Prof. Mimouni has extensive experience in cataract surgery of all types, including femtosecond laser assisted cataract surgery. In addition, the artificial lens implanted during surgery can be tailored to the patient’s needs, including premium lenses such as toric and/or multifocal intraocular lenses.
What is a cataract?
When we are born, the natural lens in our eye is clear. A cataract is a condition in which the lens loses its transparency. The most common cause of cataract formation is age, and this type is known as age-related cataract. In most cases, the cataract becomes significant after the age of 60.
A cataract is not something you catch, and it is not something that can be halted with drops. It is a gradual change in the structure of the proteins inside the lens. There are causes other than age as well: trauma to the eye, prolonged steroid use, poorly controlled diabetes, previous intraocular surgery, and rarely congenital cataract in infants.
What are the symptoms of a cataract?
The most common symptoms are blurred vision, glare, sensitivity to light, faded colours (everything looks slightly greyer), and a sudden improvement in near vision. In addition, frequent changes in your eyeglass prescription may indicate a developing cataract.
Two things are confusing here. The first is that glare becomes disturbing long before the measured visual acuity looks poor — people struggle to drive at night while in the clinic they still read small lines. The second is the temporary improvement in near vision, which comes from a shift in the power of the clouding lens. That is not a good sign; it is a stage in the process.
When is it time to operate?
The short answer: when the vision interferes with function. Not when the cataract reaches a particular grade on examination, and not when it has “ripened” — that term belongs to an era when the surgical technique was entirely different, and today it is mostly a source of confusion.
In practice, the questions I ask in the clinic are practical ones. Has night driving become uncomfortable or frightening? Is it hard to read, to recognise faces, to work at a screen? Does the glasses prescription keep changing without that helping? Does the vision still meet the requirements for a driving licence? The answers to those questions determine the timing far more than the appearance of the lens at the slit lamp.
There is another side to it. Waiting a long time is not dangerous in most cases, but it does make the surgery more complex: a hard nucleus requires more ultrasound energy, which slightly raises the risk of complications and lengthens recovery. In certain situations — for example when the cataract prevents adequate monitoring of a retinal disease — there is a medical reason to operate earlier, even if the functional impairment is still mild.
How cataract surgery is performed
At present, surgery is the only effective treatment for cataract. Prof. Mimouni performs cataract surgery at Rambam Health Care Campus. For a pre-operative evaluation, please ask your ophthalmologist for a referral to the ophthalmology outpatient clinics at Rambam Health Care Campus.
What happens during the surgery
The lens is made up of several parts: the nucleus is the central part of the crystalline lens, which hardens over the course of life. Surrounding it is the cortex. The entire lens is enclosed in a thin capsule, which usually remains clear. The lens is supported within the eye by fine fibres called zonules, which are attached to the ciliary body.
During modern cataract surgery, a small 2-3 mm incision is made at the edge of the cornea. A circular opening is then created in the anterior lens capsule. The lens material is broken up using high-frequency ultrasound, a technique called phacoemulsification, and aspirated out of the eye. Apart from the central circular opening in the anterior portion, the capsule remains intact within the eye, and it is thoroughly cleaned and polished. An artificial lens is then folded, inserted through the small side incision, unfolded, and positioned within the capsule. The lens is selected based on biometry measurements taken before surgery. The small incision seals itself and usually does not require sutures. The surgery typically takes about 15 minutes.
What the artificial lens looks like
Intraocular lenses are usually made of acrylic material (a type of plastic) or silicone. The optical portion is typically 6 mm in diameter. In most cases there are 2 or 4 haptics (small arms) attached to the optical portion that stabilise the lens within the capsule.
Which lens to choose is a separate question, and it is the most significant decision the patient takes part in. I have devoted a full page to it: how to choose a lens for cataract surgery — the difference between monofocal, toric, multifocal and extended depth of focus lenses, the real numbers on halos and glare, and who a premium lens simply does not suit.
Can every eye take an artificial lens
Intraocular lenses can be implanted in almost any eye, and they are very well tolerated. Only very rarely is it impossible to implant a lens within the capsule — for example when the zonules are weak — and in that case there are alternative ways of fixating the lens elsewhere in the eye. In most cases this becomes apparent at the examination before surgery.
Preparation and anaesthesia
Cataract surgery is usually performed under local anaesthesia. If, for special reasons, you require surgery under general anaesthesia, you will need an evaluation by an anaesthetist confirming that you are fit for general anaesthesia, possibly at a separate visit.
In most cases, you will arrive at the hospital a few hours before surgery on the day of the operation. You may eat your meals and take all of your regular medications as usual. About an hour before the actual surgery, you will receive eye drops to dilate the pupil and, if you wish, medication to help you relax. You will then be taken to the operating room.
