What is a Cataract?
A cataract is an opacity or cloudiness that develops in the lens of the eye. The lens lies inside the eye behind the iris (the coloured part of the eye) and its central hole, the pupil. This cloudiness will restrict light from entering the back of the eye to reach the retina and will impair vision. If left untreated, cataracts will usually continue to develop until vision is completely obscured and the eye is blind.
Cataracts are a natural feature of aging. The older one gets, the greater the chance of developing cataracts. However, they can occur at any age and may be accelerated or caused by ultraviolet radiation, the effects of diabetes, medications such as steroids and as a result of inflammation within or injury to the eye.
Symptoms of Cataract
Cataracts may advance quickly but usually develop gradually over a period of several months or years and sometimes at different rates in each eye. Since there is no pain the changes at first may not be noticed, but early symptoms include:
- Blurred Vision - Changes to sight can include fuzziness and lack of clarity, with a washed out appearance.
- Depth Perception - Cataracts may develop more quickly in one eye than the other. As one eye can still see clearly, many people unconsciously rely on it and fail to notice the poor vision in the other. Reliance on one eye affects their perception of depth and they misjudge distances - a particular problem when driving a car or playing sports, such as golf.
- Colour Reduction - Changes in the lens may lead to impairment of colour perception, particularly the loss of ability to see blues and purples.
- Night Blindness - The cloudiness of the lens allows less light to enter the eye, this increases difficulty in seeing at night or in dim light.
- Glare - Cataracts may cause light to scatter as passes through the lens, giving the appearance of a halo or streaks around lights.
- Short-sightedness - As some cataracts develop, they increase the power of the lens and its ability to bend (refract) light. This increase in refracting power can make the eye more short-sighted.
- Double/Triple Vision - Some cataracts will split the light as it passes through the lens and can produce double vision or even the appearance of multiple images in one eye.
The Treatment of Cataracts
Only a few decades ago, cataracts condemned sufferers to a life of near total blindness. Due to limitations in surgical techniques, cataracts were typically only operated on when they were very dense and "mature" and the patient virtually blind. Complications were not uncommon and thick glasses or contact lenses were often required following surgery in order for the patient to see.
Today, thanks to the development of artificial intraocular lenses and "key-hole" (small-incision) surgical advances such as phakoemulsification (ultrasound lens liquefaction), cataract removal in experienced hands is one of the safest forms of surgery with excellent results. In the US alone, over 1,250,000 procedures are performed per annum. Most people regain their lost vision within a day of surgery and the quality of life experienced before they developed cataracts. Only very rarely is the final result compromised, usually by other non-treatable ageing or pathological conditions, such as macular degeneration. The benefits associated with modern cataract surgery are numerous and there is now no need for anyone to change their lifestyle as a consequence of developing cataracts.
The Cataract Operation
Under local or general anaesthetic, a small incision, less than 3mm, is made into the eye and the cataract is removed allowing light to pass once more into the back of the eye. To restore the focusing properties of the eye, the removed cataract is replaced by a permanent artificial intraocular lens, about the size of the Queen's head on a penny coin. The lens is not sutured within the eye, but rather sits in the same structure as did the natural lens and once in place the eye does not reject it.
The Intraocular Lens Implant - Prior to surgery a number of measurements of the eye are made, which are necessary to calculate the power of the artificial intraocular lens implant required for optimum post-operative vision. Most of the artificial lens implants are monofocal i.e. they have only one power, or length of focus. By choosing the right lens it is often (but not always) possible to correct any pre-existing long or short sight, so that after surgery only reading glasses are required. Over recent years intraocular lens implants have continued to evolve and improve with advanced aspheric and toric (astigmatic) optics designed to optimize post-operative vision especially in low levels of illumination. It is Professor O'Brart's preference to always use such lenses where possible.
Accommodative and Multifocal Intraocular Lens Implants - Newer lens designs have been developed (multifocal and accommodative lenses) that now may allow patients to see well in the distance while retaining some near vision. Whilst such lenses are at a developmental stage, results have been generally encouraging. Professor O'Brart has conducted a research project investigating the efficacy of the "Tetraflex" accommodative lens and HumanOptic "Diffractiva" multifocal lens. He has over a decade of experience with multifocal lenses, including the Alcon "Restor", Oculolentis M plus, Zeiss AT LISA trifocal lens, PhysIOL Finevision Trifocal lens, Alcon PanOptix and Symfony extended range of vision lens.
