Correct Cloudiness in the Eyes' Lenses (Cataracts)
A cataract is the change in clarity, or "clouding," of the lens within the eye. The lens, located just behind the iris (or colored part of the eye) works like the lens in a camera – focusing light images onto the retina, which sends images to the brain. When the lens loses its transparency, images aren’t as clear. About 50% of Americans between the ages of 65 and 74 and 70% of those over 75 have some stage of cataract development. Eye injury, certain diseases, or even some medications can cause the clouding. However, in over 90% of cases, clouding is caused by the aging process.
As the lens ages, although it may still be clear, it becomes harder and less flexible, and less able to change shape for near vision (accommodation). Reading glasses become useful to manage the condition. This process becomes apparent at about age 40 and continues until accommodation is lost, typically by age 65. Loss of accommodation of the lens is a normal aging process, known as presbyopia. Reading glasses become stronger over time to compensate for the loss of ability to focus up close.
The initial symptoms of cataract make it appear as if one is looking through a dirty window. A cataract may be the reason sharp images become blurred, bright colors become dull, or seeing at night is more difficult. It may also be why the reading glasses or bifocals that used to work well don’t help as much.
At present, despite a great deal of research and numerous over-the-counter remedies, there is no proven nonsurgical treatment to cure or retard the development of cataracts. Those who focus on the relationship between dietary patterns and various diseases see evidence that people whose diets are rich in antioxidants (vitamin A and carotene) may be less likely to develop cataracts. It is unlikely that one can benefit from taking multivitamin supplements in the face of a diet lacking in fruits and vegetables. On the other hand, people who eat spinach and broccoli for carotenes are sure to benefit from the other nutrients that these vegetables contain. Prolonged exposure to ultraviolet (UV) light may play a role in the formation of cataracts. UV protection in all glasses, clear or tinted, is a good idea. Large population studies have also shown that cigarette smokers face up to twice the risk as nonsmokers in developing cataracts…another reason not to smoke. The best way to treat a significant cataract is to remove the old, clouded lens and restore the vision with a replacement. When is a cataract “ripe”? The time to have your cataracts removed is when the quality of your vision begins to put limits on your activities and enjoyment of life.
Since couching was developed in the Middle Ages, no medical procedure has seen more technological advancement than lens removal. Cataract removal is one of the safest and most effective surgical procedures. More than 3 million cataract surgeries are performed each year in the United States. Cataract surgery is the most frequent surgical procedure performed in patients 65 or older. During surgery, the natural lens (which has become clouded) is removed and replaced with and artificial lens implant called an intraocular lens (IOL). IOLs are made of a flexible, foldable plastic which lasts virtually forever. Once a cataract has been removed it cannot return.
Cataract surgery is an outpatient procedure. Today, cataract surgery is done with microsurgical instruments under the high magnification of an operating microscope. Under topical anesthesia (no needles) with intravenous sedation, an incision of 3 mm or less allows ultrasonic phacoemulsification, or liquefaction, of the lens. The ultrasonic tip allows vacuum tubing to remove the cloudy lens material leaving a clear lens capsule. A foldable IOL, specifically selected for the proper correction of near-sightedness (myopia), far-sightedness (hyperopia), irregular contour (astigmatism), and even accommodation (presbyopia), is inserted through the same incision, and positioned in this exact location, permanently replacing the natural lens. The tiny incision is designed to seal without stitches. The entire operation typically takes about 15 minutes.
Patients typically leave the surgical facility with functional vision, wearing a clear plastic shield over the operated eye. There is usually minimal discomfort. While there are short term limitations on exercise and cosmetics, most patients are back to their normal activities the next day. Eye drops are provided to prevent infection and speed healing. Vision improves soon after surgery and sight should continue to improve for several weeks. Depending on the IOL selected, patients often need to wear glasses for tasks such as reading or working at a computer.
