Laser Eye Surgery- What you need to know
I have wanted to have laser eye surgery for the last 20 years. I first started wearing glasses when I was 8 years old, and have hated them ever since. I progressed onto contact lenses as soon as my Mum gave me permission, but though they’re great I do have some issues. They’re costly, my eyes get dry and I can’t wear them 24/7 or swim with them. I dabbled with day/night lenses (you take them out once a month) but didn’t agree with them, and thought longingly about laser eye surgery.
I had my first consultation four years ago (you should wait till you are in your twenties and your eyes have stabilized) and was told that I wasn’t suitable. I have a high prescription (-7.5 Dioptres) but this alone wasn’t the main factor, as I also have thin corneas, and combined this simply wasn’t a safe option. I sadly gave up on my dream, but recently I decided to go for a new opinion- techniques have progressed and I might be candidate now. I wanted to be prepared so I researched all the types of laser eye surgery that are now on offer, and though I would share this with you. There’s a lot of information out there and some of it can be quite confusing, so I’ll try and decode the laser eye surgery process in this piece.
There are currently THREE types of laser eye surgery performed in the UK, as well as contact less implantation (called ICL) for those who aren’t suitable for any of these options.
PRK
PRK stands for photorefractive keratectomy. This used to be the most common laser technique till newer ones were introduced, and this generally is the one offered by those clinics when you see those ‘£200 per eye’ deals. It involves the DR removing some of the cells on the epithelium (this covers the surface of the cornea. It’s very thin and is quick to heal when the cornea is injured). It involves no cutting of the cornea, but creating a ‘scratch’ along the surface, which is then treated with the excimer laser to help reshape the eye. The fact that you don’t need to create a flap means the eye will heal more cleanly, but the recovery time will be around a week, so you should prepare for a week off normal activities. Complications include infection, scarring, over correction and devloping astigmatism. Issues with light such as sensitivity and halos can be a concern. Corneal haze is the most common, where you’d experience some objects with a light haze around them. Post surgery bandage contact lenses are placed in the eye, which are taken out around 4 days later. Vision is blurry while they are in but tends to improve quickly when they are out. PRK is not performed at many places nowadays as most clinics offer LASIK and LASEK instead.
LASEK
LASEK is the newest procedure available, and is very similar to PRK in terms of approach and method. LASEK stands for Laser-Assisted-Epithelial-Keratomileusis. In PRK the cells of the epithelium layer are taken off, whilst in LASEK they are loosened with an alcohol solution. A laser is then applied to the surface of the cornea where it corrects the vision. When this is done (around 15 seconds per eye) the surgeon replaces the epithelium layer onto the eye ( or in some cases removes it completely) and places a bandage contact lens in the eye to protect it and provide comfort to the healing eye.
Recovery time is around a week, with vision improving once the bandage lens come out the eye. It can take up to six weeks to get ‘perfect vision’, though many patients experience good vision within two weeks. The eyes may be slow to heal, but the lack of a flap means that the eye health is better as no nerves were severed and that the eye will be stronger. This option tends to be chosen by people with thin corneas, and those who play contact sports ( a flap could become dislodged on contact, while this heals cleanly). I also want to mention that the laser used is clever enough that if you move your eyes during treatment it will stop lasering, so there’s no way you can mess this up by mistake. The same goes for LASIK as well.
Some places perform something called Epi-LASEK where the epithelium is removed with a laser rather than by hand. Some people suggest this aids healing, but other surgeons say there is no benefit to be gained from it. Top UK eye surgeon Professor David Gartry told me that he doesn’t use it as he feels there is nothing to be gained by it, and this is the man who brought laser eye surgery to the UK, so his word is pretty good.
