Definition
A cataract is a pathological clouding of the lens of the eye that results in decreased vision. Although it may occur earlier, cataracts are usually age-related. 42% of people between the age 52-64 have and 9 out of 10 at age over 75 have cataract. Complete blindness due to cataract is rare as most of the patients receive adequate medical help on time. Although many cataracts do not need to be removed, some may cause serious vision loss and decrease the quality of life.
The lens is the part of the eye situated behind the cornea and the iris. By changing its shape (process known as accommodation), the lens, along with the cornea, allows the light, coming from different distances, to be focused on the retina in order to receive a visual image. The lens is biconvex and is composed by lens capsule and nucleus lens epithelium and lens fibers. The lens does not possess blood vessels and nerves. That's because to accomplish its function, the lens needs to be completely transparent. When cataract appears, the clouding of the lens hardens the normal refraction and the light rays can not reach the retina.
A cataract is a pathological clouding of the lens of the eye that results in decreased vision. Although it may occur earlier, cataracts are usually age-related. 42% of people between the age 52-64 have and 9 out of 10 at age over 75 have cataract. Complete blindness due to cataract is rare as most of the patients receive adequate medical help on time. Although many cataracts do not need to be removed, some may cause serious vision loss and decrease the quality of life.
The lens is the part of the eye situated behind the cornea and the iris. By changing its shape (process known as accommodation), the lens, along with the cornea, allows the light, coming from different distances, to be focused on the retina in order to receive a visual image. The lens is biconvex and is composed by lens capsule and nucleus lens epithelium and lens fibers. The lens does not possess blood vessels and nerves. That's because to accomplish its function, the lens needs to be completely transparent. When cataract appears, the clouding of the lens hardens the normal refraction and the light rays can not reach the retina.
Causes
The lens is composed mainly by water and proteins. The proteins are situated in a specific way that does not interfere with the passage of the light. For reasons still unknown, with ageing, the arrangement of the proteins gets disturbed, the soluble proteins become insoluble which than precipitate. In the end the eye lens becomes thicker, less flexible and less transparent.
The lens is composed mainly by water and proteins. The proteins are situated in a specific way that does not interfere with the passage of the light. For reasons still unknown, with ageing, the arrangement of the proteins gets disturbed, the soluble proteins become insoluble which than precipitate. In the end the eye lens becomes thicker, less flexible and less transparent.
Risk factors
• Age
• Family history of cataract
• Diabetes
• Smoking
• Alcohol abuse
• UV-light exposure
• Long-term use of corticosteroids
• Changed calcium/ phosphorus ratio
• Eye trauma
• Vitrectomy
• Other eye diseases such as glaucoma, uveitis, retinal detachment
• Age
• Family history of cataract
• Diabetes
• Smoking
• Alcohol abuse
• UV-light exposure
• Long-term use of corticosteroids
• Changed calcium/ phosphorus ratio
• Eye trauma
• Vitrectomy
• Other eye diseases such as glaucoma, uveitis, retinal detachment
Symptoms
Cataract progresses slowly. The first signs are nonspecific. There is no pain or visible changes in the eye. That's why patients usually do not pay attention to them and seek medical help relatively late. Symptoms may include:
• Blurred vision
• Increased light sensitivity- one of the first signs of advancing cataract. Although the brightness of the light is normal, the patient perceives it as dazzling
• Light halos around objects
• Difficulty to read
• Double vision
• Disturbed night vision
• Changes in the color's perception
• Frequent changes of eyeglasses- as patients complain of decreased vision, first thing to do is to prescribe new eyeglasses. The problem is resolved for a short period of time, but then reappears.
Cataract progresses slowly. The first signs are nonspecific. There is no pain or visible changes in the eye. That's why patients usually do not pay attention to them and seek medical help relatively late. Symptoms may include:
• Blurred vision
• Increased light sensitivity- one of the first signs of advancing cataract. Although the brightness of the light is normal, the patient perceives it as dazzling
• Light halos around objects
• Difficulty to read
• Double vision
• Disturbed night vision
• Changes in the color's perception
• Frequent changes of eyeglasses- as patients complain of decreased vision, first thing to do is to prescribe new eyeglasses. The problem is resolved for a short period of time, but then reappears.
