What is cataract ?
Cataract is the clouding of lens, placed lens inside the eye behind the pupil, where passes the vision. In the normal state, when it has no cataract, the lens is transparent and allows you to focus the image on the retina, Visual area lining the posterior wall of the eye that receives Visual information and transmits it to the brain. When the lens is opaque, it’s cataract, light can no longer pass through and vision is blurred. Cataract surgery is the most practiced surgery in the world all surgeries combined. In France, 600000 people undergo cataract surgery each year. The cataract operation has made considerable progress, both in terms of techniques and implants on the methods of anesthesia.
- The cataract operation may confine itself to remove cataract with conservation of the glasses.
- It can also currently be considered real refractive surgery and the opportunity for a ‘new youth’
By striking out glasses by far, reading, or any wearing glasses sunglasses. In this option it is not necessary to wait as cataract progresses and that vision down to perform the cataract operation, but it is possible to do it at an early stage in a relatively young subject since the main goal of the operation is the independence from glasses.
Is the cataract operation a safe operation today ?
Cataract, today, is not synonymous with blindness. Do not hesitate, first to consult as soon as you feel his sight down and then surgery cataract if such is the Council of the surgeon. It is pointless to wait when a cataract is scalable and vision fade knowing that no drug therapy or as eye drops, no change of glasses can prevent or delay the development of cataracts. Despite its current character and excellent results in the vast majority of cases advances in surgical technique and local anesthesia, this operation remains a delicate operation, not devoid of risks, such as any surgical procedure. The cataract operation must be perfectly controlled by a surgeon whose competence and experience impact heavily on the results. The quality of the equipment is as important to his patient’s recent acquisitions of modern technology that allows with a certainty of quickly restoring the view and lead a normal life.
The cataract operation has greatly benefited the development of implants
It now has implants capable of passing by all small incisions of 1 to 2 mm. Their optical quality improves. What are implants that protect the retina through better filtration of the solar radiation entering the eye more when we withdrew the cataract. Aspheric implants allow a reduction of frequent complaints after a cataract operation: glare, optical aberrations and the decrease of Visual quality in low light. They improve Visual performance when the light decreases with better contrast and a better appreciation of the moving objects. The arrival of new progressive multifocal implants used to correct presbyopia also allow the subject undergone cataract surgery to overcome very often glasses for far vision and reading with much fewer side effects than with the used implants up there.
We expected more now to perform a cataract operation that the Visual decline is very important.
The important success of the operation rate and reduced risk, technical conditions (local anesthesia, outpatient surgery with a few hours of hospitalization, very small incision for recovery of very rapid social life) explain that cataract be operated much earlier. We intervene as soon as the cataract progresses annoying more and more vision of the subject in his daily activities. The desire of the young subject wishing to refractive surgery, i.e. to overcome his glasses by far as to read encourages also operate more sooner to correct myopia, hyperopia and presbyopia associated with cataract.
It is usual to consider the cataract operation is indicated where Visual acuity is reduced to 4/10. In fact this notion is too restrictive: the notion of Visual quantity quantified in 10th, need to associate the quality of vision. The individuals harbouring a cataract often have a sharp decrease of twilight Visual acuity with decrease in contrast sensitivity dangerous for driving at the end. Other sensory needs are a function of the mode of life of every individual: more and more elderly people, for example, want to be able to travel, to drive long distances. This notion of individual Visual needs depending on the type of activity is an essential element to be taken into account in the indication of the operation of the cararacte.
What are the signs of cataract ?
Cataracts formed in general slowly and causes a decrease of progressive vision on several months or years. This poor vision cannot be corrected by glasses change since there is a Visual obstacle within the eye! It is often accompanied by a glare especially in vision backlit or when moving from light to dark and vice versa, a Halo around the light sources, a feeling of fog, greyish and dull, faded, less luminous objects, a vision double, a change in color vision. Often, changes in color vision become perceptible only after the operation. Yellowing of the lens reaches cataract filtering blue light, after the operation the blueus will be perceptible plius and the colors will be more saturated.