New Lens Technology
When the natural lens is removed during cataract surgery, an IOL (intraocular lens) is inserted to take its place. Before IOLs were developed, one had to wear thick glasses or special contact lenses to be able to see after surgery. Now there are several different types of IOLs available for patients undergoing cataract surgery. Before surgery is performed, the eyes are measured to determine corneal astigmatism and the correct power of IOL for you.
For several decades, monofocal lens implants have been extremely successful. The power of IOL is selected to allow the eye to see best at either near, far or intermediate distance without glasses. Most patients select an IOL that provides good distance vision without eyeglasses and they wear reading glasses for near.
The outermost portion of the eye is the cornea. The cornea is a clear dome that provides most of the focusing power of the eye. Since it is a biological tissue, corneas are rarely perfectly round, or spherical. Sometimes the surface of the cornea is more like a football than a basketball. The degree which a cornea is not round is called astigmatism. While the power of a traditional monofocal IOL is calculated to correct near-sightedness (myopia) or far-sightedness (hyperopia), a person who has both cataract and corneal astigmatism will not regain high-quality distance vision after surgery to remove the cataract unless the astigmatism is also corrected.
Corneal astigmatism may be corrected at the time of surgery in two ways. Limbal relaxing incisions may be used to change the surface contour. Anatomically, the limbus is the zone where the cornea meets the white of the eye. Calculations are done to determine the length of one or two fine peripheral corneal incisions. The astigmatic correction is made at the start of cataract surgery which then proceeds in the usual fashion.
A Toric IOL may be implanted during cataract surgery to replace the clouded lens. This is a Monofocal IOL that makes it possible to reduce or eliminate both refractive error (myopia or hyperopia) and corneal astigmatism, to significantly improve uncorrected vision.
With a monofocal lens set for distance, reading glasses are needed for close-up vision. This same condition – the need to wear eyeglasses to change focus – affects everyone by middle age due a natural aging condition known as presbyopia. Presbyopia develops as the natural lens loses flexibility, making zooming in up close more difficult. After initially zooming out with extended arms and better lighting, reading glasses become necessary.
Many patients expect to be free of glasses following cataract removal. To become less dependent on eyeglasses for both near and far after cataract surgery, multifocal and accommodative IOLs have been designed.
Multifocal IOLs use specially designed focal zones on the surface of the lens. Light rays are focused through the different zones to provide sharply focused images at both near and far. In the clinical study, 80% of patients receiving the AcrySof® ReSTOR® IOL reported that they never wear glasses for any activities. With the AcrySof® ReSTOR® IOL they can read a book, work on the computer and drive a car – day or night – and play golf or tennis with an increased freedom from glasses. In fact, patients were so pleased with their vision, nearly 94% of patients said they would have the AcrySof® ReSTOR® IOL implanted again, if given the choice.
An accommodative IOL has design features that allow the natural focusing mechanism of the eye to move or flex the lens implant.The movement results in some adjustment to focus, which in turn improves the ability to see clearly at different distances without eyeglasses when compared to a traditional monofocal IOL.Crystalens® is the first and only FDA-approved accommodating lens. This vision enhancement system requires absolute accuracy in pre-operative measurements of IOL power, corneal curvature and refraction to optimize the capabilities of the accommodating Crystalens®. Achieving these standards requires the doctor and his clinical staff to focus on precision, predictability and personalized patient care.
All of these IOL systems work well. The success rate of cataract surgery is one of the highest among all surgeries. As with any surgery, there are potential risks. You should fully understand the risks, benefits and alternative before you make a decision regarding cataract surgery. You must consider how important it is for you to reduce your dependence on wearing eyeglasses after cataract surgery. You’ll also need to think about cost. Cataract surgery with a traditional Monofocal IOL is covered by Medicare, MediCal and nearly all health insurance plans. However, while the cataract surgery itself remains a covered service, special IOLs that provide the convenience of seeing better without eyeglasses are not considered medically necessary, therefore, their additional cost is not covered by health insurance. Patients who want the benefits provided by these enhanced IOLs must pay the additional cost of these lenses out-of-pocket.