The surgery is performed under topical anaesthesia (eye drops only) or regional anaesthesia (a small injection around the eye), which makes it a painless procedure. You are awake throughout, you see light and movement but not the surgery itself, and you can speak with the team.
Recovery: what happens after surgery
The operated eye is covered with a protective shield. After surgery it is advisable to rest a little, but you do not need to stay in bed — you can move around as usual straight away. With very few exceptions, cataract surgery is performed on a day-surgery basis, so you can leave the hospital about an hour after the operation.
Most people notice an improvement within the first day or two, but vision stabilises gradually. During the first weeks you use antibiotic and anti-inflammatory drops on a set schedule, and that is the most important part of recovery. In that period you avoid rubbing the eye, swimming and dust, and you keep the shield on while sleeping for the first few days.
A gritty or dry sensation in the weeks after surgery is common and usually passes. It comes from the corneal incision, from the drops themselves and from the preservative in them. In anyone who had dry eye before the surgery, the sensation can be more pronounced and is worth treating alongside.
A new glasses prescription is written only once the refraction has settled, usually about four to six weeks after surgery. There is no point ordering new lenses before then.
Risks and complications
Cataract surgery is one of the safest and most common operations in medicine, but it is surgery, and so it carries risks. It is important to know them in advance rather than discover them afterwards.
- Intraocular infection (endophthalmitis) — the most serious complication, and very rare: fewer than one in a thousand operations. It is treated urgently, which is why any severe pain or sudden drop in vision in the days after surgery requires immediate attention.
- Posterior capsule rupture — the more common intraoperative complication. It is managed during the same operation and usually does not change the final outcome, but it can change the type of lens implanted and the length of recovery.
- Swelling at the centre of the retina (macular oedema) — causes blurring that appears a few weeks after surgery, and usually responds well to treatment with drops.
- A rise in intraocular pressure — usually temporary, and monitored at follow-up visits.
- Refractive surprise — the vision is good, but the final prescription is not exactly what was planned. Biometry is highly accurate but not perfect, particularly in unusually long or short eyes or after previous laser surgery.
- Retinal detachment — rare, and more common in high myopia.
The most frequent thing that happens after cataract surgery is not a complication of the surgery at all but a later process: in some patients the capsule left in the eye becomes cloudy, months or years afterwards. This is called secondary cataract, it is not a new cataract, and it is treated with YAG laser capsulotomy — a brief clinic procedure, with no incision and no hospital stay.
What the public health basket covers
Cataract surgery itself, including a standard monofocal lens, is covered by the public health basket in Israel. What is not covered is the upgrade to a premium lens — toric, multifocal or extended depth of focus. The contribution towards that upgrade varies between health funds and between levels of supplementary insurance, and it is the main reason for the differences people run into.
I have set this out separately, including what each fund says and which questions are worth asking before agreeing to an offer: the cost of cataract surgery and premium lenses.
Evaluation and treatment with a specialist
The decision to have cataract surgery is a functional one, not just a number on a test. At the evaluation we assess how much of the complaint the cataract actually accounts for and how much comes from other causes, measure biometry in order to plan the lens, and consider what is realistic to expect from it in that particular eye.
If you are considering cataract surgery, or have been given a recommendation and would like a second opinion, get in touch.
Frequently asked questions
When is it time to have cataract surgery?
When the vision interferes with daily function — night driving, reading, recognising faces, work. There is no need to wait for the cataract to "ripen": that idea belongs to an era when the surgical technique was entirely different. On the other hand, waiting a very long time makes the nucleus harder and the surgery more complex.
How long does cataract surgery take?
The surgery itself usually takes about 15 minutes. The total stay at the hospital is longer, because you arrive a few hours in advance for preparation and usually leave about an hour after the operation. It is day surgery, almost always under local anaesthesia.
When does vision come back after cataract surgery?
Most people notice an improvement within the first day or two, but vision stabilises gradually over several weeks. A new glasses prescription is written only once the refraction has settled, usually about four to six weeks after surgery.
Are both eyes operated on the same day?
Usually not. The convention is to operate on one eye, confirm that recovery is normal, and schedule the second afterwards. The gap between the two is generally kept short, because a large difference in prescription between the eyes during the interval can be uncomfortable.
If I have had cataract surgery, can the cataract come back?
The lens that was removed does not come back. What does happen in some patients is that the capsule left in the eye becomes cloudy over time, a condition called secondary cataract. It is not a new cataract, and it is treated with a brief laser procedure in the clinic rather than further surgery.
Is cataract surgery covered by the public health basket?
The surgery itself, including a standard monofocal lens, is covered by the public health basket in Israel. What is not covered is the upgrade to a premium lens — toric, multifocal or extended depth of focus. The contribution towards that upgrade varies between health funds and between levels of supplementary insurance.