What are the causes of cataract ?
The most common cataract is due to ageing and occurs after the age of 50 years, sometimes sooner. It affects 10% of people below age 65, 30% of people 65 to 75 years, 50% between the ages of 75 and 85 70% after 85 years. The cause is not known but contributing factors have been highlighted. These are heredity, nutritional factors (malnutrition, alcohol, tobacco, hypertriglyceridemia), environmental factors (radiation solar solar exposure to UV protection and industrial pollution), certain eye diseases (glaucoma, myopia, uveitis), General diseases (diabetes, kidney failure, high blood pressure, deficit calcium or magnesium, prolonged corticosteroid treatment), and ocular trauma.
How long is a cataract ?
The clouding of the crystalline lens is usually phased over several years. In the vast majority of cases the vision by far is lowered while the reading remains as long as possible. Sometimes the posterior lens capsule is opaque, the Visual decline also affecting reading, is so fast in a few months.
How is a cataract treated ?
Of course, change of glasses can not remove the opacity of the lens. There is not, at present, of medical treatment that has demonstrated a real efficiency despite the multitude of eyedrops and systemic treatments marketed. The only current treatment is therefore surgery: it is to remove the clouded lens to restore the clarity of the optical axis and replace it with an intraocular implant. The number of interventions for surgery of cataract per year increases significantly. There are many reasons for this increase:
- Improvement of the techniques of surgery that allowed to expand the indications with a high rate of satisfaction for patients.
- Desire to active life of the elderly who want a better life particularly as regards driving.
- Ageing of the population.
At what moment should carry out the operation of cataract ?
We expected more now that cataract is “ripe” and the blind patient. The current important success of this surgery rate explains that it operates much earlier. We intervene once the cataract plays annoying more and more vision of the subject in his daily activities. The procedure is therefore indicated where the clouding of the crystalline lens is such that the patient sees more well enough. Indeed, it is useless to expect: without operation cataract will come more dense and the worst vision will increase the concern of the topic.
It is usual to consider the operation is indicated if Visual acuity is reduced to less than 5/10. In fact this notion is far too restrictive: the notion of Visual quantity, it is becoming increasingly common to substitute the quality of vision. The individuals harbouring a cataract often have a sharp decrease of twilight Visual acuity with decrease in contrast sensitivity dangerous for driving at the end. Other sensory needs are a function of the mode of life of every individual: more and more elderly people, for example, want to be able to travel, to drive long distances. This notion of individual Visual needs depending on the type of activity is an essential element to be taken into account in the surgical indication of the cataract. The operation becomes also more delicate when the cataract is advanced and less predictable when success the retina is inexaminable because of the important clouding of the crystalline lens. Fear of surgery on the eye body seen as highly sensitive and noble should not delay the solution of the surgery.
Outpatient surgery. Operation of cataract in an elderly person.
Even if performing the cataract operation more and earlier, the age is not an obstacle to the cataract operation. There is no age limit for surgery of cataract with current surgical techniques with local anesthesia: a century-old person can easily be operated. The operation of cataract can be practiced more often under local anaesthesia anaesthetic eye drops (topical anaesthetic) or by a small painless injection to the corner of the eye. General examinations must be performed before the cataract operation: biological, electrocardiogram. A consultation by the anaesthetist is essential a few days at least before the operation. Usually the patient between the day of the operation. It will be released the same day after a few hours in outpatient surgery for very short hospitalization-mode or the next day if desired for reasons of personal amenities.
Is the result of the cataract operation always favourable ?
After a cataract surgery, in the vast majority of cases, the vision is usually already very improved after a few days. However the vision that one can hope to recover after cataract surgery depends on the State of the retina and the optic nerve. If they are normal Visual recovery will be excellent. But if the optic nerve is already reached by glaucoma or the Central retina suffers from macular degeneration, Visual recovery after cataract operation will be less. The association attended a cataract and degeneration macular in the elderly often poses the problem of estimating the value of recoverable Visual acuity after cataract surgery.
