|
Over the past thirty years Laser Eye Surgery has undergone
unprecedented technological change, evolution and in many cases, revolution.
This has allowed the development of treatment options for common vision
problems, such as nearsightedness, farsightedness and astigmatism, and complex
eye diseases such as diabetic retinopathy and glaucoma, that were simply not
possible using conventional ophthalmic surgery. These Laser Eye Surgery
developments have not only brought new treatment options, but in most cases have
brought better outcomes in terms of patient quality of life through preservation
and enhancement of vision.
With over one million LASIK procedures being performed each
year, LASIK is the most frequently performed Laser Eye Surgery in the United
States today. In general, when one thinks of Laser Eye Surgery, they first think
of LASIK.
Laser Eye Surgery for Diabetic Retinopathy
Diabetic Retinopathy is a sight threatening complication of
systemic diabetes mellitus. Background Diabetic Retinopathy (BDR) may occur at
any point in time after the onset of diabetes. In general, this is the first
"stage" of diabetic retinopathy and, therefore, the least concerning. Early on,
this condition is often present without any visual symptoms but is characterized
by the retina displaying dot and blotch hemorrhages, microaneurysms and exudates
or leakage from the fine blood vessels.
During this stage which may also be called Non Proliferative
Diabetic Retinopathy (NPDR), it may lead to the formation of macular edema, or
retinal swelling. Sometimes this condition will result in decreased and or
distorted central vision. If there is clinically significant macular edema or
swelling of the macula as a result of the leaky capillaries and microaneurysms
in the retina laser eye surgery may be indicated in order to restore and
preserve vision. Ophthalmologists apply very rigid criteria in order to
determine who should have the laser eye surgery procedure called, Focal Laser
Photocoagulation . These strict guidelines have been developed after many years
of clinical trials and protocols in the Early Treatment Diabetic Retinopathy
Study (ETDRS) in conjunction with the National Institutes of Health.
In its later stages, called Proliferative Diabetic Retinopathy
(PDR), laser eye surgery become an even more important option. Proliferative
Diabetic Retinopathy (PDR) carries a significant risk of visual loss. PDR is
characterized by the development of new blood vessel growth or
"neovascularization". Unfortunately, the neovascular vessels are fragile and
have a tendency to break and bleed into the vitreous body in the back of the
eye. In addition to sudden vision loss, this may lead to more permanent
complications, such as retinal detachment and neovacular glaucoma. Thus, the
elimination of neovascularization with laser eye surgery is an important
treatment option.
Patients with proliferative diabetic retinopathy are often
treated with the laser eye surgery procedure called scatter laser
photocoagulation of the peripheral retina. The sooner the treatment is applied,
the better. This laser eye surgery technique is also called Pan Retinal Laser
Photocoagulation or PRP. By using the laser to stop and hopefully reverse the
formation of the neovascularization Ophthalmologists are able to lessen the
chance of significant vision loss. As with most types of laser eye surgery, Pan
Retinal Photocoagulation is performed as an in-office or out-patient procedure.
The actual laser eye surgery treatment usually 30-45 minutes per session. To be
most effective Pan Retinal Photocoagulation often requires 3-4 individual
treatment sessions. Thus laser eye surgery options for treatment of diabetic
retinopathy include focal laser photocoagulation for macular edema and pan
retinal photocoagulation for neovascularization.
Laser Eye Surgery for Age Related Macular
Degeneration
Age Related Macular Degeneration (AMD) occurs in two primary
types. Dry AMD that accounts for approximately 90% of cases and is generally the
milder form of the disorder and is not amenable to treatment with any form of
currently FDA approved treatment. Wet AMD, the second type is by far much more
sight threatening but fortunately only accounts for approximately 10% of cases.
Wet Age Related Macular Degeneration is treatable with certain types of laser
eye surgery if it is diagnosed early enough.
Wet Age Related Macular Degeneration can sometimes be treated
with one of two types of laser eye surgery. Traditional AMD laser eye surgery
called Focal Laser Photocoagulation can use either the Argon Laser of the Diode
Laser to thermally destroy blood vessels. The FDA recently approved a more
advanced laser eye surgery technique called Photodynamic Therapy.
With Photodynamic Therapy a unique light activated dye called
Visudyne is injected into your arm so that it circulates and fills the
neovascularization beneath the retina. An Ophthalmologist then applies a non
thermal red laser which activates the Visudyne molecules so that they seal and
reduce the unhealthy blood vessels.
In order to be a candidate for either Focal Laser
Photocoagulation or Photodynamic Therapy you must first have a specialized
diagnostic test called a fluorescein angiogram or indocyanine angiogram in order
to determine whether there is the presence of subretinal neovascularization that
is also called a choroidal neovascular membrane. As with diabetic retinopathy,
the neovascularization is fragile and tends to break and bleed causing a scar.
If the subretinal neovascularization is outside the macula it can be treated
with either Focal laser photocoagulation or Photodynamic Therapy. If the
neovascularization occurs within the macula, most Ophthalmologists would only
consider using Photodynamic Therapy.
