patients enjoy a quick recovery following viscocanalostomy compared to other glaucoma surgeries, along with less dependence on medication, fewer postoperative visits, and reduced risk.

Trabeculectomy
A trabeculectomy involves surgically creating a reservoir (bleb) on the top of the eye, usually under the upper eyelid. Aqueous fluid from inside the eye flows into the bleb and then is absorbed. The new drain is entirely inside the eye. The fluid does not enter your tears or flow down your cheek; it is reabsorbed into your blood stream. Although this cannot reverse existing damage from glaucoma, a trabeculectomy may stop progression. Recent advances include the use of 5FU (5 Fluorouracil) or Mitomycin. These drugs are two very powerful “anti-scarring” agents that help the flow at the surgery site. These are either used during or after surgery. Laser treatment and frequent drops may also be used.

After surgery, the vision in your operative eye will be decreased for approximately 4-6 weeks. You will need to use multiple drops at frequent intervals after the surgery. You will also need multiple appointments each week after surgery for approximately 4-6 weeks. The drop frequency and appointment frequency will be determined on an individual basis as you continue to heal after the surgery. In some cases, additional procedures may be necessary to adjust the pressure.

Other Glaucoma Surgeries
If conventional glaucoma surgeries are not successful, or would have a poor chance of success, then more advanced surgeries are available at Clarus. Glaucoma tubes (“shunts”) can be inserted in the eye to improve fluid outflow. Another option is the fluid producing tissue in the eye (“ciliary body”) can be damaged to reduce fluid flow with a laser. These procedures require specialized skills to perform, carry additional risks, and are offered in complex cases, if the need arises.