When the lens of the eye is clouded with protein lumps, it forms a smoky screen called a cataract. A cataract tends to grow larger over time and cloud most of the eye's natural lens. Due to the cloudiness, the lens is not able to transmit clear pictures to the retina and vision is affected. Age-related cataracts are the most common type of cataracts that are observed. A nuclear cataract is formed in the center of the lens and is part of the natural aging process. A cortical cataract develops in the lens cortex and gradually extends towards the lens. This is noticed largely among patients suffering from diabetes. They are also likely to develop subcapsular cataract that forms at the back of the lens. Some babies are born with congenital cataracts. Secondary cataract develops as a result of diabetes or other diseases or medications. Cataract does not spread from one eye to the other and does not cause permanent blindness.
A person suffering from cataract will notice slightly blurred vision. Most of the symptoms of cataract depend on the type of cataract that has occurred. While a patient suffering from subcapsular cataract may not notice any symptoms, a nuclear cataract can give rise to a temporary improvement in vision followed by worsened condition. Symptoms associated with cataract are blurred vision, light sensitivity and poor night vision. The cloudiness over the lens depends on the amount of cataract and its location. If it is near the center of the lens, vision is badly affected. A patient suffering from cataract may not be able to notice colors brightly and may complain of double vision.
Cataract surgery is the only treatment for cataracts. It has a high success rate in restoring good vision to cataract patients. Ophthalmologists are of the opinion that long-term unprotected exposure to sunlight's UV rays may be a cause for formation of cataracts. Other risk factors include cigarette smoke and air pollution. Eating a diet high in antioxidants, vitamins C and E may play a role in keeping cataracts at bay.
Cataract surgery has made extraordinary and exciting advances over the past 20 years. Last year, approximately 2.7 million Americans underwent cataract surgery. Greater than 95% of those patients now enjoy improved vision. State-of-the-art cataract surgery is now a safe, effective, and comfortable procedure performed almost exclusively on an outpatient basis.
Most cataract surgeries are now performed using microscopic size incisions, advanced ultrasonic equipment to fragment cataracts into tiny fragments, and foldable intraocular lenses (IOLs) to maintain small incision size. Cataract surgery today is the result of extraordinary technological and surgical advancements that allows millions of people to once again enjoy crisp and clear vision. A true marvel of modern medicine, cataract surgery may restore vision to levels you may have never thought possible.
When a cataract is removed, it is replaced with an artificial intraocular lens (IOL). There are a variety of IOLs that can be used in cataract surgery, and they each have their own set of advantages and disadvantages. No single IOL works best for everyone, and only your ophthalmologist can determine the most appropriate IOL for your needs. The FDA approval process for IOLs is among the most rigorous in the world. You can rest assured than any IOLs used in the U.S. have undergone very extensive testing for safety and efficacy. These same IOLs are also used for a refractive surgery procedure known as refractive lens exchange. In refractive lens exchange, the IOL is used solely in an attempt to reduce or eliminate the need for glasses or contact lenses. This article outlines some of the choices of IOLs that are available for use in cataract surgery and refractive lens exchange.
Fixed Focus Monofocal IOLs are used in the majority of cataract procedures. These lenses have the advantage of excellent quality distance vision under a variety of lighting conditions. Since these lenses have a fixed focal point which is generally set for distance vision, reading glasses are typically required for good near vision. For patients willing to use reading glasses for near tasks, these IOLs are an excellent choice. Several million lenses of this variety have been used for decades with an excellent safety record. Recent refinements in the optical quality of these lenses have allowed an even higher quality of vision than previously achievable.
Accommodating Monofocal IOLs are used in situations where both good distance and good near vision are desired without the use of spectacles. These IOLs have a single focal point, however, the focal point can shift position in space so that objects at distance are clear when the eye focuses on them, but when the eye looks at a near object the IOL will shift its focal point to bring the near object into focus. Accommodating Monofocal IOLs achieve this by physically moving inside the eye in response to the focusing action of the muscles of the eye. The only FDA approved IOL of this type is called the Crystalens™. Patients implanted with the Crystalens IOL generally enjoy near vision without glasses that is much better than those implanted with Fixed Focus Monofocal IOLs(2). In fact, results of the FDA trial for the Crystalens demonstrated that 98% of patients could see well enough to pass the driver's test and read a newspaper without glasses. Vision at the intermediate (computer screen) distance is superb with the Crystalens, making this an excellent IOL for those who spend a great deal of time on a computer.Cataract surgery today is typically performed using a microincisional procedure. To the patient, this means minimal discomfort during or after surgery, a more speedy recovery of vision, and reduced risk of induced astigmatism. This means less dependence on glasses afterwards.
Below, we've detailed the major steps of cataract surgery using a microincision procedure, phacoemulsification (ultrasonic cataract removal), and a foldable lens implant. This type of procedure is considered state-of-the-art for cataract surgery today. The procedure demonstrates basic principles only, however, and eye surgeons use many variations of the general theme, even from one case to another, depending on the type of cataract being removed. After discharge from the surgery center, patients will usually be asked to return for a follow-up visit later that day or the next day, however, this will be based on individual circumstances. Also depending on the type of incision and surgeon preference, some patients will be asked to wear a shield over the eye, particularly while sleeping. The eye should not be rubbed, or pressure placed directly on the eye through the eyelid, during the first few weeks following surgery. Eye drop medications will be required, usually consisting of antibiotic and anti-inflammatory medicines. These will often be tapered off during the first month after surgery.
The best vision may not be obtained until several weeks following surgery, but individual results vary considerably, depending on many variables. The great majority of patients may resume normal activities on the day of or day after surgery. Activities such as reading, watching television, and light work will not hurt the operated eye. Most surgeons arbitrarily recommend waiting 4 to 6 weeks before new glasses are obtained. This allows the eye to achieve considerable stability from a refractive standpoint and, therefore, the glasses prescription should be accurate and relatively stable.
Many patients are surprised at how clear their vision is after cataract surgery. Some patients may have better vision than they ever did before cataract surgery. Furthermore, depending on the degree of refractive error (need for glasses) prior to surgery, many patients will be much less dependent on glasses for far vision than they were before surgery. Patients will often notice that colors are brighter and more brilliant. The results are often dramatic.
An Orthoptist diagnoses and treats sight-related disorders such as amblyopia, strabismus and ocular motility. Other conditions managed by an orthoptist include cataract, retinal disease and glaucoma. Orthoptists are involved in diagnostic techniques such as tomometry and ultrasound of the eye. An orthoptist helps in managing neurological disorders or eye defects. Typically an orthoptist deals with children and their vision-related problems. This include teaching them how to use pediatric lenses and using eye patches.
Bibliography / Reference
Collection of Pages - Last revised Date: July 20, 2018