Can we do without glasses after cataract surgery ?
If the choice is a classic mono-focal lens, it is possible to obtain after cataract surgery either vision from afar or near vision without glasses whether you are nearsighted, hyperopic or Emmetropic. Progressive multi-focal implants allow to overcome very often glasses for far vision and reading with much fewer side effects than with the used implants up there. Obtaining a good visual acuity without correction through the mastery of astigmatism. In the case of astigmatism net superior to 1.25 d, wearing glasses correcting this astigmatism will be necessary to obtain a good far vision. However, the correction of astigmatism is possible during surgery: either at the level of the cornea (micro-incision, choice of the incision site, relaxing incisions, or by the use of an o-ring implant correcting astigmatism.
What are the progress achieved and expected in the cataract surgery ?
A reduction of the complications of the cataract operation. The cataract operation may know complications, infectious or technical. Infectious complications of cataract surgery are rare, approximately about a transaction 1,000. Reducing this risk through better organisation of operating blocks, particularly thanks to certification (Iso 9000) methods that establish specific aseptic protocols. A rigorous methodology of infection support allows to limit the consequences. Other complications of the operation of cataract (1-3%), are related to a rupture of the posterior lens capsule and are more or less serious (edema macular retinal detachment). Their reduction passes by better training of surgeons and a refinement of the machines.
The evolution of the material used during the cataract operation
- The devices of last generation are much safer as they ensure a better control of the pressure in the anterior Chamber of the eye. These are, indeed, pressure variations that are more often responsible of the posterior capsule rupture during cataract operation.
- Another cataract operation is in its infancy, the Aqualase, whose principle is to use the water to emulsify the cataract. This operation is less traumatic for the posterior capsule and does not cause an overheating of the cornea.
- There are new techniques of cataract operation by micro-incision for less to undermine the eye by reducing the size of the incisions to minimize induced astigmatism. Biaxial micro-incision technique uses two incisions of 1.5 mm, coaxial micro-incision technique uses a single incision 2.2 mm or even smaller.
The choice of the implant
- To reduce the incidence of posterior capsule opacification after cataract surgery it is possible to use implants to square edges, rear angulation, acrylic hydrophilic or hydrophobic.
- Contributing to the protection of retinal implants with blue light filter. If all marketed implants are currently equipped with a filter protecting from ultraviolet light, another development to incorporate a filter for the wavelengths of light in the blue, potentially toxic for the retina.
The quality of vision
Cataract surgery has become a refractive surgery. The accuracy of the correction is no longer enough, some patients with a satisfactory Visual acuity may complain of gene in low brightness, glare, contrasts vision decline. Aspheric implants aim to reduce these disorders. They improve the Visual when the light decreases and performance night with a better contrast and a better appreciation of the moving objects.
The evolution of implants
The problem remains that of implants because there is now little able to go through these tiny implant incisions; the future of the cataract operation therefore goes through the development of more manageable implants. Their optical quality improves. There are already protective implants of the retina through a better filtering of the radiation. New aspheric implants allow a reduction of optical aberrations. The imminent arrival of new biomaterials should further improve the results. Mainly: the phaco ersatz, intelligent intraocular implant (smart IOL), the adjustable implant in the light, or light absorber, equipped with a diaphragm lenses, as well as lenses very permeable to be placed in the thickness of the cornea for refractive surgery.
The femto-second laser assisted cataract surgery
It’s a beginning to be used in 2012 new technique that allows the use of the laser for some manual time of the usual surgical technique: the incision of the cornea, cutting of the anterior capsule of the crystalline, the fragmentation of the nucleus and the incisions for astigmatism correction. The laser allows a better accuracy for the realization of these operating times. It is therefore always a non-surgical technique of usual risks in particular capsular rupture with fall of cristalliniens fragments in the vitreous. The operation is longer and more costly which should curb the dissemination of this technique. Further studies are needed to assess the medical added value of this new procedure.