CATARACTMembers: Bryan Lim Lo Suy, Julia Acapulco, Ben Francisco, ArianePineda, Lizter Chan, Alexa Bacong
What is Cataract?• Cataracts are changes in clarity of the natural lens inside the eye that gradually degrade visual quality.• Clouding that develops in the crystalline lens of the eye or in its envelope (lens capsule), varying in degree from slight to complete opacity and obstructing the passage of light
Cause• The lens is made mostly of water and protein. Specific proteins within the lens are responsible for maintaining its clarity. But as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract, and over time, it may grow larger and cloud more of the lens, making it harder to see. The following causes are...
• Ultraviolet radiation from sunlight and other sources -Sunlight consists of ultraviolet (referred to as UVA or UVB) radiation, which penetrates the layers of the skin. Both UVA and UVB have destructive properties that can promote cataracts. The eyes are protected from the sun by eyelids and the structure of the face (overhanging brows, prominent cheekbones, and the nose). Long-term exposure to sunlight, however, can overcome these defenses.• Diabetes -High blood sugar in diabetes causes the lens of the eye to swell, which changes your ability to see. To correct this kind of eye problem, you need to get your blood sugar back into the target range (90- 130 milligrams per deciliter or mg/dL before meals, and less than 180 mg/dL one to two hours after a meal). It may take as long as three months after your blood sugar is well controlled for your vision to fully get back to normal.• Hypertension
• Obesity• Smoking -Cigarette smoking is a definite risk factor for cataracts and it is dose related - the more you smoke and the longer the duration of smoking, the greater the cataract risk.• Prolonged use of corticosteroid medications -Because oral corticosteroids affect your entire body instead of just a particular area, this form is the most likely to cause significant side effects. Side effects depend on the dose of medication you receive. - Corticosteroids mimic the effects of hormones your body produces naturally in your adrenal glands, which sit atop your kidneys. When prescribed in doses that exceed your bodys usual levels, corticosteroids suppress inflammation, which can reduce the signs and symptoms of inflammatory conditions, such as arthritis and asthma.• Statin medicines used to reduce cholesterol -"Statins" is a class of drugs that lowers the level of cholesterol in the blood by reducing the production of cholesterol by the liver. (The other source of cholesterol in the blood is dietary cholesterol.) Statins block the enzyme in the liver that is responsible for making cholesterol.• Previous eye injury ,Inflammation or Previous eye surgery• Hormone replacement therapy• Significant alcohol consumption• High myopia• Family history
Types of Cataract• A subcapsular cataract occurs at the back of the lens. People with diabetes or those taking high doses of steroid medications have a greater risk of developing a subcapsular cataract.• A nuclear cataract forms deep in the central zone (nucleus) of the lens. Nuclear cataracts usually are associated with aging.• A cortical cataract is characterized by white, wedge- like opacities that start in the periphery of the lens and work their way to the center in a spoke-like fashion. This type of cataract occurs in the lens cortex, which is the part of the lens that surrounds the central nucleus.
Who usually gets affected by Cataract?• While cataracts are often associated with aging, there is no hard and fast rule as to who gets them. They can form in adults as early as age 40. They can also affect babies and small children. In some cases, they are hereditary.
How to prevent getting Cataract?• The standard cataract surgical procedure is typically performed in either a hospital or in an ambulatory surgery center. The most common form of cataract surgery today is a process called phacoemulsification. With the use of an operating microscope, your surgeon will make a very small incision in the surface of the eye in or near the cornea. A thin ultrasound probe is inserted into the eye that uses ultrasonic vibrations to dissolve (phacoemulsify) the clouded lens. These tiny fragmented pieces are then suctioned out through the same ultrasound probe. Once the cataract is removed, an artificial lens is placed into the same thin capsular bag that the cataract occupied. This intraocular lens is essential to help your eye focus after surgery.
There are three basic techniques for cataract surgery:• Phacoemulsification: This is the most common form of cataract removal as explained above. In this most modern method, cataract surgery can usually be performed in less than 30 minutes and usually requires only minimal sedation and numbing drops, no stitches to close the wound, and no eye patch after surgery.• Extracapsular cataract surgery: This procedure is used mainly for very advanced cataracts where the lens is too dense to dissolve into fragments (phacoemulsify) or in facilities that do not have phacoemulsification technology. This technique requires a larger incision so that the cataract can be removed in one piece without being fragmented inside the eye. An artificial lens is placed in the same capsular bag as with the phacoemulsification technique. This surgical technique requires a various number of sutures to close the larger wound, and visual recovery is often slower. Extracapsular cataract extraction usually requires an injection of numbing medication around the eye and an eye patch after surgery.• Intracapsular cataract surgery: This surgical technique requires an even larger wound than extracapsular surgery, and the surgeon removes the entire lens and the surrounding capsule together. This technique requires the intraocular lens to be placed in a different location, in front of the iris. This method is rarely used today but can be still be useful in cases of significant trauma.
Complications of Cataract Surgery• While cataract surgery is one of the safest procedures available with a high rate of success, rare complications can arise. Your ophthalmologist will discuss the specific potential complications of the procedure that are unique to your eye prior to having you sign a consent form. The most common difficulties arising after surgery are persistent inflammation, changes in eye pressure, infection, or swelling of the retina at the back of the eye, and retinal detachment. If the delicate bag the lens sits in is injured, then the artificial lens may need to be placed in a different location. In very rare cases, the intraocular lens moves or does not function properly and may need to be repositioned, exchanged, or removed. All of these complications are extremely rare but can lead to significant visual loss if left untreated; thus, close follow-up is required after surgery.• In some cases, within months to years after surgery the thin lens capsule may become cloudy, and you may have the sensation that the cataract is returning because your vision is becoming blurry again. This process is termed posterior capsule opacification, or a "secondary cataract." To restore vision, a laser is used in the office to painlessly create a hole in the cloudy bag. This procedure takes only a few minutes in the office, and vision usually improves rapidly.
How to avoid/ Prevention of Cataract• At present, there is no real effective way to prevent the formation of cataracts, so secondary prevention involves controlling other eye diseases that can cause cataracts and minimizing exposure to factors that promote cataracts...• Wearing sunglasses outside during the day might reduce your chances of developing cataracts or having problems with the retina. Some sunglasses can filter out UV light, reducing exposure to harmful UV radiation and might slow the progression of cataracts.
• Some people take vitamins, minerals, and herbal extracts to decrease cataract formation. No scientific data prove that these remedies are effective. No topical or oral medications or supplements are proven to decrease the chance of developing cataracts.• A healthy lifestyle might help, just as a healthy lifestyle helps prevent other diseases in the body. Eat a proper diet, get regular exercise and rest, and do not smoke.• If you have diabetes, tight blood-sugar control can delay the otherwise accelerated development of cataracts.