Cataract

A cataract is a cloudy lens that causes the vision to become misty and foggy. In the early stages cataract can sometimes cause short sightedness. The cloudiness gets worse until the vision is too foggy to see, but most people have the cataracts operated on well before this. Cataracts are common and up to 60% of all 60 year olds having some early signs of cataract and 100% of those over the age of 80 having some cataract. The symptoms of cataract include blurring of vision and glare in bright or sunny conditions. Cataracts only need to be operated on if they are causing visual problems. The main cause of cataract is genetic, it runs in families. There are other causes of cataract such as injury, the use of steroid tablets, steroid inhalers and creams (around the eye) as well as other eye diseases and previous eye surgery. Sunlight may have a role in the aetiology of cataract although this has not been proven.

The procedure is usually carried out as a day-case procedure under local anaesthesia, often with a small amount of short-acting sedation and it is not painful (no needles!). The surgery typically takes 15-20 minutes. In cases of bilateral cataract, both eyes are not usually operated on the same day, but 1-2 weeks apart. Mr Ionides operates on Thursday mornings with the list beginning at 10.30am and patients are admitted to the Cumberlege Wing on the top floor of the main Moorfields Eye Hospital at about 9am on the day of surgery.

After the surgery, patients have an eye patch protecting the operated eye and return to the ward. The nursing staff will give them the post-operative drops and discuss what they can and cannot do in the next few days/weeks owing to the surgery. It is generally recommended to have a week off work following the surgery although most people are able to carry on with most daily tasks after a couple of days. Some of the drops can sting for a few seconds, particularly the Acular and Maxidex drops. Occasionally the eye can be painful in the few hours after surgery, but simple pain relief tablets when you get back home can help with this. Mr Ionides will call you the next day but you will have his mobile number in case of any questions. There will also be one or more follow up appointments back in the clinic for the post-operative scans and refraction.

The femtosecond laser is sometimes used during cataract surgery and performs some of the steps involved in cataract surgery. Moorfields has a femtosecond laser for use with cataract surgery and is currently in the process of undertaking a study into the risks and benefits of the femtosecond laser in cataract surgery. If you have any questions about the surgery or your suitability please email Alexander Ionides or call Leigh McEvoy on 02075662414. For further information visit our FAQ page.

………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

Laser refractive surgery

Laser surgery uses an Excimer laser to reshape the cornea and so treat short sightedness (myopia), astigmatism and some cases of long sightedness (hypermetropia, hyperopia). It cannot treat presbyopia, which is the need for reading glasses when people reach their mid to late 40s. For some presybopic patients monovision is an option. This will be briefly discussed below. There are two main types of laser surgery.

  1. LASIK (IntraLASIK). A thin corneal flap is created with a femtosecond laser, the underlying cornea is then lasered with the Excimer laser to reshape the cornea and the flap is then replaced. The vision usually settles down and recovers over the next 4-6 hours, although complete healing takes weeks to months.
  2. Surface treatments such as LASEK or PRK. In these treatments the outer layer of cells (epithelium) is removed from the cornea, the underlying corneal tissue is then lasered with the Excimer laser and the epithelium grows back over the next 3-4 days and the vision gradually recovers over the ensuing days to weeks. People usually need a week off work for the surface laser treatments.

The laser treatment that is best suited to any particular person can be decided after scans to assess the corneal thickness and the shape of the cornea. Laser has been shown to treat up to -10D of myopia and up to +6D of hypermetropia (although hypermetropic -longsighted, treatments can be less successful and risk regressing). Successful outcomes in myopes are more predictable up to -8D and in all hypermertopes there is a high risk of the long sightedness returning. This is less so with the low hypermetropes up to +2D. For the laser treatment of patients who are short sighted or long sighted, but also presbyopic ie older than 45 years of age, correcting the distance vision will leave most people naturally needing reading glasses. This can be overcome in some cases by having one eye corrected for distance and the other eye corrected slightly for near – a method referred to as monovision. This can be discussed in more detail in your clinic appointment if indicated. It may be that clear lens extraction and insertion of a multifocal lens may be indicated in some presbyopic patients. Contact lenses may also be an option. The risks of laser surgery are included in the detailed consent form which is in the link below. For any questions or thoughts please make contact using the details given in the contacts page or for further information visit our FAQ page.

………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

Clear lens extraction

Also known as PreLex (presbyopic lens exchange), Clear lens extraction is essentially cataract surgery (it is worth reading the cataract information above). It is the method of choice in patients who are in their 50’s and older who want to have glasses-free vision for both distance and reading but need glasses for both. If you have good unaided distance vision but need glasses for reading then clear lens extraction is not recommended for you. Removing the natural lens and implanting a multifocal lens aims to give good unaided distance vision as well as glasses free reading for most print, but people will still occasionally need glasses for very small print. This will not deteriorate with age and the lenses will never need replacing. About a third of patients will at some point develop posterior capsular thickening, which is a membrane that naturally forms behind the lens implant, but is easily treated with a ‘YAG’ laser and is utterly painless. Many multifocal lenses can give rise to glare, haloes or ‘ghosting’. Mr Ionides uses either the Zeiss trifocal multifocal lens or the Mplus ‘Comfort’ lens. For further information visit our FAQ page.