Glaucoma is a condition in which there is damage to the optic nerve. This may result in gradual vision loss and eventual blindness. There is no single test for glaucoma. During a thorough eye examination, your Ophthalmologist will evaluate risk factors that cause glaucoma. Risk factors include elevated intraocular pressure, increasing age, thinner cornea, abnormal visual fields and abnormal optic nerve appearance. Elevated intraocular pressure alone does not cause glaucoma. In fact, up to 40% of patients with glaucoma have what would be considered normal intraocular pressure. On the other hand, the only risk factor that can be treated is intraocular pressure.
A clear fluid, called aqueous humor, fills the portion of the eye anterior to the lens. Functioning like clear blood, aqueous humor provides nourishment to the tissues. Like air in a balloon, the aqueous also provides pressure to help maintain the shape of the eye and the health of the optic nerve. Aqueous humor is secreted adjacent to the lens from the ciliary processes. It circulates through the pupil, bathing the back of the cornea. The liquid then drains from the eye through a meshwork where the cornea meets the iris. Since the cornea is a dome and the iris is flat, an angle is created where they meet. There is a feedback mechanism that controls secretion and drainage to maintain normal eye pressure.
Open Angle Glaucoma
In Open Angle Glaucoma, the angle appears normal but there is either too much fluid produced or a decrease in fluid drainage. With this imbalance in flow, there is a slow, gradual increase in intraocular pressure (IOP). The elevated eye pressure usually occurs without symptoms. Over time, without therapy, this causes irreversible damage to susceptible optic nerve fibers. Initially, only peripheral vision is affected.
Treatment begins with suspicion of the condition. Regular eye examinations should be done to screen for relevant risk factors. Topical therapy with eye drops can lower the pressure sufficiently to prevent further damage to the optic nerve. In most cases, once a day therapy is sufficient. Selective Laser Trabeculoplasty (SLT) is an outpatient procedure that takes 10-15 minutes. It causes a biological response that increases aqueous humor drainage, promptly reducing intraocular pressure. More advanced, resistant forms of open angle glaucoma may require surgery.
Narrow Angle Glaucoma
In Narrow Angle Glaucoma, the anatomy of the angle is compromised whereby the cornea is much closer to the iris. Sudden closure of the angle may occur with dilation of the pupil, causing drainage to suddenly stop. The eye pressure rises precipitously, promptly leading to closure of the central retinal artery and blindness.
Preventative (or rarely emergency) therapy with Laser Peripheral Iridotomy (LPI) is the treatment of choice. A tiny hole is created in the peripheral iris, preventing angle closure. Eye drops cannot change the drain anatomy effectively. LPI is a brief office procedure that should prevent narrow angle glaucoma forever. Only a thorough eye examination by your Ophthalmologist can determine if you have narrow, occludable angles.
Lasers in Ophthalmology
Ophthalmology was one of the first medical fields to embrace laser technology, and after more than 40 years, Ophthalmologists remain among the leaders in laser applications. Laser is an acronym for Light Amplification by the Stimulated Emission of Radiation. A laser is a concentrated beam of light energy, created when an electric current passes through a special material. Lasers may be either hot (like soldering) or cold (like a knife). The combination of energy and type of material determines the properties of the particular laser. Lasers are used in virtually every aspect of Ophthalmology from diagnosis to treatment. Were it not for lasers, many of the disease stricken could go blind.
The retina is the inner layer of the eye similar to the film in a camera. If the retina tears, it may separate from the back wall of the eye. This is called a detached retina. Where the retina is detached, there is no vision. Symptoms of retinal tears include sudden flashes of light and floaters. Most retinal tears may be sealed with laser treatment preventing retinal detachment. If retinal detachment has already occurred, laser therapy may be used as part of a surgical repair of the detachment.
Diabetes may cause blood vessels in the eye to grow abnormally. The vessels may leak fluid or bleed. National trials have been completed and guidelines for appropriate candidates for laser treatment have been developed. Laser treatments seal leaking blood vessels and may slow or stop the growth of abnormal vessels. These treatments help prevent vision loss and decrease the chance of bleeding within the eye. The development of diabetic retinopathy is related to duration of disease and stability of control. Regular eye examinations have been shown to markedly reduce the incidence of vision loss related to diabetes by finding early changes that are amenable to treatment.
