The Normal eye and Cataract Formation:
When Dr Peace explains the functions of the human eye, a camera is used for comparison because the eye and the camera operate in a very similar manner. In a camera, light travels through the clear lens and is then focused and recorded on film. In the human eye light travels through the cornea to the clear lens, which is located behind the dark central pupil of the eye. The lens focuses light rays on the retina, which can be compared to the film of the camera. The retina then transmits the images through the optic nerve to the brain, where they are interpreted as identifiable objects. The iris, or colored part of the eye, opens and closes to allow more or less light to enter the eye, much as the diaphragm in a camera opens and closes. Regular periodic check-ups at the Diabetic Eye Medical Clinic will help determine if your eyes are functioning properly.
If the lens in the eye becomes cloudy, it is known as a cataract. This can be the result of aging, accident or certain diseases. If you have a cataract, your vision will become blurred. You may notice that color becomes less distinct or vibrant, which may take place over a period of months or even years. Cataracts can develop in one or both eyes. It is not true that a cataract is a film or later on the outside of the eye. It is located inside the eye within the lens. There are several types of cataracts. If you are interested in knowing what type of cataract you have, please contact the Diabetic Eye Medical Center.
The right time to remove the cataract depends on your daily visual needs. When your visual impairment interferes with your job or daily life, it is time to consider having the cataract removed. There are several surgical techniques to choose from when your cataract is removed. The method chosen depends on the type of cataract you have along with several other factors. One method of cataract extraction is called the extracapsular method, which offers certain advantages when compared to other methods. The lens of the eye is surrounded by a clear capsule much as a grape is surrounded by a peel. Using the extracapsular method, a small opening is made in front of the eye and the cataract is removed from the capsule, or peel the grape. A tiny instrument can be inserted that breaks the cataract up into tiny pieces through the use of high frequency sound waves that emulsify and remove the cataract. This is called the phacoemulsification method. Another method of extracapsular extraction is to make a small opening in the front part of the capsule. The central part, or nucleus, is removed in one piece. The outer shell of the cataract, which is softer, is then removed by delicate suction. The extracapsular method of cataract extraction is the most technologically advanced method available today. This method preserves the capsule (a protective membrane) and thereby reduces certain ocular complications such as retinal detachment and edema of the macula. Although the laser beam has many applications in ophthalmology, it cannot be used to remove a cataract.
Restoring Vision After Cataract Surgery
A cataract can be thought of as a defective focusing device. After your cataract has been removed, light can once again enter the eye. However, because the focusing device has been removed, the eye cannot focus light rays onto the retina, which results in blurred vision. This condition is called aphakia (without natural lens). It is now necessary to replace the cataractous lens with some other focusing device. There are three methods available to restore vision after the cataract has been removed. Contact lenses or thick eye- glasses can be used or this purpose. The thick cataract glasses have a tendency to blur the side vision and magnify objects up to 30% more than normal. Contact lenses do not offer some of the problems that thick cataract glasses do; however, patients with unsteady hands may have a problem inserting or removing them.
One of the most recent developments in cataract surgery is to replace the cataractous lens with an intraocular lens implant. These lenses are inserted into the eye, where they remain permanently.It is never necessary for the patient to touch or remove them.Intraocular lenses, about the same size as your fingernail do not result in distortions, as do thick glasses. They look like the normal lens to other people. Even if a lens has been implanted in your eye, it may be necessary to wear regular glasses after surgery. The strength of the implant will be determined by Dr Peace based on tests before the operation.
Before your lens became a cataract, light rays were clearly focused on the retina by your clear lens. As the cataract worsened, it blocked the light rays which resulted in blurred and cloudy vision. The cataract operation with insertion of the intraocular lens implant again follows light to be focused clearly on the retina. Following your recover time and a change in your glasses, this results in improved vision for you.
Use of the Yag Laser Beam:
After successful cataract surgery has been performed, occasionally, the capsule to which the implant has become attached may become milky or opaque. Opacification of this protective membrane has been referred as a secondary cataract or secondary membrane. If this does occur, it is a relatively simple matter to make an opening in this membrane with a laser beam. The laser beam is not used to remove your cataract.