I had this interesting question from Sophie:

Dear Mr. Allamby, My father has keratoconus, I believe he has had it a long time but was diagnosed officially at an eye test when he was 30 (he is now 50) will this affect my chances of laser eye surgery and would it be safe to proceed if I show no current symptoms (I am 21).

Many thanks, Sophie

Dear Sophie, Thanks for your question. Keratoconus (KC) is most often sporadic (not apparently inherited) but has been observed to run in some families. Typically it is first seen in adolescence. Around 80% of cases do not progress. As you are now 21, if you have KC there may well be changes in the corneas already so the best next step would be to see you for corneal scans. These are now very sophisticated at picking up even early changes of KC before they would affect your vision.

We perform thin-flap femtosecond LASIK with our new Crystal Line Ziemer down to 500 microns central corneal thickness (CCT). Below that we would normally do PRK, and also PRK if there is any slight irregularity in corneal shape. However, it is the appearance on the scans that is more important in your case, and CCT is only one of the risk factors we look at when considering suitability.

I am rather obsessed with safety, and any doubt whatsoever means I would advise against any treatment, even if you were very keen!

I had this interesting question recently from Kevin:

Hi Doctor, Would you please advise if “zlasik” is still better and newer technology compared to “ilasik with iFS Advanced Femtosecond Laser”?  Thanks

Hi Kevin, I prefer the Ziemer system (Z-LASIK). We have the brand new Ziemer LDV Crystal Line system, currently the only one in the UK, and it is a remarkable flap creation tool. It has a 33 times faster repetition rate than the latest iFS 150KHz model, with energy per pulse far lower, tighter energy focus and the shortest suction-on time. We can do both eyes safely and very accurately in around 6 minutes.

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Kate asked:

Hi,

I’ve been to consults at two clinics, one that does PRK, and the other LASIK (with a blade). Both clinics offered a similar quote and both said I was an ideal candidate for the surgery (I’m a healthy 23 year old female with mild astigmatism and the same prescription of -1.5 in both eyes since I’ve had glasses (2001). The only thing a out of the norm is that my corneas are a little steep (46). Is there going to be a benefit to me choosing one surgery over the other?

Cheers, Kate

Julie asked:

Dear Dave, I am about to get an enhancement surgery since my eye changed to -1.0 after just 10 months. I got the flap cut with the laser. I see that this type of cut heels quickly and I know doctor will not be using the cutting laser again, so how is he going to lift the flap? I’m terrified and thinking that I will be better off wearing glasses again. What do you think?  Thank you

Hi Julie
We lift flaps manually, using a special instrument designed for lifting, which is usually a fairly simple process. It should be possible to lift a femtosecond flap at 10 months, but you wont know until it is tried. I had one patient that proved impossible to lift after 6 months, but that was unusual. You could opt for PRK enhancement with mitomycin, but I would opt normally to lift the flap first. You can discuss this with your surgeon before going ahead.
We are now hitting 100% for patients seeing 20/20 or better at my clinic, Focus, so enhancements are getting increasingly rare. If they do happen, it is usually for patients with very high myopia.
Best regards, Dave

Winston asked:

I am 19 , with -6.25 in the left eye and -7.25 in right. I have been wearing glasses for about 9 to 10 ten years.
What would you recommend? I do boxing as well as other physical activity.

Meera asked

Trudi asked

Hello Dave,
I had my eyes lasered in Dec 2009. My prescription was SPH -4.50 & -5.00. My left eye (which had the worst prescription) is perfect! I have had enhancement surgery on my right though as a slight astigmatism remained. I had enhancement surgery (using the LASEK method this time round) 4 wks ago and the vision is not yet as good as it was after the first surgery, before the enhancement. I am beginning to think I should have lived with the result I had after the first surgery and been grateful. Do you think my eye will heal to at least what it was after the first surgery?

Also, I have regular post-op check-ups with various different opticians (dependant on who’s in on the day of my app) and each tells a different story about healing and drops. I have been told that keeping the eyes wet with blink drops is *very important* to aid healing. I have also been told by another optician that I only need to put drops in when my eye feels dry. What is your view?
Thanks.

Trudi, for the lubrication, I would recommend regular instillation rather than just when they feel dry. The nerves are lasered during the treatment and see the eye is somewhat insensitive for a while, so you may not be aware of some dryness and so not lubricate. Aim for 4-6 times a day over the next couple of months. I prefer the preservative free version (you can buy e.g. Blink or Refresh over the counter at Boots) which will be less irritant with regular usage over an extended period. These are the ones in individual droppers. One vial should last you a day, one drop in each eye every 3-4 hours.

For surface laser correction (PRK/LASEK) the full result can take months to fully settle and the vision is often a bit off at 4 weeks post-op. You should find it will settle more over the next 4-8 weeks.

Graeme just asked:

Hi Dave,

Two weeks ago I was treated with wavefront guided LASIK with Intralase by [clinic name deleted].