Based on the scientific literature and his own experience, Professor O'Brart's current lens choices are implantation of the new trifocal type lenses or the Symfony extended range of vision lens with a micro-monovision technique. His experience with these lenses is that more than 95% of individuals do not require spectacles either for distance, intermediate or near vision with bilateral implantation. There is, however, a chance of glare and halo phenomena around lights especially at night although severe problems, requiring removal of the lens, occur in less than 2%. Further details of such specialised lenses plus their risks and benefits can be discussed during the pre-operative consultation with Professor O'Brart.
Phakoemulsification (small-incision) Cataract Surgery - This is the currently preferred "gold-standard" technique. A tiny, vibrating ultrasonic needle is used to liquefy and remove the cataract through a small-incision of approximately 2mm. After the removal of the cataract, foldable, artificial intraocular lenses can be implanted into the eye without having to enlarge the incision. Because the incision is small, it is usually self-sealing and typically no stitches are required.
The benefits of Phakoemulsification, small-incision, no-stitch surgery include:
- Quicker healing time;
- Minimal post-operative astigmatism;
- Ability to remove cataracts safely and effectively at an earlier stage and no need to wait until the cataract is "mature"
- The integrity of the eye is minimally affected and the patient can return to normal activities almost immediately
- Fewer post-operative consultations are required and the risk of post-operative infection is reduced.
Irrespective of the technique chosen, most cataract operations are treated on a day case admission basis, although overnight stays can be arranged if preferred. The procedure can be performed either under a local or general anaesthetic depending on patient preference and any pre-existing medical conditions.
Femtosecond Laser Assisted Cataract Surgery (FLACS)
Femtosecond lasers have been introduced into cataract surgery over the past 5 years to offer an enhanced degree of precision in some of the superficial steps in the cataract surgery procedure, such as astigmatism cuts, the opening in the front skin of the lens (the capsulorhexis) and the division of the hard lens centre (its nucleus). Professor O'Brart has extensive experience of such lasers for cataract surgery (and has treated many hundreds of patients with FLACS) and is currently undertaking research into the possible implementation of such technology into the National Health Service to improve efficiency and patient safety.
Secondary Cataracts (Posterior Capsular Opacification)
Whilst cataracts do not re-appear after they have been removed, for some patients vision can become fuzzy and deteriorate again months or years after successful cataract surgery. During cataract surgery the natural "bag" of the lens – its capsule - is not removed as it is required to support and position the new artificial intraocular lens. It is this bag that can, in some individuals, become cloudy and reduce vision. If this happens, it is very easy to reverse by making an opening in the "bag" with a laser (the YAG laser). This is a totally painless procedure and can be performed in a matter of minutes.
Information for Patients Booked for Cataract Surgery
Prior to surgery, the curvature of the cornea is measured and the length of the eye determined by ultrasound, known as A-Scanning or more commonly by optical methods. This is necessary to calculate the power of the artificial intraocular lens implant required for optimum post-operative vision. By choosing the right lens it is often, in 90-95% of cases, possible to correct any pre-existing long or short sight, so that after surgery only reading glasses are required. It is also possible to reduce astigmatism (a condition where the cornea is slightly "rugby-ball shaped") at the same time as conducting cataract surgery by performing small partial thickness cuts in the periphery of the cornea or inserting a special toric (astigmatism correcting) intraocular lens. If this is the case, Professor O'Brart may arrange for you to have a scan of the surface of your eye (corneal topography).
If patients are scheduled for a General Anaesthetic, they must not eat or drink anything for nine hours before the operation.
If patients are to have only a local injection or topical anesthesia a light meal up to four hours before is acceptable. If admission to hospital has been scheduled for example at 8.00 am, the patient need only avoid eating breakfast, but if admission time is in the afternoon, a light breakfast may be eaten and then nothing else until after the operation.
All valuables should ideally be left at home and eye make-up should not be worn to hospital. As the eyes may be sensitive to sunlight after surgery, it is advisable to bring sunglasses.
Any medications, other than eye medication, should be continued, unless advised to the contrary by the eye surgeon. All current medications should be taken to hospital, as the anaesthetist may wish to see them.
Patients, who are staying over-night in hospital, will need to bring nightclothes and toiletries. Day case patients will not usually be required to change into a hospital gown, so loose fitting, comfortable clothes should be worn to the hospital.
Prior to admission, all patients should arrange to be collected from hospital as they must not drive themselves home following surgery.
Upon arrival at hospital
Patients should report to the hospital reception desk or private patients' office at the time advised. Admission details will be sent by the hospital prior to admission. For private patients, if they have private health insurance, the hospital will require details of the insurance cover otherwise payment is required in advance. Following registration, patients are taken to either a cubicle in the day ward or to their room where they are prepared for treatment and will meet the anaesthetist (if applicable).