The macula is the small, central area of the retina that allows us to see fine details clearly. The macula has the highest blood flow in all of the human body. Ninety percent of all people with macular degeneration have the dry form. Studies indicate that dry macular degeneration is caused by aging (thus the name age-related macular degeneration: ARMD). Smoking is the other major risk factor. Over time, there is a gradual reduction in vision that may interfere with reading, writing or, even, driving a car. While there is no proven treatment for dry ARMD, it has been shown that nutritional supplements, containing lutein and zinc, may slow the progression of the disease.
Although only ten percent of people with ARMD have the “wet” kind, it is a much greater threat to vision. Rapidly growing, abnormal blood vessels begin to hemorrhage, leaking blood and plasma that may destroy the macula. Combination therapy with laser treatment and injections into the eye has revolutionized therapy. These therapies may also be applied to retinal vascular occlusions, macular edema, and certain ocular tumors.
After Cataract Membrane
Cataract describes a clouding of the natural lens. The lens has a cellophane-like covering called the capsule. In the most advanced cataract surgeries, the front of the capsule is opened and an ultrasonic probe is used to emulsify the lens contents. Once the cloudy lens material is removed, an intraocular lens implant is inserted into the clear capsular bag to provide good vision.
Weeks or months later, the lens capsule may lose its transparency or wrinkle, causing a reduction in vision. A noninvasive laser procedure is used to create a small, central opening in the posterior capsule. This clears the vision while maintaining support for the intraocular lens. The brief procedure is done in the office after the application of topical anesthetic drops.
Glaucoma is a disease of the optic nerve related to elevated intraocular pressure. Glaucoma is the second most common cause of blindness in the United States. Loss of vision from glaucoma may often be prevented if the Ophthalmologist discovers the disease before significant damage has occurred. While eye drops are the usual way to treat glaucoma, if the eye pressure is not adequately controlled, laser surgery to lower the eye pressure is often successful. In open angle glaucoma, lasers may be used for Selective Laser Trabeculoplasty (SLT) or Argon Laser Trabeculoplasty (ALT). In narrow angle glaucoma, lasers are used for Laser Peripheral Iridotomy (LPI).
Excimer lasers are used in Photorefractive Keratectomy (PRK), Laser in Situ Keratomileusis (LASIK), and Phototherapeutic Keratectomy (PTK) to sculpt the cornea and thereby reduce or eliminate the need for glasses or contact lenses. State of the art technology allows us to do “All Laser LASIK”. After measuring the eye for “wavefront” correction of surface irregularities, Intralase is used to create the flap. Then the flap is lifted to do the brief, corneal ablation to correct myopia (near-sightedness), hyperopia (far-sightedness) and astigmatism.
In some people, tears well up in the eye because too many tears are produced or because the tears are not draining properly. Excess tears give the eye a moist appearance, and can collect along the border of the lower lid and overflow onto the cheek.
Small glands, located in the surface tissue on the white of the eye and lining the eyelids, constantly produce small quantities of tears to keep the eye healthy and lubricated. The lacrimal gland, a larger gland located in the upper eyelid, responds to emotion or eye irritation by producing larger quantities of tears.
After bathing the eye’s surface, tears enter a small opening in each lid (the punctum), drain through a small canal (cannaliculus) into the lacrimal sac and down the nasolacrimal duct into the nose. This explains why we have a runny nose when we cry, since the excess tears reach the nose through the normal tear drainage system.
Improper tear drainage and overflow tearing can be caused by malpostioned eyelid or punctum; faulty blinking; orbital injury; birth defects; infections; and complications of burns or radiation therapy. Excess tear production can be caused by: superficial foreign bodies; wind, smoke and fumes; infections, allergic reactions; glaucoma; eyestrain; emotion; and dry eyes.
