yulius hermanto
Surgery for Cataract
Link: www.aao.org/
Cataract or clouding of lens, causes blurred vision, and if severe enough could lead to blindness. Cataract has become world leading cause of blindness especially in underdeveloped nations. Thus cataract has significant on human health issues, especially related to the eyes. Most of the cataract related to aging process, with the development of our science and technology in medicine, thus will increase the amount of elderly population. Thus will increase the burden of cataract patients. Besides that, sedentary lifestyle that occurs nowadays also brings health complication such as diabetes mellitus. Diabetes also become a risk factor the development of early cataract.
Well, in conclusion that amount of cataract patients are gonna raise, because the increase amount of elderly population and lifestyle associated disease such as diabetes.
Eventhough cataract has the greatest burden in number of patients but cataract is curable cause of blindness compare to the others causes such as glaucoma, macular degeneration, diabetic retinopathy, etc.
Treatment of Cataract
I already described about the pathophysiology of cataract in my previous article that the process of cataract development is lens protein clumping that being caused by lot mechanisms.
Scientists have found a lot of mechanisms that lead to cataracts, but until now the only effective method of cataract is by surgery.
Cataract surgery is very successful in restoring vision. In fact, it is the most frequently performed surgery in the United States, with more than 3 million Americans undergoing cataract surgery each year. Nine out of 10 people who have cataract surgery regain very good vision, somewhere between 20/20 and 20/40.
Although surgery is the only remedy for cataracts, it is almost never an emergency. Most cataracts cause no problem other than reducing a person's ability to see, so there is no harm in delaying surgery.
Early cataracts may be managed with the following measures:
- Stronger eyeglasses or contact lenses
- Use of a magnifying glass during reading
- Strong lighting
- Medication that dilates the pupil. (This may help some people with capsular cataracts, although glare can be a problem with this treatment.)
Some cataracts develop to a certain point and then stop. Even if a cataract does progress, it may be years before it interferes with vision. Very rarely do people need immediate cataract surgery.
Indications for Cataract Eye Surgery
In general, surgery is indicated for people with cataracts under the following circumstances:
The Snellen eye test reports 20/40 or worse, with a cataract being responsible for vision loss that cannot be corrected by glasses.
Performing everyday activities has become difficult to perform to the point that independence is threatened, or the patient is at risk for accident or injury.
Cataract Eye Surgery
However, whether surgical treatment is appropriate or not further depends on the patient's specific condition and needs. Some examples include:
Even if the criteria for surgery are met, a very sick, elderly person in a nursing home may have less need for sharp vision than an active younger adult. Among very elderly patients (85 years and older), especially those with serious health problems, there are also higher risks for complications during surgery and poor outcomes afterward. Nevertheless, these cautions should not prevent the elderly from having this procedure; vision improvement rates are still over 85%.
Even if the criteria for surgery are not met, some people with eye tests of 20/40 or better might want surgery because of problems with glare, double vision, or the need to have an unrestricted driver's license.
Even if the criteria for surgery are not met, if retinal disease is also suspected, the doctor may perform cataract surgery in order to have a clear view of the eye. Because of the risks, albeit small ones, of poorer vision or blindness, no one should be forced to have cataract surgery if they don't want it or are not strong enough to have the procedure.
Treatment Decisions for Cataracts in the Second Eye. If a person has a cataract in a second eye, the issues for decision making are the same as for the first eye. The timing of the procedure in the case of two cataracts is unclear. Doctors have long recommended postponing surgery on the second eye until the first eye has healed and the results are known. However, many patients have trouble reading and performing ordinary tasks while waiting for a second surgery. Patients with double cataracts should discuss all options with their surgeon.
Cataract Surgical Procedures
All cataract procedures involve removal of the cataract-affected lens and could be continue to replace it with an artificial lens or not, it's depends on the patient's eye conditions.
Phacoemulsification
Phacoemulsification (phaco means lens; emulsification means to liquefy) is the most common cataract procedure performed in the United States.
The procedure generally involves:
- The surgeon makes a small incision usually 3 mm.
- A thin probe that transmits ultrasound is then used to break up the clouded lens into small fragments.
- The tiny pieces are sucked out with a vacuum-like device.
- A replacement lens is then inserted into the capsular bag where the natural lens used to be.
