Have pressing questions about cataract surgery? Jaheed Khan has the answers
In this post, we continue our interview with Jaheed Khan, London Cataract Surgeon, and discuss cataracts.
Jane: When is the right time for people to have cataract surgery?
Jaheed: Okay, so “when is my cataract ready for surgery?” is a very common question. In the old days, we used to wait for them to ripen and that was a sort of layman’s term for when your cataracts got very, very severe. The reason we used to wait in the old days was that cataract surgery used to be a little riskier, and maybe we would not take the risk with the cataract operation if it was mild. We would just let people cope with the symptoms.
We are lucky today that our cataract surgery techniques have become very, very safe and become very, very technically much more accurate with much less infection risk.
So, today we tend to operate on our patients when they have symptoms, and symptoms of cataract can vary from very, very mild symptoms such as glare at night to constant blur like looking through a fog all the time.
There is a huge spectrum of symptoms. Occasionally, some people can have very mild cataracts and have very severe symptoms. Sometimes, they can have very mild symptoms with severe cataracts. So, it is a spectrum, and we need to talk to the patient and see how it affects their lifestyle, and if it changes it significantly, then we offer cataract surgery to improve it because there is no real point in waiting.
Jane: And how is cataract surgery done? Is it done under local anaesthetic or general anaesthetic?
Jaheed: I would say that about 90% of my patients have a local anaesthetic for the cataract surgery. The main reason being that surgery is very quick. It does not take very long. The average surgical technique takes about 10-15 minutes and can be done through small openings which can later seal on their own without the need for prolonged surgery. If we can give people drops and injections around the eye at the time of surgery and keep them awake, they manage fine. They just have to lie still under a microscope.
The other 10% of patients are the ones that are very nervous, and sometimes they could do with a bit of sedation while they are awake.
Jane: What sort of sedation do they get?
Jaheed: It depends on the anaesthetist’s decision, but most of the time it is a very light sedation which makes you a little bit more relaxed; it does not necessarily put you to sleep.
Jane: Is that something by mouth or …
Jaheed: Usually into the vein. We can do things if people are needle phobic, we can give them oral sedation as well, just before the surgery. The smaller minority of patients are my younger patients and my very nervous older patients who do not like the idea of having an operation while awake and we offer them general anaesthetic where that is indicated and where it is safe. So, we have a huge choice, and we tailor it to each person.
Jane: I am sure that patients knowing that they have got the options of local or a little bit of local sedation or general are very reassuring. So, often a patient will go to their optician for glasses and the optician will say “oh you have got a little bit of cataract”, and so with trepidation, they come along and see you, the ophthalmologist. What would happen to them on the day that they come to see you?
Jaheed: Knowing that referral, we will obviously check everything about their eye health. We will take a detailed history and make sure that there are no other conditions that affect their eyesight, but their actual examination would involve a full eye examination which would involve dilating the pupil, looking at the cataract and looking at the back of the eye as well. And, we would do some screening tests because we always like to know if there is any other concurrent pathology. For example, in someone who is elderly and has cataracts, there may be a chance that they have macular degeneration that goes undiagnosed.
So we would do what we call photography, and we would do optical coherence tomography scanning just to make sure that if they did go on to cataract surgery that that would be an improvement if they underwent surgery and that there would not be another reason for the blur.
Jane: Yes, they could have two different conditions I suppose, cataract and a retinal or macular change such as age-related macular degeneration.
Jaheed: And, often, they do. It is very important that you look for it and I tend to discuss all the needs of my patients and what their specific requirements are. Some patients need to be able to drive at night and have troublesome glare that they notice at night – it is worth doing a cataract operation to improve that.
In some people who have very mild symptoms, I am quite happy to watch and leave their cataracts, and I am more than happy to monitor those over a period.
What we do know is that cataracts tend to get worse. They sometimes gradually worsen, and sometimes they worsen quite quickly. So there is always a window of opportunity at some point to do the cataract surgery.
Jane: The intraocular lenses you use in cataract surgery have been around for decades now. How have they advanced?
Jaheed Khan: So, the first intraocular lens was done in the 1950s, and it was a fairly crude sort of implant, which sat on the eye, but unfortunately in those days there were quite a lot of surgical complications
Jane: It was acrylic?
Jaheed Khan: Yes, acrylic. It was a compound, an artificial compound, which was clear and solid.
Jane: It was designed as an implant.
Jaheed Khan: It was designed as an implant.
Jane: Was that in this country or abroad?
Jaheed Khan: Sir Harold Wrigley first inserted an acrylic intraocular lens in St Thomas’ Hospital. The issues around implant surgery a few years back was that it incited a lot of inflammation. There was a lot of infection risk.
The implants were inert but incited a lot of reaction and what has happened with technology over the last two decades is that our implants have become much more stable. There are fewer reactions, fewer infection risks and they last a lifetime, so we do not have to replace them.
Furthermore, you can get different types of lenses, which focus light for distance. They can focus light for multiple distances.
We have also got the opportunity to design a lens, which can correct astigmatism.
So we have a lot of options with lenses to change which glasses we use for particular tasks and that depends on the patient.