Although my vision was very good from the following day, I have had problems at night with severe starbursts, glare and halos around fluorescent lights (even indoors). I was told a couple of days ago that it will get better with time but since it’s hardly got better since day 1, I think there is a slim to no chance of this happening, especially as the eyes otherwise feel good with excellent vision.

Also, I was told a number of times that I had very large pupils which is why I needed wavefront guided LASIK to prevent my night visiion being affected. In hindsight and reading further on the Internet (which I now realise I should have done much more of) .

I guess I’m asking is there anything that I can do about this, anything I should ask them, e.g. pupil dilation, treatment area or anything like that to determine the reason for the starbursts and the fact that it hasn’t been done 100% correctly or I shouldn’t have been recommended as suitable? Or is there anything that can be done to improve it?

I wouldn’t obviously want further surgery but I’ve seen on this page info about more modern lasers and larger treatment areas that you have used which almost eliminate night vision problems. Could this be an option? Although I have paid out £3000 so far and so wouldn’t welcome another big outlay especially without guarantees of success. My main problem is that come the winter I won’t even be able to get to work if my night vision remains as bad as this.

I would be grateful for any suggestions or advice that you have.

Graeme, it is still very early after your treatment, so I think the advice from your clinic to wait is correct. I would normally allow 2-3 months for the vision to settle fully before looking if anything else needs doing, especially if it was a particularly large prescription. So please be patient for now.

Keep in contact with your clinic, and repeat testing at 4, 8 and 12 weeks post-op can help monitor your progress and relieve anxiety. You would want refractions and wavefront scans in particular, as night problems can arise from both low and high order aberrations. Low order means your prescription, but from your description your distance vision is excellent so not likely to be much prescription left – but you can confirm at your next visit.

It can occur if the treatment zone was significantly smaller than the scotopic (dark conditions) pupil size but clinics and doctors are well aware of this and modern lasers can treat a wide area of the cornea. You can ask about your dark pupil size and the full optical zone used at your treatment, as well as the total treatment zone (including the blend zone that feathers the treatment edges outside of the full optical zone area).

If the night vision problems persist, treatment is usually possible and will depend on the cause. Patience first though, as these symptoms can improve significantly yet. Give them the opportunity to assess and review your progress. Please let me know how you get on.

Ellie asked:

Hi Dave,
I got iLasik performed 4 weeks ago. Since then I got 3 exams and they show I still got -2 and -1,75 ( was -4,75 both eyes before the op) I also got very high pressure in the eyes – like 34-40…The doctor said it’s normal – comes from the eye drops and will go away, got new drops now, but still can not see clear, still got miopia that I can not watch TV or drive…is this normal?
I was told with Lasik the sight is improved right after the surgery, I still can see as far as my nose…What is next?
Thanks.

Ellie, No not common at all in LASIK surgery, but it is possible. Under-correction of that degree is rare but it is feasible that it could happen. The high pressure afterwards could have led to some increased swelling in the cornea which would change the vision significantly. The pressure rise occasionally happens with steroid drops, and rapidly goes back to normal once stopped.

As for what is next? You should wait around 12 weeks to let the eyes and corneas settle and ensure all swelling has resolved. You may find the myopia decreases more. If not, then the flaps can be easily lifted and eyes re-treated around 3 months post. Keep in contact with your clinic and let time pass to see how it settles. It’s still pretty early at 4 weeks.

It’s normal for some patients to need an enhancement to finish off the result. Our own clinic rate is less than 1% for myopia, and it can vary between clinics – but we ALL perform enhancement procedures.

Certainly must be disappointing as most patients see 20/20 or better the following day, and yours is a pretty big under-correction. Hang on though and I am confident that your end result should be good. Keep me informed of the outcome please.

Regards, Dave

Omar asked:

Good Afternoon Mr Allamby,
I’m considering getting some treatment on my eyes, but am very worried about the long-term effect cutting the cornea can have. As i get older and my eyesight deterioates. will the my eyesight be worse off than if i had just kept wearing glasses?

Omar, I think this is one of the most common worries that prospective candidates have when considering laser eye surgery be it LASIK or PRK. It is just over 20 years since we first performed PRK for short-sight, and just under 20 years for LASIK, so we have considerable experience of long-term results.

The long-term outcomes have been excellent to date. Regression is seen in the London PRK study in 1-2% of patients, with a partial return to myopia, but not as bad as the vision had been before without glasses.

Cutting the cornea (e.g. to create a flap or flap disc) has been around for decades. Lamellar cuts were made in the 50s, and the first mechanical keratome was first used in 1963. No long term problems were seen, except when too little thickness was left in the cornea. At my clinic, we use a high safety standard of leaving 300 microns in the corneal bed, after creating the flap with a femtosecond laser and using the excimer laser to reshape the cornea.

The main worry is in excessive weakening of the cornea. However, the incidence of bending of the cornea through weakness in post-LASIK patients is the same as the incidence of bending from a disease known as keratoconus (KC). So in normal LASIK where all the safety parameters are observed, we are not sure if LASIK actually contributes to corneal bending post-operatively.