In most cases, this is an intraocular lens (IOL), which is foldable and slips in through the tiny incision.
Because the incision is so small, it is often watertight and does not require a suture afterward, particularly if a foldable lens has been used. A suture may be needed if a tear or break occurs during the procedure or the surgeon inserts a rigid lens that requires a wider incision.
Phacoemulsification requires only local anesthesia. Newer methods for administering local anesthesia produce few complications. Most phacoemulsification procedures now take about 15 minutes, and the patient is usually out of the operating room in about an hour. There is little discomfort afterward, and visual rehabilitation takes about 1 - 3 weeks.
Phacoemulsification is sometimes combined with glaucoma surgical procedures, for patients who have both glaucoma and cataracts.
Extracapsular or Intracapsular Cataract Extraction
Extracapsular cataract extraction, the original standard procedure, is now generally used only in patients who have an extremely hard lens. It typically involves the following steps:
- The ophthalmologist works under an operating microscope to make a small incision in the cornea of the eye.
- The surgeon then extracts the clouded lens through this incision.
- The capsule is left in place, which adds structural strength to the eye and enhances the healing process. (Less commonly in intracapsular cataract extraction, the surgeon removes the lens and the entire capsule. This procedure has greater risks for swelling and retinal detachment.)
- A replacement lens is then usually inserted.
- A small suture is needed to stitch the incision together.
It takes about 2 - 4 weeks to completely restore vision.
Intraocular Lens Replacement
Before the invention of IOLs, cataract patients were treated by lens extraction and using glasses, but the power of glasses in very high known as aphakic glasses. Most of the patients having discomfort using those glasses, because there are side effects of using glasses with high dioptri.
Intraocular Lens
Nowadays, in about 90% of cataract operations, an artificial lens, known as an intraocular lens (IOLs), is inserted. Most IOLs are made out of acrylic, although other materials, such as silicon, are also used.
IOLs are designed to improve specific aspects of vision. The choices include:
1. Lenses that address a single fixed focal point. Such lenses are suitable either for reading or distance vision, but not both. If a distance lens is implanted, the surgeon prescribes glasses or contact lenses for reading. If a reading lens is implanted, lenses for seeing distances will be prescribed.
2. Lenses that address multifocal points. Multifocal lenses can focus at different points for both reading and distance vision. However, contrast may be reduced, and some patients experience glare and halos, particularly at night.
3. Lenses are available that will correct astigmatism after cataract surgery.
Complications of Cataract Surgery
Modern cataract surgery is one of the safest of all surgical procedures. Most complications, even if they occur, are not serious. They can include:
Swelling and inflammation. Risk is about 1%. This complication is particularly harmful for patients with existing uveitis (chronic inflammation in the eye, which can be due to various medical conditions).
Glare. Patients may experience glare after surgery from light scattering at the edges of the new lens, particularly with square-edged IOLs, which are typically used with posterior capsular cataracts. In most cases, this is a temporary problem that resolves after a few weeks.
Materials used in some lenses trigger an immune response in some patients. This causes inflammation and tiny deposits of tissue in the eye that lead to secondary cataracts -- called posterior capsule opacification.
Retinal detachment. In rare cases, the retina at the rear of the eye can become detached. Risk is very low (0.1%), and phacoemulsification poses less of a risk for this than older standard surgery.
Glaucoma. This is an eye condition in which the pressure of fluids inside the eye rises dangerously. Risk is very low, but patients should be sure to avoid activities after surgery that increase pressure.
Infection. This is very rare (0.2%) but may be significant if it does develop.
Blisters on the cornea.
Bleeding can develop inside the eye. Risk is about 1% for minor bleeding and 1 in 10,000 for severe bleeding.
An implanted IOL can become damaged or dislocated. Risk is very low.
The surgery itself can produce vision loss or impairment. The risk for this is 1 in 1,000. (Phacoemulsification poses less of a risk than standard surgery.)
Conclusion
Cataracts is curable cause of blindness, the only effective method for treatment of cataracts is surgery. There are several procedures in cataract surgery, it should choose depends on patient's conditions.
The timing of cataract surgery is the greatest concern, because most of the cataract isn't emergency cases. The important consideration is the visual improvement related to daily activities.