Laser Eye Surgery for Age Related Macular Degeneration aims to
obliterate the subretinal neovascular membranes that form prior to their
bleeding so as to prevent bleeding and scar formation. Once bleeding has
occurred, laser eye surgery for AMD is not usually useful.
Laser Eye Surgery for Glaucoma
Glaucoma is an eye disease that is typically associated with
pressure in the eye that results in damage to the optic nerve and ultimately
vision loss. Glaucoma is usually a disease in which patients have no real
symptoms until its late stages. In reality glaucoma is a group of optic nerve
diseases. In fact there are many types of glaucoma, some of which are
particularly well treated with different types of laser eye
surgery.
- Primary Open Angle Glaucoma
Primary open angle
glaucoma (POAG) is the most common of all types of glaucoma. Patients are
usually treated with eyedrops and sometimes with oral medications first. If the
eyedrops or oral medication do not control the pressure in the eye, laser eye
surgery may be the best treatment option. Some Ophthalmologists now prefer to
use a type of laser eye surgery called Argon Laser Trabeculoplasty (ALT) as a
first step either before or along with medications.
- Angle Closure Glaucoma
Angle closure glaucoma
occurs because of poor anatomy of the space between the cornea and iris, called
the trabecular meshwork. This meshwork is the area where aqueous fluid drains.
If the space or angle is too narrow it will block the drainage and cause angle
closure glaucoma.
A laser eye surgery procedure called a laser iridotomy
in which a laser is used to create a small opening or hole in the iris that
allows the aqueous fluid to drain.
- Normal Pressure Glaucoma (Low-Tension
Glaucoma)
Normal pressure glaucoma, also known as low-tension glaucoma,
occurs in approximately one-third of all patients afflicted with glaucoma. This
type of glaucoma results in the same type of damage to the optic nerve and
creates the same type of vision loss but patients are not found to have high
pressures. It is believed to be the result of poor pressure in the blood vessels
that nourish the optic nerve. While some Ophthalmologists may use eyedrops to
treat this type of glaucoma, others suggest the laser eye surgery technique
called Argon Laser Trabeculoplasty (ALT) in order to avoid the side effects and
costs of medications.
- Pigmentary Glaucoma
Pigmentary glaucoma is a form
of glaucoma that usually presents in young males, 20 to 50 years old who are
nearsighted and of African-America heritage. Pigmentary glaucoma is caused by
chaffing of the iris as it rubs against the structures supporting the lens in
your eye. This releases pigment that obstructs the flow of aqueous and causes
the pressure in the eye to rise. Pigmentary glaucoma has the best response to
the laser eye surgery procedure Argon Laser Trabeculoplasty (ALT) of any type of
glaucoma.
- Neovascular Glaucoma
Neovascular glaucoma is a form
of glaucoma that most commonly occurs in conjunction with Proliferative Diabetic
Retinopathy or after a Central Retinal Vein Occlusion that results in
neovascularization. The new blood vessels can actually block the drainage of
fluid from the eye. Laser eye surgery to obliterate the new vessels on the
surface of the iris is not effective. However, when the patient has a Pan
Retinal Phtotocoagulation for the retinal neovascularization, often the iris
vessels will regress and the pressure will normalize. If that does not produce
the desired results, a laser eye surgery procedure called Laser
Cyclophotocoagulation, can be used to obliterate part of the ciliary body so
that it no longer produces fluid.
Thus, there are many types of glaucoma. The information
provided is an overview of those types of glaucoma that may be successfully
treated with various types of laser eye surgery. In addition there are two other
types of laser eye surgery that have come into recent favor for the treatment of
glaucoma. Endoscopic Cyclophotocoagulation (ECP) allows the laser surgeon to
view the ciliary body through an endoscopic camera and apply the laser energy to
treat the ciliary body so it reduces or stops the production of fluid. Selective
Laser Trabeculoplasty (SLT) is a method of laser eye surgery that allows the
laser surgeon to only obliterate very specific target cells in the trabecular
meshwork, increasing the ability of the meshwork to drain the aqueous fluid and
thus reducing pressure. These laser eye surgery techniques are growing in use
and will hopefully prove themselves over time.
Laser Eye Surgery for Cataracts
Modern cataract and lens implant surgery is one of the most
successful surgeries that can be performed today. Cataracts are removed using an
advanced technique called phacoemulsification whereby the cataract is broken
into small pieces and gently suctioned through a tiny incision. In about 20% of
patients, the membrane that is left in place to help support the intraocular
lens implant may become hazy or cloudy. This may cause the vision may be
blurred, hazy, or can cause glare. This is not a recurrence of the cataract, as
once they are removed they never return. Fortunately this hazing or cloudiness
of the membrane, which is called the posterior capsule, is easily treatable with
laser eye surgery and nearly always restores or improves vision. The laser eye
procedure called a Yag Laser Capsulotomy or "Yag" is performed right in the
Ophthalmologist s office with just a few drops to make you more comfortable.
The improved visual results are virtually immediate.
Laser Eye Surgery has indeed opened up the possibilities for
patients to reduce their dependence on eyeglasses and contact lenses with LASIK
as well as preserve their vision through advanced treatment options for diabetic
retinopathy, age related macular degeneration, glaucoma and cataracts.
|
