Total or partial loss of lens transparency (opacification). Causes of cataract may be aging, traumas, environmental factors (radiation, drugs, etc), some ocular abnormalities (congenital cataract).
A cataract is a cloudiness or opacity in the normally transparent crystalline lens of the eye. This cloudiness can cause a decrease in vision and may lead to eventual blindness.
Causes of cataract may be aging, traumas, environmental factors (radiation, drugs, etc), some ocular abnormalities (congenital cataract).
Gradual and progressive reduction in visual acuity, perception of split images and halos around light sources, change in vision capacity in relation to the variation of ambient light intensity.
There are several common symptoms of cataracts:
• gradual, painless onset of blurry, filmy, or fuzzy vision
• poor central vision
• frequent changes in eyeglass prescription
• changes in color vision
• increased glare from lights, especially oncoming headlights when driving at night
• "second sight" improvement in near vision (no longer needing reading glasses), but a decrease in distance vision
• poor vision in sunlight
• presence of a milky whiteness in the pupil as the cataract progresses.
Surgery: removing the clouded lens, which is replaced with an intraocular lens or "artificial crystalline lens".
Cataract surgery is preceded and followed by the administration of prophylactic drug treatments in order to prevent and avoid inflammatory and infectious complications, of which the most serious is postoperative endophthalmitis.
Cataract is the total or partial loss of natural lens, located behind the iris, transparency (opacification), which has the task of converging light rays on the retina.
The name derives from the Greek katarraktês, which means "something that falls from top to bottom", to express the idea of a screen that prevents the eye from seeing when the lens becomes opaque.
The chances of developing cataracts increase with age, especially after 60 years, due to the physiological ageing of the lens. This is not, however, a condition that only affects the elderly because there are congenital cataracts, present at birth, and cataracts of different origin such as those due to traumas, those caused by prolonged exposure to ionizing radiation, and those induced by medications used either locally or systemically (e.g. cataracts from cortisone).
It is also important to remember that excessive and prolonged exposure to sunlight is another risk factor for the development of cataracts. There are also forms of cataract associated with other eye diseases such as glaucoma, uveitis, or systemic diseases, such as diabetes.
Very often cataract is a bilateral disease, which occurs first in one eye and subsequently develops in the other.
Sometimes a cataract can take only a few months to develop, but most of the time the process takes years; sometimes causing immediate problems, other times it causes no discomfort for months.
The most common symptom is progressive and gradual loss of vision: the patient realises that his/her vision goes dark and clouds; encounters difficulty in reading, watching television, in distinguishing objects placed at a modest distance, in driving especially at night.
It is not rare to perceive split images and halos around light sources (lamps, lights, etc).
Another symptom is the change of vision capacity in relation to the variation of ambient light intensity.
For the diagnosis of cataracts and to establish a "threshold" at which it is appropriate to resort to surgery with good prospects of postoperative visual improvement, a thorough eye examination is necessary, in order to provide an accurate assessment of the health of the eye and the impaired visual function.
Cataracts cause visual problems that are reversible through a surgical procedure to remove the clouded lens.
The phacoemulsification technique is normally used. It is carried out using an ultrasound probe, which fragments and sucks the clouded lens.
The femtosecond laser or femtolaser, which can provide high safety standards and operating precision, has recently been introduced in cataract surgery.
Once the cataract has been removed, in order to restore a satisfactory vision, an intraocular lens (IOL) or "artificial crystalline lens" is implanted.
This lens is made of biocompatible materials and ,once positioned, is fixed inside the eye and does not need to be cleaned or replaced. Modern IOL may restore a good quality of vision, as long as the other structures of the eye, particularly the retina, are healthy.
In the most modern implantation techniques the IOL can be inserted into the eye through very small incisions (mini-and micro-incision), which do not require any stitches.
Furthermore, the IOL choice takes into account the patient’s refractive errors (myopia, hypermetropia, and presbyopia), in order to compensate them, in whole or in part, and reduce or eliminate the need to wear glasses (refractive cataract).
Cataract surgery is preceded and followed by the administration of prophylactic drug treatments, which are defined and approved by the guidelines of the major scientific organisations, in order to prevent and avoid inflammatory and infectious complications, of which the most serious is postoperative endophthalmitis.