Prior to general anaesthesia, most anaesthetists require all patients, over the age of 60, to undergo precautionary health checks, comprising an ECG, chest x-ray and blood tests and, if these had not previously been performed, then they will be done on admission and prior to surgery.
Preparation for treatment
During the hour prior to surgery the eye will be prepared for surgery and eye drops will be administered - these are quite painless. They include drops to dilate the pupil.
The operation may be carried out under local or general anaesthesia and unless there is any specific medical reason for either one, the decision is usually left up to the patients themselves. Most cataract operations are now performed under topical anaesthesia with eye drops only or by sub-tenon's local anesthesia, where a tiny nick is made in the conjunctiva at the bottom of the eye and a blunt needle is used to inject anaesthetic behind the eye. Such techniques allow patients to be discharged and return home within an hour or so after surgery.
The administration of local anaesthesia causes little or no discomfort. No needles are put into the eye itself and once the anaesthetic has taken effect, no pain will be felt, although there may be a general awareness of movement of the eye.
The operation usually takes between 15-20 minutes, following which a plastic shield is placed over the operated eye before patients are accompanied back to their cubicle/room where family or friends may join them.
Even when the operation is performed under general anaesthetic, most people find that they are ready to leave hospital within a couple of hours of surgery, although it is suggested that they rest quietly for 1-2 days following their operation. Before leaving patients are asked to make an appointment for the first post-operative consultation, typically the following day, and given eye drops containing cortisone and antibiotics to administer for several weeks, whilst the eye is healing.
Unless advised otherwise, patients may begin eating normally at any time after the operation, although it is sensible that the first meal is a light one. All prescribed medications should continue to be used after leaving the hospital.
Post-operative vision varies from one patient to the next. Typically with small-incision techniques an improvement in vision is noted within 12-24 hours of surgery. Occasionally, vision may initially be a little blurred and improve progressively over the first few weeks. The operated eye may appear red for the first 2-3 days following surgery, but this is quite normal and once the eye has settled down it will look clear and healthy. There is usually very little pain after surgery although for a few days it may feel slightly bruised - a sensation similar to having grit in the eye.
Post Operative Care
- Do not rub or press the operated eye and wear the eye shield provided for the first 7 nights to avoid inadvertently rubbing it whilst asleep. Try to sleep on the side not operated upon
- Patients must rest for the first 7 days after surgery, thereafter all normal activities can be resumed, but please take care when around small children and animals
- Patients may shower, bathe and wash their hair whenever they wish, but avoid getting dirty or soapy water in the operated eye for the first two weeks
- If the eye becomes sticky, the eyelids may be gently bathed with cotton wool balls and cooled boiled water
- Keep all follow up appointments and take medication as directed
Post operative Consultations
Patients will be asked to attend their first post-operative visit on the day following surgery. Post-operative check-ups help the doctor to monitor the healing and visual progress, as well as providing the patient with the opportunity to ask any questions they may have.
Most people only require two or three post-operative visits in the first eight weeks and overseas patients may return home after 3-5 days. All eye drops should be brought to each post-operative visit.
In Case of Emergency
Modern cataract surgery is an extremely safe operation, affording excellent results. However no surgical procedure, even modern cataract surgery, is guaranteed to be without complications and problems may occur, albeit rarely.
In the unlikely event of a post-operative problem, please call Professor O'Brart's office on 01702 586656.
Do not wait for the next appointment if any of these conditions are experienced:
- Sudden worsening of vision
- Onset of pain in the eye which will not go away
- A sensation of flashing lights in the eye
- The development a shadow in the vision
- The eye becomes more red and sticky
- A pus-like discharge from the eye
It is important that patients use the eye drops provided as prescribed during the post-operative period.
How to use eye drops:
- Wash hands and shake the bottle well
- Tilt head back, open eye and look up
- Gently pull lower eyelid down to form a pocket
- Squeeze one drop into the pocket formed, being careful not to touch the eye
- Gently close the eye holding the lower lid out
- Release the eyelid and blink a couple of times
- Gently wipe away any excess liquid with a clean tissue
If this procedure is difficult, try looking in a mirror or else lie down and tilt the head back with the eyes wide open. Put the drop in the corner of the eye by the nose then, keeping your eyes open, roll the head from side to side.
After cataract surgery with the implantation of an artificial intraocular lens, a patient's old glasses are typically ineffective. Depending on the technique used, patients can either visit their Opticians or will be provided with a new prescription for glasses at their five-week consultation. In the meantime, old glasses can continue to be worn or an Optician can be asked to replace the lens for the treated eye with a blank lens. The majority of patients require only reading glasses after cataract surgery.
Information contained on this website is intended as a guide only. Always seek professional advice before ANY treatment.
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