All you need to know about cataract surgery
All you need to know about cataract surgery by Consultant Ophthalmologist Jonathan Ross.
Modern cataract surgery – the basics
Cataract surgery has been evolving and progressing continuously since the modern version of the procedure was introduced in 1949 in London. Today surgery is minimally invasive with more than a 99% success rate. General anaesthetic is only rarely required, and the procedure often takes as little as 10 minutes, with less than a half day required in hospital. Patients often think surgery is carried out using a laser, but actually modern cataract surgery uses a tiny ultrasound probe similar in size to the lead of a pencil. During surgery the eye is numbed so you do not feel pain, and the eyelids are held with a special clip so you cannot blink or close them. A 2-millimetre incision is made at the edge of the cornea to allow access, and the whole operation is done through this cut. The shape of the incision means that after surgery the incision will automatically seal tight without the needs for any stitches (sutureless cataract surgery). As a result, patients can resume most normal activities within a few days. Fourty years ago incisions were much larger and patients needed to remain still in bed for several weeks after surgery while wounds started to heal. The cataract is carefully removed from behind the dilated pupil with the ultrasound probe, and an artificial lens is inserted into position in the same place to allow for good vision. Following lens implantation the eye is filled with a clear antibiotic solution and then surgery is complete. Vision takes a few days to clear due to four factors. Firstly, the pupil dilating drops given before surgery blur vision and take a day or two to wear off. Secondly you will at first be dazzled by the brightness of the operating microscope light. Thirdly the clear plastic shield worn over the eye can blur vision, and finally the antibiotic ointment applied to the eyelashes at the end of surgery can make vision very blurred. Once these four factors have been removed, vision should be good. Expect to use drops four times daily for four weeks after surgery to improve the healing of the eye.
Major milestones in modern cataract surgery
Cataract surgery in its current form is 70 years old. During that time there has been a major innovation approximately every decade which has greatly improved outcomes. Here is a list of the 10 biggest improvements to cataract surgery during that time.
1. In 1949 surgeons started replacing the cataract with an artificial lens implant. This meant that patients no longer needed to wear very strong spectacles after cataract surgery.
2. Refinements to lens implant design in the 1960’s overcame many of the problems associated with early lens designs.
3. Introduction of ultrasound probe technology in the 1970’s meant that cataracts could be dissolved inside the eye, and incisions could be made much smaller.
4. In the 1980’s a more controlled technique for opening up a cataract known as a ‘capsulorhexis’ was devised. This led to less damage inside the eye and better positioning of the lens implant.
5. In the 1980’s the introduction of blunt cannula anaesthetic meant that some of the rare but serious complications of sharp needle anaesthetic could be avoided.
6. Development of folding lens implants in the 1980’s meant that cataract surgery could be carried out with even smaller (3-4mm) incisions.
7. In 1999 the first presbyopia correcting lenses were introduced in USA. These allowed for the correction of near and distance vision without the need to wear spectacles. Initially three different lens designs were introduced. These early multifocals worked well but often had problems with night time glare. The last 20 years have seen marked improvements in multifocal lens design.
8. Development of memory polymer injectable lenses has allowed the average incision size for cataract surgery to reduce to 2mm.
9. Introduction of antibiotic solutions which fill the eye at the end of cataract surgery has greatly improved safety. The incidence of serious infection after surgery has now reduced from one in a few hundred to one in a few thousand in experienced hands.
10. Preoperative eye measurements are much more accurate than ever before, allowing surgeons to calculate the correct strength of lens implant with higher levels of accuracy than in previous years.
Future goals for cataract surgery – where will cataract surgery be in 50 years time?
Welcome to the final instalment in our three-part blog by Consultant Ophthalmologist, Mr Jonathan Ross. In the article, Jonathan predicts the innovations that are likely to come about in cataract surgery over the next half century.
As cataract surgery gets better and safer, more attention will turn to having surgery at an early stage, and expectations of having good vision without spectacles will increase. Several multinational organisations are also investing large sums of money into lens development with functionality beyond good optics. Here’s my list of innovations we can expect during my lifetime.
- Serious eye infections will be almost eliminated. Further reductions of incision size, new refinements to sterile technique, closer postoperative scrutiny and a better understanding of the process of toxic and inflammatory damage during infection will lead to serious infections occurring in only one in every tens of thousands of cases. This might mean that most eye surgeons never see a serious eye infection in their career.
- Further research will make lens power calculations more and more accurate so that freedom from spectacles becomes the normal expectation after surgery.
- Technology firms will develop safe methods for remotely charging power cells inside lens implants so that they can incorporate energy-using functions.
- Further technology developments will lead to development of lens implants which can stream media as well as give good vision. So for example, you might be able to activate your lens implants with a voice command to superimpose satellite navigation information onto the world in front of you, a little bit like the heads-up display on a car windscreen.
- Diabetic monitoring. The clear fluid inside your eye can be used to monitor blood sugar levels. Scientists are developing sensors which could fit onto lens implants and provide very accurate information on diabetic sugar control.
- In a similar way, sensors on lens implants could be used to monitor pressure inside the eye and help manage glaucoma before any damage is done to vision.
- A combination of the above changes will lead to lens surgery becoming a common lifestyle choice for young adults.