Surgical Treatment of Glaucoma
This operation is used to treat glaucoma by creating a new channel, through which fluid drains. This channel drains fluid from inside the eye into a shallow pocket just under the skin on the white of the eye. From there it soaks away into the bloodstream. This additional drain reduces the pressure inside the eye and helps to protect the optic neve from further damage.
The operation takes only half an hour or so, and can be performed under local or general anaesthesia. Afterwards you will be given drops to use, initially eight times a day. I will need to see you frequently over the first few weeks and months. During this time, I will adjust your eye drops and sometimes to carry out very minor procedures in outpatients, to help to maintain the right level of flow though your new drain.
The iStent® is a new device which bypasses the trabecular meshwork, to deliver fluid directly from the anterior chamber (the space infront of the iris and behind the cornea) to the collector channel that circles the edge of the cornea. The trabecular meshwork is thought to be the principle site of blockage in patients with open angle glaucoma.
The iStent® can be used in conjunction with cataract surgery, where it helps to reduce the IOP with almost no additional risk compared with caract surgery alone. This makes it a good option for patients with glaucoma who are planning to undergo cataract surgery. It can also be used in eyes which have previously had cataract surgery.
Typically, the pressure reduction with this procedure is equivalent to the effect of using one or two types of eyedrops. The long-term outcomes of this device are not yet known, but the early results are promising.
The iStent® is useful in mild to moderate glaucoma. It reduces the pressure by a smaller amount than a trabeculectomy would, and may not be effective for as long, but the procedure carries a lower risk.