Tests
As all of the cataract's symptoms are nonspecific, they could be attributed to any other eye problem. That's why an ophthalmologist is the only one who could put the diagnosis after performing some tests. They include
• Visual acuity tests: not to forget that cataract may be the reason for frequent eyeglass change
• Ophthalmoscopy: after dilatation of the pupils, the doctor will be able to examine the transparency of the lens through a special microscope. Along with the lens, the retina is also being examined for eventual changes in its structure or blood supply
• Tonometry: measurement of the intraocular pressure is necessary as some types of glaucoma may lead to cataract
As all of the cataract's symptoms are nonspecific, they could be attributed to any other eye problem. That's why an ophthalmologist is the only one who could put the diagnosis after performing some tests. They include
• Visual acuity tests: not to forget that cataract may be the reason for frequent eyeglass change
• Ophthalmoscopy: after dilatation of the pupils, the doctor will be able to examine the transparency of the lens through a special microscope. Along with the lens, the retina is also being examined for eventual changes in its structure or blood supply
• Tonometry: measurement of the intraocular pressure is necessary as some types of glaucoma may lead to cataract
Treatment
Surgery is the only option available for definitive cataract treatment. There are no drugs for this condition. However, not all patients with cataract need a surgery. It is only necessary when the vision loss troubles the daily activities of the patient. As cataract develops very slowly, surgery can be delayed with years if the individual considers his vision good enough to live with it. While this happens, eyeglasses or lenses could be prescribed. Two main surgery approaches exist:
• Extracapsular extraction: The anterior part of the lens capsule is cut and then the nucleus is extracted. Since the capsule is preserved, different kind of artificial lenses could be implanted, usually in the posterior chamber of eyeball. The disadvantage of this type of surgery is that the remaining capsule could eventually form a cicatrix and therefore secondary cataract that would need another surgery to be removed.
• Intracapsular extraction: the whole lens is being removed, including its capsule. This method hides a risk of prolapse of the vitreous body (a structure of the eye, situated between the lens and the retina, composed by jelly-like substance that determines the form of the eye). If this is the case, new surgical intervention would be necessary. During the intracapsular extraction, a new lens could be implanted into the anterior chamber of the eyeball.
Surgery is the only option available for definitive cataract treatment. There are no drugs for this condition. However, not all patients with cataract need a surgery. It is only necessary when the vision loss troubles the daily activities of the patient. As cataract develops very slowly, surgery can be delayed with years if the individual considers his vision good enough to live with it. While this happens, eyeglasses or lenses could be prescribed. Two main surgery approaches exist:
• Extracapsular extraction: The anterior part of the lens capsule is cut and then the nucleus is extracted. Since the capsule is preserved, different kind of artificial lenses could be implanted, usually in the posterior chamber of eyeball. The disadvantage of this type of surgery is that the remaining capsule could eventually form a cicatrix and therefore secondary cataract that would need another surgery to be removed.
• Intracapsular extraction: the whole lens is being removed, including its capsule. This method hides a risk of prolapse of the vitreous body (a structure of the eye, situated between the lens and the retina, composed by jelly-like substance that determines the form of the eye). If this is the case, new surgical intervention would be necessary. During the intracapsular extraction, a new lens could be implanted into the anterior chamber of the eyeball.
The improvement of the
vision does not come right after the surgery as the operated eye needs time to
adapt to the vision of the healthy one. It is advised not to overcharge the
eyes while this happens.
Conclusion
Different marketing campaigns tend to convince patients that they need cataract surgery, while this is not always the case. Surgery could be postponed if you feel that you can continue your normal life even with blurred vision. Surgery is to be considered when the vision loss becomes so serious that troubles your reading, driving or other activities.
Different marketing campaigns tend to convince patients that they need cataract surgery, while this is not always the case. Surgery could be postponed if you feel that you can continue your normal life even with blurred vision. Surgery is to be considered when the vision loss becomes so serious that troubles your reading, driving or other activities.
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