The key here, as always, is rigorous screening pre-operatively and visiting a centre where you get sufficient time for your consultation. Some clinics do consultations in 30 minutes, or even less. Others (mine included) spend much longer. Focus consultations take at least 2 hours.

Choose carefully.

Marie asked:

I had a detached retina 3 years ago, I have just had the go ahead from Optical Express to say i can have laser but I had been advised by the Dr who did the detachment at that time never to have it done and also by Specsavers after my annual eye test. What would you advise?

Marie, It’s a good question. Does LASIK increase the risk of retinal detachment? Or does retinal detachment, which is more commonly found in short-sighted patients who incidentally have LASIK, happen anyway ?

The suction applied by the keratome or femtosecond laser during flap creation can put tension on the vitreous gel and retina, and theoretically increase the risk of retinal problems. What evidence is there for this?

At the 2009 AAO meeting in San Francisco, Dr. J Fernando Arevalo reported no apparent causal relationship between LASIK and retinal detachment. Over 11,500 eyes were examined retrospectively and the incidence of retinal detachment was found to be lower than the general population. The study included patients that developed a retinal detachment as far out as 13 years after the procedure.

In a 10-year review presented by Dr Vincenzo Pucci MD at the 2003 ASCRS international eye conference, laser refractive surgery for high myopia did not appear to increase the risk of either retinal detachment or re-detachment. His series comprised 2,809 eyes of 1,477 patients who had undergone either LASIK or PRK for the correction of myopia or myopic astigmatism up to -13 dioptres.

Together these studies support the conclusion that the retinal detachment rate after excimer laser surgery for the treatment of high myopia is not increased, compared with the natural history of unoperated myopic eyes.

In my practice, for a comprehensive safety approach, I usually have the eyes examined by a retinal surgical specialist to get the all clear before any laser eye surgery procedure. Also, this specialist will review the retina afterwards to be certain no new holes or tears have appeared.

Zoe asked:

I am interested in laser eye surgery, but am very short sighted(-10) would it still be possible?

Zoe, yes it certainly may be possible. It will depend mainly on your corneal thickness and pupil size in the dark. The best way to know is to have a consultation and have the measurements taken. Not all patients are suitable at this level of prescription though. If LASIK is not possible, PRK with mitomycin may still be.
The WaveLight laser that I use takes relatively little tissue per dioptre, so I find we often have a good chance to treat higher myopia. If there is not quite enough tissue in the cornea, and you are 40+, a good option can be to leave you between -1D and -2D, so at least you will be able to read without any glasses.

Anne asked:

Hi Dave,
I am in contact with your clinic re: having Lasik. I just have a couple of questions:

1/ What is your re-treatment rate?
2/ How many dry eye cases are persistent/long-term?

Thanks, Anne

Anne, our enhancement rate is under 1% for short-sghted patients, and slightly higher for blended vision patients (distance plus reading correction).
Our “20/20 or better” rate is 99.4% for short-sighted patients up to -9.00D.

We have seen long-term dryness in a handful of patients, out of thousands of treatments. I find it is a rare problem when patients are properly screened, and treated pre-op if there is some dryness present. The way we keep these rates very low is by being vary careful on who we operate on, and excluding those with significant dry eye.

Faisal asked:
I am short sighted, wearing glasses for almost 15 years. Just wanted to know whether I am a suitable candidate for laser eye surgery or not. Thanks

Faisal,
Being short sighted and wearing glasses for many years is typical. You will need a full consultation to determine if you are suitable for laser eye surgery. Some of the main factors will be the scans of your corneas, prescription, corneal thickness, and eye examination.

Steve asked about cTen laser correction:

Hi Dave. Thanks for providing this blog, in anticipation of surgery it’s very much appreciated.
I’ve heard of a superioir procedure called CTen which seems to be a significant advance in corrective eye surgery, but can’t find any providers. Can you shed any light?

The cTen system is from an Italian company called iVis Technologies. It incorporates a 1,000-Hertz excimer laser (iRES) and a software planning system called CIPTA. cTen is an acronym for Customised, TransEpithelial, No-touch surgery.

It is promoted for complex cases where there is irregularity of the cornea, e.g irregular astigmatism. They use the excimer laser to remove the epithelial skin layer and use topography information from a Scheimpflug camera scanner to correct imperfections across the cornea stroma. The makers suggest this is a bette way of performing PRK.

Not really a significant advance as all this technology is currently available. We use the same Scheimpflug approach already with our WaveLight laser in its T-CAT (topography guided) mode, and all lasers can be used to remove the epithelium down to a desired depth the leave a smooth surface.

For virgin unoperated eyes, there is no significant benefit to use the CIPTA platform. The procedure here is just PRK. Also, the no-touch laser removal of epithelium approach adds little, as standard alcohol based removal is quick, effective and predicable, and is used around the world as standard. I do agree with iVis that topography guided correction is most useful for irregular corneas over wavefront guided, and I use T-CAT for these complex cases.

The above helps explain why you can’t find any providers. The gold standard procedure for us is thin flap femtosecond Z-LASIK. If we need to do surface laser, we do PRK.