Glaucoma is a popular eye condition where the optic nerve, which connects the eye to the brain, gets damaged. It's usually as a result of fluid building up in the front part of the eye, which increases pressure within the eye.
Glaucoma can cause loss of vision if it's not diagnosed and treated early. It can affect persons of all ages, but is mainly common in adults in their 70s and 80s.
All glaucoma surgical procedures (whether laser or non-laser) are designed to accomplish one of two primary results: decrease the production of intraocular fluid aqueous humor or increase the outflow (drainage) of the same fluid. Periodically, a procedure will accomplish both.
Currently the goal of glaucoma surgery and other glaucoma treatment is to lower or stabilize intraocular pressure (IOP). When this goal is accomplished, damage to ocular structures — especially the optic nerve — may be avoided.
If medicine or laser surgery does not ease eye pressure, a patient may need glaucoma surgery. There are various options.
Filtering surgery creates a new approach through the eye's tissues to let fluid drain from the eye.
In the most common filtering surgery, called a trabeculectomy or a sclerostomy, the surgeon makes a small hole in the white part of the eye (the sclera) to create a new outflow path. The fluid then flows through the new hole and creates a bleb, which is like a small bubble or pool on the surface of the eye. The bleb holds the fluid while it is gradually absorbed into the surrounding tissue. The upper eyelid normally hides the bleb, so it's not noticeable to you or others.
Some persons who have this procedure no longer need medicine after surgery. Some people treated still need medicine, but they have better pressure control after the operation. Around 15 percent do not benefit from filtering surgery.
An alternative type of glaucoma surgery may occasionally be carried out in which the tissues over the drainage region are thinned but not fully penetrated. This procedure can produce less complication than trabeculectomy, but also may be less effective in achieving low intraocular pressures.
Drainage Implant Surgery
Drainage implant surgery is sometimes carried out when a person is not eligible for filtering surgery or when earlier filtering surgery has failed. Depending on the type of implant used, the surgery is called valve, shunt or seton surgery.
In these procedures, the surgeon inserts a tiny tube through the sclera into the front area of the eye behind the iris. This tube becomes a path for fluid to drain off. The other end of the tube is joined to a tiny reservoir that acts like the bleb to hold fluid until it is absorbed into the surrounding tissue. The reservoir is positioned on the surface of the eye, back between the eye muscles, so it is not visible.
Right after filtering or drainage implant surgery, a person can have a temporary reduction of vision. Vision usually improves over several weeks to its former level. It also takes time to recover from either form of surgery. For example, in the weeks after surgery, people must always avoid getting water into their eyes, reading, bending, lifting heavy objects and driving.
Canaloplasty is a latest procedure to lower pressure that is performed within the eye wall but that does not actually pentrate the eye. While this procedure is safer than filtering surgery, it does not supply as profound a reduction in IOP.
Minimal Invasive Glaucoma Surgeries
Minimal Invasive Glaucoma Surgeries are a set of newer FDA approved operations that reduces pressure. These methods currently include Trabectome and the iStent. Both of these approaches work by bypassing the blockage in the drain of the eye to aid fluid flow through the natural drain and do not need "artifical" pathways for fluid drainage to regions outside the eye. Like canaloplasty, the procedures are less risky than filtering surgery but do not supply as profound a reduction in IOP. More long-term data is required to determine how well they work beyond the first early years. Use of Minimal Invasive Glaucoma Surgeries is still being debated among glaucoma specialists but can have application that is specific patients.
Laser Cyclophotocoagulation is used for intense cases of glaucoma. It removes tiny areas of the ciliary body that make aqueous fluid. This "turns down the faucet." Laser cyclophotocoagulation need a numbing block to the eye to prevent pain with the procedure.
Risks of Glaucoma Surgery
Glaucoma surgeries have some possible risks, such as:
· A higher risk of getting cataracts
· Infection or leaking of the incision
· Too low pressure
· Hemorrhages inside the eye
Unfortunately, the new drainage path can close, leading to pressure in the eye to rise again. Filtering surgery can be repeated with good outcomes. Also, drainage implants are usually successful in patients whose filtering surgery has failed. The medicines that reduce inflammation and control scar formation after surgery have assisted in increasing the success of glaucoma surgeries.
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