Surprisingly, people with dry eyes often complain of tearing. Even though the underlying problem is too few lubricating tears to keep the eye moist, the large lacrimal gland often reacts by producing an excessive amount of tears. Instead of draining normally, the excess tears will run down the cheeks.
A thorough examination by an ophthalmologist is necessary to determine which of these problems is causing excessive tearing. An attempt may be made to irrigate fluid through the tear drainage system and into the nose. Other tests such as measuring tear production or recovering tears from the nose may also be performed.
Treatment depends on the exact cause. If excess tears are caused by an in-turned eyelash, the offending eyelash is removed. Abnormalities of the eyelid or eyelid position may require surgery. If the tear drainage system is blocked, surgery to open or bypass the blockage may be necessary. Occasionally, the exact cause cannot be determined. In such cases, the patient may have to learn to live with the problem.
Styes and Chalazions
The upper and lower eyelids contain oil glands called meibomian glands. The glands are oriented in a vertical fashion, like a piano keyboard. Meibomian glands secrete oils at the lid margin to smooth the optical surface, to retard the evaporation of tears, and to seal the lids while asleep.
For undetermined reasons, sometimes related to a chronic inflammatory lid disease called blepharitis, a gland may become clogged and inflamed. In its acute stage, the gland may swell to many times its original size, producing pain and redness. This is called a stye or hordeolum. Most times, such a lesion spontaneously resolves without therapy. Other times it remains tender and unsightly. The pain and redness of a stye may resolve, leaving the enlarged gland as a firm cyst, or chalazion.
The management of styes and chalazions is focused on allowing the gland to drain, returning to its normal anatomy and function. This is accomplished through the systematic use of hot compresses. Hot compresses induce expansion of the lesion until it drains. To properly do hot compresses, water from a sink should be turned on to hot only. A clean washcloth should be soaked and, when the temperature is tolerable, applied to the closed affected eye for thirty seconds. The cloth should be remoistened and reapplied for a total of 3 minutes, three times a day. This remedy may induce mild redness around the eye, often focused on the lesion. A tube of antibiotic-steroid ointment will be prescribed to treat this irritation. Surgical drainage of these lesions is rarely necessary. Surgery may be considered once a stye has evolved into a chronic chalazion, unresponsive to therapy. Incision damages the gland and increases the likelihood of recurrence. Therefore, compresses remain the treatment of choice, however, perseverance is necessary as it may take days to weeks to achieve resolution.
A pterygium is fleshy tissue that grows over the cornea (the clear front window of the eye), like a callus. It may remain small or may grow large enough to interfere with vision. A pterygium most commonly occurs at the inner corner of the eye, but can appear on the outer corner as well.
The exact cause is not well understood. Pterygium occurs more often in people who spend a great deal of time outdoors, especially in sunny climates. Long-term exposure to sunlight, especially ultraviolet (UV) rays, and chronic eye irritation from dry, dusty conditions seem to play an important causal role. A dry eye may contribute to pterygium.
When a pterygium becomes red and irritated, eyedrops or ointments may be used to help reduce the inflammation. If the pterygium is large enough to threaten sight, grows excessively, or is unsightly, it may be removed surgically. Despite proper surgical removal, the pterygium may return, particularly in young people. Surface radiation or medications are sometimes used to help prevent recurrences.
Protecting the eyes from excessive ultraviolet light with proper sunglasses and avoiding dry, dusty conditions and use of artificial tears may also help.
A pinguicula is a yellowish patch or bump on the white of the eye, most often on the side closest to the nose. It is not a tumor, but an alteration of normal tissue resulting in a deposit of protein and fat. Unlike a pterygium, a pinguicula does not actually grow onto the cornea. A pinguicula may also be a response to chronic eye irritation or sunlight.
No treatment is necessary unless it becomes inflamed. A pinguicula does not grow onto the cornea or threaten sight. If particularly annoying, a pinguicula may on rare occasions be surgically removed, but the postoperative scar may be as cosmetically objectionable as the pinguicula.