LASIK
Lasik stands for Laser-Assisted-In-Situ-Keratomileusis. It can be used to treat myopia, hyperopia and astigmatism. This procedure is more invasive than LASEK and PRK as it involves a flap being cut into the eye. This can be done by the Doctor or using a a laser such as Intralase (with an added charge). The flap is then peeled back and then a cool beam of light from the excimer laser reshapes the front surface of the eye. Anaesthetic drops are applied before the start of surgery so you should feel nothing except a light pressure on the eye. The flap is then placed back down and will heal naturally. Eyes may feel gritty and watery after the operation and will be sensitive to light, so you need to wear sunglasses to go home and they may be sore for a few days. Eye shields need to be worn at night for around a week to make sure the flap doesn’t get dislodged during your sleep. A follow up appointment happened 24 hours later, and then check up visits are scheduled.
The benefit of this treatment is that vision improves almost immediately, with people able to go back to work and drive within 48 hours. This is currently the most common procedure in laser eye surgery, performed in around 95% of all cases. It can treat most prescriptions- from -1.00 to -10.00 (possibly even higher depending on the circumstances)
Wavefront Technology
Wavefront is not a type of surgery in itself, but it’s a way of performing laser eye surgery so I feel it deserves a mention. I’ve already spoken about how all procedures use a laser to reshape the cornea, but what I haven’t explained is that most lasers use a fairly basic pattern of prescription and shaping when they focus on the eyes.
Wavefront is a new(ish) type of laser, that maps the eye to create a custom shape that changes for each individual. It can used with both LASEK and LASIK procedures ( for an extra cost) and can treat higher prescriptions than a standard laser. the Wavefront laser identifies 20 points on the eye which are then matched with the machine and adjustments are made for size of pupils and eye positions. The laser uses a 3D eye tracker which follows all movements in the eye and keeps the laser centred to within 50 microns, so if you move during surgery you’ll be OK.
Wavefront was originally used in high end telescopes to help reduce distortion when looking into space, and now it’s used to measure and correct eyes- apparently its 24 time more precise than methods used for glasses or contact lenses. I think this should be standard with all laser treatments, but clinics like to slap a price tag on it (averaging an extra £800 per eye to use this).
For all procedures the aftercare involves a variety of eye drops taken multiple times a day and depending on the surgery, sleeping with goggles or eye patches for a short time is generally standard practice.
PERSONAL NOTE:
I was approved for the LASEK procedure! Initially my clinician thought I could have LASIK, but a second opinion showed the same cornea thickness problem I’d been diagnosed with before so LASEK is a safer option for me. I was a bit sad at first- more pain and longer downtime, but I’m happy I won’t have as many side effects (halos, etc) and I’ll be good to play contact sports (or start playing them as I don’t have any I do right now). The issue with my corneas is that when you create a LASIK flap you remove a certain amount of cells, and there is a ‘safe’ level for removal, as surgeons like to make sure you have at least 250 microns of tissue under the flap left in place. Some surgeons choose a higher number such as 280-300, which also gives them more cells to play with if they need to do a revision. In my case, creating a LASIK flap would take me onto the cusp of the minimum micron requirement and my surgeons (have had two opinions) weren’t willing to take that chance.
I know that no surgery is risk free and I am informed about the side effects, so I’m going into this eyes wide open. I just feel that I would have so much freedom without my glasses and a better quality of life, ans as eyes start to naturally deteriorate in your forties now is the best time to have it for me as I’ll have a decade to enjoy good eyesight. Over ten years the cost of surgery becomes equivalent to paying for glasses and contacts, so I fell like I’m making an investment in me- and saving money in the long term.
I’m having my surgery this weekend, so you can look forward to a post detailing the procedure, the results, and the aftercare.
Terms to know:
Cornea; the cornea is a dome shaped window covering the eye. it provides most of the eyes focusing power and has more nerve endings here than anywhere else in the body. on average it’s half a mm thick and has 5 layers.
Epithelium: The epithelium covers the surface of the cornea. It’s very thin and is quick to heal when the cornea is injured. this is what needs to be removed/ opened when you have your laser treatment.
Excimer laser: This was first used for vision correction in 1987. It works by producing a beam of UV light that is absorbed when it reaches high water containing tissue- such as the cornea. It doesn’t penetrate further so it’s safe to used, and works on the surface, keeping surrounding tissue safe whilst sculpting the corneal area.
